EN030002-000746-University of Manchester

Office of the General Counsel Room 2.003 John Owens Building The University of Manchester Oxford Road Manchester M13 9PL

Tel: +44(0)161 275 2770

[email protected] www.manchester.ac.uk 29 April 2016

By Post and EMAIL The Planning Inspectorate 3/18 Eagle Wing Temple Quay House 2 The Square Bristol BS1 6PN

[email protected]

Dear Sirs PLANNING ACT 2008 APPLICATION FOR AN ORDER GRANTING DEVELOPMENT CONSENT FOR THE KEUPER GAS STORAGE PROJECT (“ORDER”) PLANNING INSPECTORATE REFERENCE NUMBER: EN030002 INTERESTED PARTY REFERENCE NUMBER: 10032024 THE UNIVERSITY OF MANCHESTER

Further to the Examining Authority’s Rule 8 letter dated 23 March 2016, please find enclosed:

1. Written Representations of the University of Manchester 2. Annexures to the Written Representations of the University of Manchester 3. Response to the Examining Authority’s Question 10.7.

In response to the Examining Authority’s Rule 13 and 16 letter dated 20 April 2016; I can confirm that the University will, subject to further discussions with the Applicant, attend the Issue Specific Hearing on the local environmental impacts and the draft DCO on the 25 May 2016 and the continuation of the Issue Specific Hearing on the local environmental impacts and the draft DCO on the 26 May 2016. Upon attending, the University would wish to speak on the issue of the potential for radio interference arising from the Order and would further reserve the ability to speak on any issue that arises during the course of the meeting that is of relevance to the University or that may otherwise be of assistance to the Examining Authority.

If, upon reading the University’s Written Representations, the Examining Authority considers it useful to attend Jodrell Bank Observatory prior to any Issue Specific Hearing (or at any point in the course of the examination) we are very happy to accommodate a visit. Please contact me as early as possible in order that the necessary arrangements can be made.

Yours faithfully

Julia Wentlandova Solicitor – Estates Office of the General Counsel

Keuper Gas Storage Project

Planning Inspectorate Reference: EN030002

Written Representation of The University of Manchester

Interested Party Reference Number: 10032024

1. Summary 1.1. Radio astronomy provides a unique view of the Universe, revealing material that cannot be detected by telescopes operating at visible or other wavelengths, looking into the most highly obscured parts of galaxies, and routinely producing images at higher resolution than any other telescopes. However, unlike any other type of astronomy, the ‘light pollution’ which affects radio telescopes in the form of radio transmissions and unwanted radio noise, is very powerful and all- pervasive. The future of radio astronomy relies on simultaneously maintaining the continued regulatory protection of key frequency bands, continued protection of radio telescope sites from the build-up of activity which generates radio interference, and continual development of radio astronomy techniques to distinguish between cosmic and terrestrial signals.

1.2. Jodrell Bank Observatory (JBO) is the UK’s primary radio astronomy facility, operated and maintained by the University of Manchester and the UK Science and Technology Facilities Council (STFC). The 76-m Lovell Telescope is still the third largest steerable radio telescope in the world and operates more effectively now than ever before. It is used by hundreds of research astronomers from the UK and around the world, including almost all UK university astrophysics research groups. Jodrell Bank radio telescopes are used as part of international networks which combine signals from all of the largest radio telescopes in Europe and around the world.

1.3. Jodrell Bank carries out world-class research in many of the key science topics of modern astrophysics and also has a vital and well-established role in communicating that science to the general public through the Jodrell Bank Discovery Centre. Its contributions throughout the development of radio astronomy as a technique and a new branch of science are unrivalled in the world. Continued investment in JBO has

maintained its world-class status and further major investment is being made now to guarantee its future scientific competitiveness for the next 20 years or more. This combination of an unequalled heritage, world- class science, public engagement and ongoing development underlie the decision to host the headquarters of the International Square Kilometre Array at Jodrell Bank with the full support of UK government.

1.4. National bodies which administer the use of the radio spectrum (Ofcom in the UK) protect key frequency bands for radio astronomers and respect internationally recognised definitions of the levels at which interference into these bands causes harm to radio astronomy. However, the unintentional emission of radio signals by domestic or industrial equipment is not controlled by the spectrum allocation process.

1.5. The future of radio astronomy relies on simultaneously maintaining the continued regulatory protection of key frequency bands and protecting radio telescope sites from the build-up of activity which generates harmful radio interference.

1.6. The proposed Keuper Gas Storage Plant poses a potential risk to JBO operations. By way of illustration, the high power compressor installations alone may generate radio frequency interference above the level deemed harmful to radio astronomy. It is important to note that other elements of the proposed plant may also generate radio frequency interference and as such, the proposals need to be considered as a whole. The appropriate criterion is to demonstrate that the internationally agreed thresholds set out in ITU-R RA.769 are not exceeded.

1.7. The Applicant has not assessed the potential for likely radio frequency emissions to cause harmful interference at JBO. There is no analysis of the effect of the equipment likely to be used on radio telescopes, despite the national and international importance of the JBO and the location of proposals partly within or on the periphery of the Jodrell Bank Radio Telescope Consultation Zone in local development plan documents.

1.8. In the absence of further information on the likely radio emissions from the proposals, JBO has used the maximum radiated power recommended for smaller systems under a British Standard as a benchmark. Using this benchmark, JBO estimates that in the absence of mitigation measures, there is the potential for proposed electrical equipment to produce harmful interference to the Jodrell Bank radio telescope which exceeds the internationally agreed threshold.

1.9. Further assessment work is required to assess the effects of these proposals. It is essential that before this proposal is permitted the Applicant is able to quantify the likely level of radio frequency emission in the key frequency bands used by JBO and demonstrate either that the emissions will not be harmful to the operation of JBO or that sufficient radio frequency shielding is installed by way of mitigation and maintained throughout the operation of the facility, to ensure that the efficient operation of the Jodrell Bank radio telescopes is not impaired.

2. Introduction 2.1. These Written Representations are prepared on behalf of the University of Manchester (“the University”) in response to Keuper Gas Storage Limited’s (“the Applicant”) application for an order granting development consent for the Keuper Gas Storage Project (“Proposed Order”).

2.2. They have been prepared primarily by Professor Simon Garrington whose professional details are set out at Annex 1.

2.3. The University is concerned about the potential impact that the Proposed Order will have on the work undertaken at the University’s Jodrell Bank Observatory (“JBO”). Pictures of JBO appear at Annex 2.

3. What is radio astronomy and why does interference matter?

3.1. Radio astronomy is a branch of astronomy which involves the study of radio energy or radio waves emitted by objects in space.

3.2. Radio waves are part of the electromagnetic spectrum. Visible light is one form of electromagnetic radiation; other forms are radio waves, infra- red, X-rays and Gamma-rays. These different forms of “light” have different wavelengths, ranging from several metres for radio waves to less than one billionth of a millimetre for gamma rays.

3.3. Any object, including an object in space, will generally radiate energy across some part of the electromagnetic spectrum, with a broad peak in the emission at a particular wavelength. At longer wavelengths (such as radio waves), the energy emitted is much less. The Sun has a peak emission in the optical part of the spectrum, to which our eyes are adapted to work. At radio wavelengths, approximately one million times longer than optical wavelengths, the Sun (and indeed any other normal star) is very faint: much more than a billion times fainter at radio than optical frequencies. By way of illustration, the typical signals which provide mobile phone coverage are more than 10 million times stronger than the radio emission from the sun, which is by far the brightest individual source of radio emission in the sky.

3.4. Astronomers study objects in space, including stars, galaxies and the gas between them, using instruments which operate at various wavelengths across the electromagnetic spectrum. The atmosphere blocks our view of space at most wavelengths: the only two ‘windows’ which allow observations from the Earth through our atmosphere are at visible/near infra-red and radio wavelengths. However, when viewed at radio wavelengths, the sky appears very different to the view provided by our

eyes or large optical telescopes. Radio astronomy allows the detection of phenomena in space which cannot be observed at any other wavelength, and the discoveries of radio astronomers in the second half of the 20th century changes our view of the heavens. The most common element of the Universe, hydrogen, can only be observed in its neutral state at radio wavelengths.

3.5. Radio astronomy requires the detection and analysis of extremely weak signal. What radio astronomers call ‘bright’ sources are exceedingly weak radio signals by communications standards. A single mobile phone at the distance of the moon would be comparable to the brightest radio galaxies in the sky. The objects which are now of most interest to radio astronomers are about 1 million times fainter than this, equivalent to picking up a single mobile phone at the distance of Neptune.

3.6. To receive such weak signals, radio astronomers use very large dishes equipped with radio receivers cooled to -260C and they collect data for long periods, sometimes for many days pointing at the same object or patch of sky.

3.7. Radio astronomers are therefore operating in a very challenging environment: their ‘sky’ is permanently bright with man-made radio signals which are much more powerful than the objects they are looking for. Radio astronomy is only feasible because a few narrow bands are protected for scientific use (with transmissions in those bands prohibited), because radio telescopes can be located away from highly populated areas, and because radio astronomers continue to develop techniques to mitigate the effects of these man-made signals. The future of radio astronomy relies on simultaneously maintaining all three of these: continued protection of key frequency bands, continued protection of radio telescope sites and continued development of radio telescopes, their receivers and data processing systems in order to reduce their susceptibility to unwanted signals.

3.8. Key technical terms are explained in Annex 3.

4. The importance of Radio Astronomy

4.1. Information at different wavelengths (or frequencies) has been a major contribution to our modern understanding of the universe. Radio astronomy played a crucial role in our understanding of the creation of the Universe, with the discovery of the radio afterglow of the Big Bang. The spiral structure of our own galaxy, the Milky Way, was first established by radio observations in the 1950s. Pulsars, rapidly spinning stars made of neutrons compressed to a sphere measuring only 20km across, were discovered in radio surveys. Radio astronomy often provides the only way to peer into the most dusty and violent regions of space where stars are being born, whether in our own Milky Way or in distant galaxies.

4.2. In striving for maximum sensitivity to weak signals from space radio astronomers have developed several technologies which have since become more widespread. These include the first large parabolic dishes (including the Lovell Telescope). Several key image processing techniques were developed for radio interferometry and the algorithms originally used for medical (CT) tomography were based on radio astronomy techniques. The fundamental terrestrial and celestial reference frames for precision measurements of positions on Earth and on the sky are based on measurements of quasars by radio telescopes, which define a highly stable grid of directions in space connected to fixed points on the Earth’s surface. GPS satellite timing and positioning is tied to this grid. The first direct measurements of continental drift and the first demonstration that the Earth’s rotation rate varies due to global climatic factors such as el Nino were carried out using radio astronomy techniques. Radio astronomers adapted their techniques for accurate cell-phone location. Other technologies which originated in astronomy

are now used in many other applications and we are all now familiar with infra-red imaging (search and rescue, thermal imaging) and radio imaging (airport security body scanners). Perhaps the most ubiquitous example is now Wi-Fi which was developed by Australian radio astronomers based on technologies they had built for analysing radio telescope data.

5. Jodrell Bank Observatory and its importance Observing facilities and scientific activities at Jodrell Bank Observatory Introduction 5.1. JBO was established when Bernard Lovell, who had developed airborne radar during the war, returned to the University of Manchester and started experiments to detect radar reflections from the ionization caused by cosmic rays (fast-moving protons and atomic nuclei entering the upper atmosphere from space). He quickly realised that the signals he received were dominated by radio interference (see further below), especially the broad-band impulsive signals created by sparking from the trams which then ran in Manchester. Seeking a ‘radio quiet’ location, he was recommended to investigate the University’s botanical research station at Jodrell Bank, Cheshire and began experiments there in December 1945.

5.2. The Jodrell Bank Centre for Astrophysics (JBCA), of which the Jodrell Bank Observatory is a part, is one of the UK’s largest astronomy and astrophysics research groups with 30 academic staff and 180 researchers, including 58 postgraduate students. Its research covers a very wide range from solar physics to cosmology; JBCA staff play leading roles in major international projects including Planck, the Dark Energy Survey and the Square Kilometre Array; JBCA staff have been awarded a number of prizes for their work over the last 3 years including the Chapman Medal, the Herschel Medal, the George Darwin Lectureship, the

RAS Group Achievement Award and the Kelvin Medal. The JBCA operates at the University of Manchester Campus and at the JBO site.

Lovell Telescope 5.3. The 76-m (250’) Lovell Telescope at the JBO is still the third largest fully steerable radio telescope in the world, almost 60 years after completion. Since its initial construction in 1957 it has been equipped with state of the art receiving and data processing equipment. It is continually upgraded and its performance improved so that it is still a front-rank instrument and carries out world-leading science.

5.4. The Lovell Telescope is used 24 hours/day throughout the year except for planned engineering and maintenance and emergency repairs. The majority of telescope observing time is for the University of Manchester’s pulsar research programme. Observations using the Lovell Telescope have built up an unrivalled database of precision timing results on hundreds of pulsars over more than 40 years. It is the combination of these data with present Lovell Telescope observations which makes Jodrell Bank a world leading centre for pulsar research.

E-MERLIN 5.5. The Lovell Telescope is used by JBCA as an individual telescope and is also the key element in e-MERLIN and international networks of telescopes for high resolution imaging and experiments to detect long period gravitational waves.

5.6. The e-MERLIN array comprises 5 large radio telescopes across the UK plus one or two of the telescopes at JBO (Lovell and Mk2). These are linked by a dedicated optical fibre network to a central processing hub at JBO. With a total span of 217km e-MERLIN is able to produce radio images with comparable resolution to those produced by the Hubble Space Telescope. It operates 24 hours/day throughout the year except for engineering and maintenance.

5.7. E-MERLIN is the UK’s national radio astronomy facility and is funded by the Science and Technology Facilities Council (STFC) in conjunction with the University of Manchester for the national and international astronomical community. It is used by over 500 astronomers around the world, including almost all of the UK university astronomy departments. It was awarded the Group Achievement Award by the Royal Astronomical Society in 2015 and is a unique facility: there is no other instrument in the world with its combination of resolution and sensitivity at centimetre wavelengths.

5.8. Its science projects cover a broad range, from detecting the pebble-sized material which forms planets around young stars; the physical processes of star formation; the evolution of galaxies and the black holes at their centres; and mapping the distribution of dark matter using gravitational lensing.

5.9. The £7.6M e-MERLIN upgrade included the construction of a national scale optical fibre network (at the time of installation the e-MERLIN data traffic requirement was ten times the total internet traffic in the UK); new receivers, signal processing electronics, software and a new correlator which combines the signals from up to 7 telescopes.

European VLBI Network 5.10. The Lovell and Mk2 telescopes both participate in the European VLBI Network which joins together up to 20 of the largest radio telescopes in Europe, Russia, China and South Africa, thus forming a single telescope 10,000km across and capable of resolving objects a few thousandths of one arc second across. The EVN is used by hundreds of scientists across the world. EVN observations account for typically 12 weeks per year.

Square Kilometre Array

5.11. The Square Kilometre Array (SKA) is the world’s major radio astronomy project. Arrays of hundreds of dishes and antennas will be built in Australia and South Africa, led by the International SKA Organisation, which has been based at JBCA/JBO since 2008. Jodrell Bank scientists have been involved in this project since its conception in the early 1990s and are now playing a key role in design: a 16-strong University of Manchester team based at JBO lead the design consortia responsible for signal & data transport.

5.12. In April 2015 Jodrell Bank was chosen, against fierce competition, as the site for the future headquarters of the Treaty/Intergovernmental organisation which will build and run the SKA for the next 50 years. Success involved major investment from UK government and the University of Manchester in the new headquarters building, a clear recognition of the value of the JBO site for such an organization, including proximity to operational and scientific teams using the Lovell Telescope and e-MERLIN. The extent of national support was expressed by the Chancellor of the Exchequer in a speech on 14 May 2015 which addressed the creation of a ‘Northern Powerhouse’:

“We’ve worked with the great universities of the north to make major scientific investments, like the quarter of a billion pound Sir Henry Royce Institute in this city, with links to Leeds, Sheffield and Liverpool. An idea that barely even existed a year ago. Or the new investment in the centre for ageing in Newcastle. And by having everyone from the Prime Minister down fighting hard for it, we’ve just made Manchester University’s Jodrell Bank the global headquarters for the new Square Kilometre Array – the largest experiment in the history of science.”

National and International Significance of Jodrell Bank Observatory

5.13. JBO has made major contributions to science since its inception and continues to carry out world-class scientific research. Scientists at Jodrell Bank have been involved in the discovery and/or follow up of almost all of the discoveries mentioned above. Key achievements, scientific and technical contributions by scientists at Jodrell Bank over the last 70 years include:

5.13.1. The construction of a fixed 218’ dish antenna and the first detection of radio waves from a galaxy outside our own Milky Way (1951); 5.13.2. The first ‘radio picture’ of the radio emission from a ‘radio galaxy’ (now known as Cygnus A) and the realisation that radio astronomy was showing us completely unexpected phenomena which had not been seen by optical telescopes; 5.13.3. The discovery of compact radio sources later identified as ‘quasars’ at great distances powered by massive black holes (approximately order one billion times the mass of the Sun), completely transforming our view of the Universe; 5.13.4. The discovery of the first ‘gravitational lens’ in the 1970s, confirming Einstein’s prediction that the images of objects in space could be distorted and split by the bending of light purely by the mass of an intervening object; 5.13.5. The discovery using the Lovell and other radio telescopes of the double pulsar, allowing the most stringent tests of general relativity to date; 5.13.6. The creation of the world’s first large-scale radio array to be connected by a dedicated optical fibre network, e-MERLIN.

5.14. JBO is of wider national and international significance in the following ways. The construction of the Lovell Telescope in the 1950s was an unprecedented feat of engineering for the purpose of a brand new scientific discipline and its progress was followed by politicians, media, the general public, and the national and international scientific

community. When Sputnik was launched in October 1957 (just as the telescope was being completed), the Lovell Telescope was the only instrument in the world which could and did track by radar the inter- continental ballistic missile used to put the world’s first artificial satellite into orbit, instantly raising the awareness and significance of the telescope.

5.15. The Lovell telescope has played a significant role in the exploration of space: it was used to track the first spacecraft ever to reach another celestial body (Luna 2 impacting the Moon); pick up the first pictures sent from the Moon’s surface (by Luna 9); track the descent of the Eagle lander during the first manned landing on the Moon; and send command signals to the Pioneer V spacecraft during the first US deep space missions.

5.16. Until the completion of the Fylingdales early warning radar system (including the period of the Cuban missile crisis) Jodrell Bank acted as the UK’s only option for the detection of incoming ballistic missiles.1

5.17. The first International Astronomical Union meeting on radio astronomy was held at Jodrell Bank; Jodrell Bank was a founder member of the European VLBI Network (EVN) and the European pulsar timing network (EPTA and LEAP), both of which are important ongoing international facilities. The first major EC collaboration in astronomy RadioNet was originally co-ordinated by Jodrell Bank and has continued since 2004 with approximately €25M funding for radio astronomy in Europe since then. The scheduling for European (indeed global) VLBI observations at cm wavelengths is done from Jodrell Bank, and scientists from Jodrell Bank have frequently chaired the EVN Consortium and the committee which allocates its observing time across Europe.

1 Smith, F G ‘Diversions of a radio telescope’, Notes and Records of the Royal Society (2008) 62, 2 13

5.18. JBO is a rare case of an international ‘Big Science’ facility in the UK that is readily accessible by the general public. The Jodrell Bank Discovery Centre is one of the UK’s major science centres for the public and attracts over 160,000 visitors per year2 who are able to see the Lovell Telescope in operation.3

5.19. Jodrell Bank Observatory has also been placed on the UK’s shortlist (of 11 locations) for nomination as a future World Heritage Site. The Lovell Telescope has been a Grade I listed building since 1978.d

5.20. The national and international significance of JBO sees continual investment in the JBO site. Details of the recent investment is set out at Annex 5.

6. Spectrum protection for Radio Astronomy

6.1. As stated earlier, the strength of radio signals received on Earth from astronomical sources (even including the Sun) are very much weaker than those used for broadcasting, communication and radio-navigation. Radio astronomy therefore relies on certain parts of the spectrum (frequency bands) being protected from interference for scientific use, by prohibiting or restricting transmissions in these bands. The nature and adverse impact of interference is explained later.

6.2. The use and protection of the radio spectrum for commercial, public, scientific and defence purposes is regulated by the International Telecommunications Union (ITU), a specialized agency of the UN. The

2 Events include: frequent lectures; daily science talks by Jodrell Bank Observatory staff; concerts with linked science fairs attended by up to 12,000 people; targeted provision for schools and girls in science. All these initiatives inspire young people into to scientific (STEM) subjects, demonstrate feasible career paths in science and show taxpayers the results of their contribution to science in the UK. The Jodrell Bank Discovery Centre has won many tourism awards. 3 Its status as a preeminent venue for astronomy in the UK is demonstrated by the BBC’s decision to use the Lovell Telescope control room to film Stargazing Live every year since 2011. This attracts over 3M viewers each night. When the then science minister David Willets gave a speech entitled ‘Great Britain: a great place to do science’ he chose to do so from Jodrell Bank Observatory. 14

ITU Radio Regulations (RR) follow from regular World Radio Conferences, and take the form of an international treaty to which participating member states (approximately 190, including the UK) are signatories. The most recent version was agreed in 2012. Radio astronomy is one of approximately 40 recognised radio services (mostly broadcasting, communications, navigation, defence) to which frequency allocations are made. Radio Astronomy was recognized as a service (RAS) in 1959. Radio astronomers work through their national administrations at the WRC. JBO has always been represented at the WRC by one or more senior staff members. Astronomers recognize that reserving spectrum for science is a significant issue and appreciate the need to balance the unique scientific and cultural importance of radio astronomy against other public benefits. In the UK a number of bands are protected for radio astronomy by a grant of Recognised Spectrum Access by Ofcom.

6.3. Radio astronomy is a “passive” service which measures natural radiation. Certain key frequency bands are determined by fixed physical properties (such as molecular resonance) that cannot be changed.4 The frequency allocations to RAS include several purely passive bands where all emissions are prohibited.5 Such bands may be shared with other passive users, notably Earth observation services. Some primary bands are shared with other secondary transmitting users who may not cause harmful interference to radio astronomy. Other bands are noted as important to radio astronomy and administrations are urged to take all practicable steps to protect radio astronomy when making frequency allocations.

6.4. One of the most important bands for radio astronomy is at 1400-1427 MHz in order to make observations of neutral hydrogen (HI) which emits

4 “Active” services make use of a variety of radiocommunication technologies to perform measurements and observations (eg satellite apparatus) and transfer back the collected data. In principle, these are less sensitive to interference than passive sensors. 5 RR footnote 5.340. 15

at this particular frequency (1420 MHz) and no other. 6 Most Lovell Telescope observations use this band, not to detect HI but because it is well protected and because the telescope is optimally efficient at this band.

6.5. In order to gain sensitivity for objects which have a broad (continuum) spectrum of emission radio astronomers may observe outside the most well protected band, or use a range which covers one or more protected bands. Since there are other protected bands at 1612 and 1665/7 MHz, observations may encompass the entire 1.4-1.7 GHz range.

6.6. Interference with observations in protected bands is explained further below.

6 It is also widely used by Earth observation scientists to make global measurements of surface temperatures and moisture content, which are essential for understanding climate change. 16

7. Sources and Impact of radio interference on radio astronomy Sources of radio interference

7.1. No transmissions are licensed by Ofcom within the fully passive bands or those where radio astronomy has a primary allocation. There may be coordination of use in some shared bands.

7.2. However electrically operated equipment commonly produces radio frequency emission as an unwanted product of its main function. Such interference may be in the form of narrow band emission, which can fall within the bands protected for radio astronomy or can be impulsive broad-band emission covering a wide range of frequencies including those bands protected for radio astronomy. The proliferation of even domestic electronic equipment, whether this be televisions or tablets, hairdryers or microwaves, is a growing concern.

7.3. The power drive systems (PDS) used in medium and large electric motors also involve rapidly switching voltages and are recognized sources of significant electromagnetic interference including radio frequency interference. We return to this below.

Impact: qualitative remarks

7.4. There are many types of radio astronomy measurements aimed at detecting many different types of astrophysical phenomena. There are many potential sources of radio interference, including the electrical equipment referred to above.

7.5. In almost all cases the radio signals emitted by astrophysical phenomena and measured by radio astronomy is extremely weak. The signals being sought are typically a hundred to a million times lower than the internal noise generated by the receiver, the atmosphere and the ground even with the very best receiver designs cooled to a few degrees above

absolute zero. By comparison, radio communications systems operate such that the signal is much stronger than the noise by a factor of a hundred or more, in order to deliver a clear signal. Radio astronomers can work successfully in this low signal-to-noise (S/N) regime because they can measure the average properties of the signal over long periods or across large bandwidths and detect small changes in the total noise level.

7.6. Interfering signals can be much more powerful than the radio astronomy signal and do not average out in the same way that receiver noise does. If these signals have sufficiently high S/N ratio in the radio astronomy data to be recognized as such, then in some cases they can be removed from the data either by deleting data for periods of time and/or across certain frequency ranges. However this impairs the efficiency of the telescope operation because valuable data is being lost.7 It may be possible to compensate for this by observing for a longer period, but this consequently impairs the efficient operation of the telescope. Interference may entirely prevent some observations which require data at a particular frequency or at particular intervals in time or frequency.

7.7. At very low levels interference may add to the system noise in such a way that it cannot be recognized but increases the general noise level. Such interference reduces the efficiency of the telescope operation because it makes the telescope less sensitive.8

7.8. Interference at a level which is not so strong that it is easily recognized but is comparable to the noise is hard to deal with and severely affect the results of an experiment or measurement. Almost all observations and

7 For a given receiver performance, the sensitivity reached depends on the factor √Bτ where B is the total bandwidth and τ is the period over which data are collected. Any reduction in the bandwidth or time due to data deletion reduces the factor √Bτ and hence the sensitivity. 8 The time required to achieve a certain sensitivity depends on the square of the noise level: increasing the noise level by 10% means that the observing time has to be increased by 20% to achieve the same sensitivity consequently reducing the efficiency of the telescope operation. 18

experiments already involve some form of optimal filter designed to maximise the response to the particular objective while minimizing the response to interference and noise.9 Such optimal filters work best for highly targeted experiments such as timing a particular pulsar and have much less advantage when carrying out a survey or search for new objects or unexpected phenomena. The fact that pulsar searches can no longer and are no longer carried out at Jodrell Bank, is an example of where particular projects become completely unfeasible because of interference.

7.9. Any impulsive interference which is not removed from observations of pulsars will degrade the accuracy with which the pulse arrival times can be measured. All of the pulsar observations with the Lovell Telescope, which account for 60-85% of all the observations made by the telescope, are aimed at timing measurements. These timing measurements are the basis of the most significant research carried out by the telescope: the understanding of pulsar timing behaviour to search for gravitational waves and test general relativity. Although much effort is put into removing the obvious impulsive interference events there are inevitably a large number which are below a recognition threshold but which collectively perturb the accurate determination of the pulse arrival times. This impact on the most important research carried out by the telescope is a reduction in the efficiency of the telescope in terms of its ability to receive radio emissions from space with a minimum of interference from electrical equipment.

ITU Definition of harmful interference for radio astronomy 7.10. The ITU defines the level of interference which should be considered as detrimental to radio astronomy measurements as 10% of

9 For example ‘folding’ data at the known repetition rate for a particular pulsar and optimising the spectral resolution for particular spectral lines. 19

the measurement error of radio power due to system noise (receiver, atmosphere etc) alone.

7.11. The basis and calculations for this definition are set out in the ITU Recommendation ITU- RA.769-2, which is the only internationally recognised standard for interference thresholds across the spectral bands used for radio astronomy currently in force. It is widely used by national administrations when dealing with frequency allocation. In the UK it is used by Ofcom as the basis for frequency allocations which may impinge on radio astronomy bands.

7.12. RA.769-2 specifies the limits for harmful interference to radio astronomy in a number of frequency bands which are protected for radio astronomy for continuum and spectral line observations.10 These limits assume that interference enters the receiver from a random direction and does not account for the fact that when a large radio telescope such as the Lovell Telescope is pointing directly at a source of interference, the received signal may be 100,000 times larger due to the gain of the telescope. Further, RA.769-2 assumes no gain from the telescope which is representative for the case when a telescope is pointed approximately 19 degrees away from a source.11 At smaller angles the signal will be greater (1000 times greater at 1 degree) and at larger angles the signal will be less, but never by more than a factor of 10.

10 RA.769-2 assumes a default observation time of 2000s, which is typical for pulsar observations at JBO. 11 Using the model of ITU-R SA.509. 20

8. Policy, Regulation and the Jodrell Bank Consultation Zone 8.1 Some radio astronomy observatories (notably Green Bank in the US and the SKA sites in Australia and South Africa) have defined ‘radio quiet zones’ surrounding the observatories within which there is legislative control on radio transmission and sources of radio interference. The ITU report ITU-R RA.2259 ‘Characteristics of Radio Quiet Zones’ contains more details and examples.

8.2 There is no such radio quiet zone in the UK and instead JBO has relied thus far on the consultation process established in the 1973 Article 11 Direction to the Town and Planning Act 1971 to safeguard its radio frequency environment by reviewing planning applications within a defined consultation zone.

8.3 Local planning policy seeks to protect the function of the JBO from interference pursuant to policy PS10 of the Congleton Local Plan (in respect of Cheshire East Local Planning Authority) and policy BE20 of the Vale Royal Borough Local Plan (in respect of Chester West and Chester Local Planning Authority), both of which take into account the Town and Country (Jodrell Bank Radio Telescope) Direction 1973. The Direction provides for JBO to be consulted on planning applications for development which falls within an identified zone.

8.4 Policy PS10 in the Congleton Local Plan (Cheshire East) states that “within the Jodrell Bank radio telescope consultation zone, as defined on the proposals map and inset maps, development will not be permitted which can be shown to impair the efficiency of the Jodrell Bank radio telescope”.

8.5. Policy BE20 of the Vale Royal Borough Local Plan (Cheshire West and Chester) states that “within the Jodrell Bank Radio Telescope Consultation Zone, as defined on the proposals map, development which can be shown to impair the efficiency of the Jodrell Bank Radio Telescope will not be allowed”.

8.6. Copies of the relevant Local Policies and the 1973 Article 11 Direction are set out at Annex 5. The geographic location of the Consultation Zone is set out in the plan at Annex 6.

8.7. There is no specific national planning policy which correspondingly addresses the particular issue of radio interference, or potential impacts on radio astronomy, but paragraph 5.21 of the Overarching National Policy Statement for Energy (EN1) states that decisions should “consider other impacts and means of mitigation where it determines that the impact is relevant and important to its decision”; and that applicants should “identify the impacts of their proposals in the ES in terms of those covered in this NPS and any others that may be relevant to their application”.

8.8. ITU recommendation RA.769-2, as explained above, is an important technical basis on which to consider policy which is addressed to potential impacts on JBO, for it specifies the limits for harmful interference to radio astronomy in a number of frequency bands which are protected for radio astronomy.

9. What the University understands the Applicant’s proposals to be 9.1. Based on the works set out at Schedule 1 of the draft Development Consent Order (“DCO”) (“the Works”), the University is concerned with the proposed Works at the Holford Brinefield main development area (“Main Development Works”) as it would appear that it is the plant and

machinery that will be housed in this area that could cause interference with the radio astronomy research undertaken at JBO.

9.2. The Main Development Works are situated both inside and outside of the Jodrell Bank Consultation Zone. We do not consider that the line of the consultation zone of itself delimits where potentially harmful interference may occur, but we would have expected that the location of at least some of the Works inside the consultation zone would have led to an assessment, within the Environmental Statement, of the potential impacts of emissions from equipment which could affect a material asset of the national importance of JBO.

9.3. However, the Environmental Statement contains no assessment at all of how the proposals would affect the JBO, or of any measures which have been considered to control emissions that could cause harmful interference.

9.4. In an attempt to obtain further information the University has met with the Applicant and we have also written to request more detailed information on the proposals. As we understand it the Applicant’s detailed design for its plant and machinery has not been resolved, such that we have been provided only with outline details on the type of equipment to be installed as part of the Main Development Works. Based on this information the University is primarily concerned with the gas processing plant (i.e. work No. 14), however, it should also be noted that the other Main Development Works do have potential to cause interference, possibly at a lower level, are greater in number and therefore of concern cumulatively.

9.5. As we understand it, work no. 14 involves the use of very high power gas compressors to handle the flow of large volumes of gas between the storage facility and the supply pipelines. It is understood that the main gas processing plant will use 4x 15MW compressors. The power drive

systems (PDS) of these motors are a significant concern in terms of their potential to cause radio frequency interference to the radio telescopes at JBO.

9.6. The Applicant has indicated that the equipment outlined, which we understand to include the PDS, will be designed to comply with EMC Directive 2004/108/EC as implemented in the Electromagnetic Compatibility Regulations 2006.

9.7. However, we are concerned that a simple reference to the Directive and the Regulations involves neither a proper assessment of the potential effects of the proposals nor an adequate guarantee that harmful interference to JBO would be prevented.

9.8. The Applicant has not explained how the Regulations would actually operate so as to avoid such interference in this case. They apply in part to electrical equipment liable to cause electromagnetic disturbance. Their “essential requirements” require all equipment, including apparatus and fixed installations (see regulation 4) to be designed and manufactured, having regard to the state of the art, so as to ensure that the electromagnetic disturbance it generates does not exceed a level above which radio and telecommunications equipment or other equipment cannot operate as intended.

9.9. However, as matters stand we have no information about how these requirements are to be satisfied, through the design of the equipment, or in particular the emissions which might be expected from it. There is no form of assessment to demonstrate how JBO would operate as intended. The Applicant has not provided sufficient technical analysis to demonstrate that the proposals, whether within or on the periphery of Consultation Zone, would not cause harmful interference as a new installation.

10. Potential for harmful interference from the proposals 10.1. The potential for a particular piece of equipment at a given location to cause interference to the Jodrell Bank radio telescope can be assessed by calculating the expected radio power received by the telescope from the equipment and comparing this to the threshold for harmful interference as defined by ITU-R RA.769. This is often done by calculating the minimum coupling loss (MCL) for a piece of equipment, given its expected radiated power at a particular frequency.

10.2. This approach is widely used in co-existence studies and has been described by Dr A Jessner.12 Some of the technical terms used in Annex 3 are relevant to this process. The MCL is the total radio path loss, including any mitigation/shielding measures, required to ensure that the power received at the radio telescope does not exceed the ITU-R RA.769 threshold.

10.3. As set out above, there is at present insufficient information on the radio power that might be received by the telescope as a result of the proposals. We understand from our own research that British Standard EN 61800-3 (“EN61800-3”) recommends limits of conducted and radiated electrical disturbances which can be produced for different categories of power systems (low and medium-power systems in categories C1, C2 and C3). However, for high power systems (category C4), there is no limit to the radio frequency emission which can be produced. Instead the installers are expected to develop an EMC (electromagnetic compatibility) Plan, taking into account equipment in the neighbourhood which could be sensitive to radio frequency interference.

12 Adv. Radio Sci. Jessner, A. (2013), 11, 1–8 25

10.4. Without any available estimate of the radiated power from any supplier, it is possible that the power may exceed the limit for a device in category C3 of EN 61800. In the absence of other information, we have used the C3 limit as a benchmark. The purpose of doing so is to assess whether there is at least the potential for emissions from equipment to raise concerns regarding harmful interference to JBO, in the absence of fuller information or assessment at this stage.

10.5. The radiated limit for category C3 equipment is 60 dBuV/m at a distance of 10m in a 120 kHz bandwidth. This is equivalent to an EIRP (equivalent isotropic radiated power) of -41 dBW in the 1400-1427 MHz radio astronomy band. This band is chosen because it is the most commonly used band for the Jodrell Bank telescope and it has the highest degree of protection. It should be noted that the radio emission from the power drive systems are likely to be stronger at lower frequencies, which are also occasionally used at JBO, and hence this is a conservative approach.

10.6. The minimum coupling loss (MCL) to ensure that this transmitted power does not exceed the internationally agreed threshold for radio astronomy (ITU-R RA.769) is then 178 dB.

10.7. The radio path loss at a frequency of 1420 MHz has been estimated using the procedure recommended by the ITU for the assessment of interference (ITU-R P.452 ‘Prediction procedure for the evaluation of interference between stations on the surface of the Earth at frequencies above about 0.1 GHz’). This is the internationally accepted propagation model for the purpose of interference assessment used in the communications sector. This method includes a complementary set of propagation models which ensure that the predictions embrace all the significant interference propagation mechanisms that can arise. It incorporates a calculation of diffraction along the specified terrain profile

between the transmitter and receiver as well as statistical treatments of effects for longer paths (>100km), including tropospheric scattering and anomalous propagation including surface ducting, elevated layer reflection and refraction. A terrain profile was retrieved from publicly available Ordnance Survey data at 50-m horizontal resolution. Specifications for typical local clutter in different environments and the associated height-gain variations are included. The basic input parameters used in this case were as follows:

Table 1: Parameters used in ITU-R P.452 propagation model

Parameter Value Comments (see also comments in text) Frequency (f) 1.42 GHz Key protected band for radio astronomy and most common observing frequency for Lovell Telescope Required time 50% Applies to statistical estimates for percentage (p) anomalous propagation. Specifies the probability that the loss is less than the estimated value. Typically, this is <10% for protection against interference. Station positions Specified through terrain profiles Antenna gains 0,0 dBi Assume omnidirectional antenna patterns for both transmitter and receiver. This is the default for ITU-R 769 Transmitter height 3m Receiver height 63m Representative Lovell Telescope focus height Average year/worst Average year The propagation models predict the annual month distribution of basic transmission loss. Refractive index lapse 45 N-units/km Estimated for UK from ITU P-452-14 Fig 11 rate (ΔN) Surface refractivity N0 328 N-units Estimated for UK from ITU P-452-14 Fig 11

10.8 The estimated path loss at the location of the proposed Gas Processing Plant is 116 dB plus any local clutter (other buildings, trees). The ITU-R P.452 prescription for typical clutter losses in a village, woodland or urban environment is 10-20 dB. Hence the expected total path loss between JBO and the KGSP plant is 116 + 20 (clutter) = 136 dB, which is 42 dB less than the required MCL.

10.9 On this approach, a single power drive system radiating at the C3 limit could generate interference which exceeds the ITU-R RA.769 threshold by 42

dB, (a factor of 16000), in the absence of shielding measures. Four such systems running together could exceed the threshold by a factor of 64,000.

10.10 It should be stressed that at this stage the radio frequency emission of the equipment is unknown, but could well exceed the C3 level by some margin.

10.11 The above analysis suggests that although the design of the equipment to be used has not been resolved, assumptions about potential radio emissions raise legitimate and substantial concerns regarding the potential for harmful interference as a result of the proposals, which requires further detailed assessment.

11. Existing interference

11.1. As explained above, there are many different sources of radio interference and these already affect the operation of the telescope. Many interfering signals cannot be filtered from the data, with the result that valuable data is lost, or observations are prevented. The cumulative effect of this interference is of growing concern and we have opposed other developments that are considered to bring a risk of harm to the efficient operation of the radio telescopes.

11.2. JBO has recently developed modelling software to build up a picture of the potential aggregated interference from the residential development surrounding the Observatory, out to distances of up to 40km. This has been prompted by concerns raised by recent housing proposals within the Consultation Zone. The approach is based on the premise that individual properties generate similar amounts of interference and that any differences are small when hundreds of thousands of properties are considered together. This modelling has been prepared in connection with opposition to residential development and uses a detailed path loss map constructed for this purpose. Extracts from work which describes the model are in Annex 7.

11.3. We have been unable to prepare a model to take into account all industrial facilities such as the current proposals, for the following reasons: there is no publicly available information on the geographical distribution of different types of industrial facilities; there is much less information on the likely strengths of emission from different factories and other installations where the equipment may be; and there is more variation between these sources of information.

11.4. JBO is aware that there are other gas compressors operating in same area as the proposed Keuper Gas Plant, including the Stublach and Holford Gas Storage Projects, but as matters stand it is not possible to identify the precise extent to which these facilities in isolation contribute to the existing interference and consequent impairment to the operation of JBO. As described above, the interference from electrical equipment is often intermittent and is not confined to particular frequencies, so it can be hard to distinguish individual sources of interference based on information gathered at JBO, even though the initial analysis set out above indicates the potential for such facilities to cause us concern. It may be possible to isolate some of these sources if information on the exact times of their operation were made available to JBO but in discussions with the Applicant JBO has been advised that such information is commercially sensitive. We are hopeful of obtaining further information from the operators of these projects, including any mitigation which is applied to the operation of equivalent equipment, and will update the examination accordingly, but at present are unable to isolate the contribution made by these facilities to interference which affects JBO. We are unaware of any work undertaken by the Applicant to assess the cumulative effects of these facilities.

11.5. In any event, the concern of JBO is to ensure that new proposals do not cause harmful interference as set out above. This must be assessed by identifying the proposed equipment which could produce radio

interference and carrying out a proper assessment of its potential effects, before identifying the extent of any potential mitigation to address the problem. The question of mitigation is considered below.

12. Interference Mitigation

12.1. Mitigation measures to reduce the impact of interference to radio astronomy are possible and may be useful in certain cases. These measures include control of activities likely to cause interference; installation of shielding to reduce the level of signals emitted; and techniques used in observing and processing radio astronomy data.

12.2. Unlike residential settings, there are reasonable opportunities to install effective radio frequency shielding to fixed industrial installations. Shielding measures include specially constructed cabinets and racks for drive equipment and other electronics likely to cause radio frequency interference. EMC filters can be used to reduce conducted and radiated disturbances. Additional shielding can be applied to the buildings housing equipment posing the greatest risk in terms of interference to external facilities such as JBO.

12.3. In order to guarantee that the KGSP Gas Processing Plant equipment does not cause harmful interference to the Jodrell Bank radio telescopes it would be necessary to specify that radio frequency shielding by a combination of cabinets and the surrounding building achieves a sufficient attenuation factor. Using the EN 61800 C3 limit just as an example, this shielding factor would be 42 dB at 1.4 GHz. If the radiated emission is likely to exceed the C3 limit by a certain amount, then the shielding factor will need to be correspondingly larger. If equipment generates more interference at lower frequencies, it should be noted that JBO carries out observations at frequencies down to 150 MHz.

12.4. There is however insufficient information to enable a proper assessment of the mitigation that may address the issues raised above.

13. Conclusions

13.1. Attached at Annex 8 is correspondence from both the Emeritus Professor of Physics at the University of Manchester and a Director of the Max-Planck-Institut für Radioastronomie in Bonn, which illustrates the national and international concerns with further interference affecting our work at JBO. The JBO is an exceptionally important and sensitive asset, potential impacts on which must be carefully considered.

13.2. As matters stand, however the available information demonstrates the need for further assessment of the potential emissions in this case. It may be possible to devise a scope of mitigation works which would avoid the potential for harmful interference as defined above and JBO will seek to work with the Applicant to ensure that, if feasible, mitigation could be secured through this DCO process. However, at the moment we are far from satisfied that the available information or assessment work is sufficient to demonstrate that the design of the proposals will avoid or mitigate further and unacceptable impacts on JBO.

Annex 1

Professional Details of Professor Simon Garrington

Annex 1

Professional Details of Professor Simon Garrington

1.1 Professor Simon Garrington is an Associate Director of the University of Manchester’s Jodrell Bank Centre for Astrophysics with responsibility for Jodrell Bank Observatory (“JBO”).

1.2 He was awarded a BSc in Physics (1st class) from the University of Southampton (1984) and a PhD in radio astronomy from the University of Manchester (1988) on the topic ‘Asymmetric Depolarization in Powerful Radio Sources’.

1.3 He has been a Director of JBO since November 2011 and Director of the e-MERLIN National Facility based at JBO since 2006. e-MERLIN is an array of seven radio telescopes, spanning 217km, connected by an optical fibre network to JBO. He manages and coordinates the scientific and technical operations of the JBO, develops its scientific and funding strategy and works with a range of stakeholders to maximize its scientific impact. As e-MERLIN Director, he manages and leads the scientific and technical operation of the e-MERLIN National Facility on behalf of the Science and Technology Facilities Council and the University of Manchester, including the completion of the e-MERLIN upgrade and continues to develop the scientific capabilities and national and international impact of e-MERLIN and VLBI (Very Long Baseline Interferometry: the combination of large radio telescopes across distances of thousands of kilometres).

1.4 Professor Garrington has been involved in radio astronomy research at Jodrell Bank since completion of his PhD in 1988. He was responsible for the e-MERLIN upgrade which has transformed the performance and capabilities of the MERLIN array with a new dedicated optical fibre network, new receivers and telescope electronics and a powerful new correlator at JBO. e-MERLIN was awarded the Royal Astronomical Society Group Achievement Award in 2015.

1.5 Following the experience with e-MERLIN, a team at Jodrell Bank now leads an international design consortium developing the data and synchronization networks for the Square Kilometre Array, a global project to design, construct and operate the world’s largest radio telescope, to be built in Australia and South Africa.

1.6 Professor Garrington is involved in many international radio astronomy activities, including European VLBI Network (“EVN”) Consortium which brings together up to 20 of the largest radio telescopes in Europe, Russia, South Africa and China. He has chaired the EVN Consortium Board of Directors and its Programme Committee which allocates observing time; he is a board member of the JIVE European Research Infrastructure Consortium which carries out the central functions for the EVN; he coordinate part of the EC-funded RadioNet initiative bringing together radio astronomy observational, technical and scientific resources across Europe.

1.7 Professor Garrington has worked with radio astronomy data from Jodrell Bank telescopes since 1984 and used many other radio telescopes around the world. He has authored 70 refereed articles on astronomy, almost all of which involve the analysis of data from radio telescopes. He speaks at international conferences on radio astronomy; referees astronomy articles for journals, reviews projects for funding bodies and assesses proposals for telescope time; has led the design, construction and commissioning of a national radio astronomy facility and has written large software systems for the acquisition, visualizing and processing of radio astronomy data, including dealing with radio interference.

1.8 Professor Garrington regularly participates in discussions and negotiations on spectrum protection for radio astronomy in the UK with Ofcom, the Ministry of Defence, Civil Aviation Authority etc and frequently represent STFC (the Science and Technology Facilities Council, the UK science funding agency and research organization for particle physics, nuclear physics and astronomy) in such discussions and negotiations.

Annex 2

Images of JBO and the Discovery Centre

Annex 2

Images of Jodrell Bank Observatory and Discovery Centre

The Lovell Telescope

Research at Jodrell Bank

Jodrell Bank Discovery Centre

School Visits at the Discovery Centre

Annex 3

Technical terms and glossary for radio astronomy

Annex 3 Technical terms and glossary for radio astronomy

3.1. Frequency, wavelength and bandwidth. Radio signals can be

characterized by their frequencies, which are typically in the range of 10 MHz (10 million cycles per second) to 100 GHz (100 billion cycles per second). The frequencies of some common radio transmissions in the region of 1-2 GHz are given below, along with some of the key radio astronomy bands. Ofcom maintain the UK Frequency Allocation Table. Approximate Frequency Use Remarks 700-800 MHz Digital Terrestrial TV regional transmitters 900 MHz Mobile phones base stations and handsets 1400-1427 MHz Radio Astronomy No transmissions allowed 1575 MHz GPS satellites 1610-1613 MHz Radio Astronomy 1710 MHz Mobile phones handsets 1800 MHz Mobile phones Base stations Etc

Since radio waves travel at the speed of light their wavelengths can be calculated as wavelength (metres) = 300/(frequency in MHz). So a frequency of 1420 MHz corresponds to a wavelength of 0.21m or 21cm. In order to carry information radio transmissions each span a range of frequencies, called the bandwidth. The higher the bandwidth the more information is transmitted per second. Typical bandwidths are 100 KHz for FM radio, 8 MHz for digital TV bands and 20 kHz for single mobile phone channels.

3.2. The dB scale: Radio engineers commonly use the decibel or dB to

express relative values of radio power. The dB is a logarithmic scale such

that 10 dB means a factor of 10 greater, 20 dB is a factor of 100 greater, 30

dB is a factor of 1000 greater etc. Similarly -10 dB is a factor 10 less, -20

dB a factor 100 less etc. The advantage of using dB is that in dealing with

transmitted and received powers most effects are multiplicative ie they

increase or decrease the signal by a certain factor: by using the dB scale to

represent both the power and these factors most of the required

calculations can be done by simple addition and subtraction. It must be

remembered however that 10 dB is always a factor of 10, so a signal at

−200dBm is 10 times stronger than a signal at −210dBm.

3.3. The dB prefix can be used to express absolute amounts: eg dBW is power relative to 1 Watt, so -30 dBW is 0.001W and dBm is power relative to 1 mW, so 20 dBm = 100 mW etc.

3.4. Received signal strength in radio astronomy is usually expressed using the unit of Janskys (Jy). 1 Jy means a power of 10-26 (0.00000000000000000000000001) Watts falling on an area of one square metre in a 1 Hz bandwidth. Even with a collecting area of 4500 square metres and a bandwidth of 27 MHz, the power received is 1.2 10-15 Watts. There are several hundred radio sources in the sky brighter than 1 Jy at 1420 MHz. Most objects studied by radio astronomers are much weaker, typically thousandths or even millionths of 1 Jy.

3.5. Antenna gain: radio astronomers use large antennas to collect more signal and hence amplify the weak signals they receive from space. A large antenna like the Lovell Telescope when pointed directly at a distant object amplifies the signal by a factor of 60dB ie 1 million. This high amplification is limited to a very narrow ‘beam’ of the telescope – about 0.15 degrees across. Away from the ‘beam’ direction, the amplification decreases rapidly, so that by about 15 degrees off the beam, there is no net amplification. At larger angles there can be a slight shielding effect although in practice this varies for different telescopes and varies with angle. In ITU-R RA.769, it is assumed that there is no net amplification for interference coming from a random direction.

3.6. Interferometry is the combination of signals from separated radio

telescopes to achieve higher resolution. The signals have to be combined coherently, so they need to be synchronized to very high precision, typically a few picoseconds. Arrays of telescopes such as e-MERLIN operated at Jodrell Bank combine signals from multiple telescopes in pairs and the resulting data is used to synthesise a radio telescope whose resolution (the level of detail in the radio image) is equivalent to a single telescope which a diameter equal to the maximum separation of the individual radio telescopes.

3.7. Tomography is the 3-D reconstruction of the internal structure of objects from external measurements, now most commonly used in medical imaging.

3.8. Ionization: at sufficiently high temperatures atoms may lose some (or all) of their negatively electrons. Such gas is said to be ionized.

3.9. Gravitational waves are ripples in space-time caused by the acceleration of massive objects in a similar way to the creation of electromagnetic waves by the acceleration of charged particles.

3.10. Dark matter is a component of the Universe whose existence has been inferred from the motions of stars and galaxies which respond to its gravitational pull, but which is not detected directly in any wave-band. The nature of dark matter and the type of particles involved remain unknown.

3.11. Gravitational lensing: massive objects bend the path of light or radio waves as they pass by, in a similar way to a lens which bends the path of light as it passes through the glass. A massive object such as a galaxy may therefore distort the image of an object which is directly behind it. This effect was predicted by Albert Einstein in his General Theory of Relativity and the first example of an distorted image of an

astronomical object was discovered by radio astronomers at Jodrell Bank.

3.12. Noise refers to the type of signals usually handled by radio astronomers. A signal consisting of noise has certain statistical properties and generally carries no information unlike a telecommunication signal which is designed to transfer information from one place to another. Natural astronomical signals are often noise-like except for the signals from pulsars, which are periodic, and emission from certain molecules and hydrogen which occurs at specific frequencies.

3.13. Continuum and spectral line observations: certain molecules and hydrogen gas emit particular radio frequencies related to transitions in their energy states. Historically emission and absorption features at well-defined frequencies are known as spectral lines after the dark lines which were first seen in the spectrum of a sunlight from a narrow slit. Most other radio sources emit over a broad range of frequencies. Hence observations may target certain spectral lines or be designed to cover a broad continuum.

3.14. Pulsars: are neutron stars (the ultra-dense core of a massive star which remains after a supernova explosion), which are only 20km in diameter, as massive as the Sun, and spin with speeds up to several hundred revolutions per second. The combination of spin and strong magnetic field gives rise to beams of radio emission which sweep past like a lighthouse, so that they are detected by radio telescopes on Earth as a very regular repeating blip. Their spin rate is very regular and they act as almost perfect cosmic clocks, ideal for carrying out experiments in fundamental physics, such as testing theories of gravity.

3.15. Quasars: are galaxies (collections of a 100 billions stars) with an 'active' super-massive (with a mass of a billion stars) black hole at their centres. This 'active' black hole is sucking in material and generating energy. Quasars which are bright at radio wavelengths produce powerful jets of material which drill their way through the surrounding gas, and

produce radio emission as they interact with this surrounding gas. The jets move at close to the speed of light, and hence can appear even brighter when they are directed towards the Earth.

3.16. dBuV/m (dB relative to 1 micro Volt per metre) is a measure of radio signal strength

3.17. dBi ( dB relative to an isotropic antenna) is a measure of the directivity of an antenna. An isotropic antenna responds equally to signals from all directions. An antenna with a gain of 0 dBi in a particular direction is equivalent to using an isotropic antenna, one with 10 dBi in that direction would collect 10 times as much power.

3.18. EIRP stands for Equivalent Isotropic Radiated Power

Annex 4

Investment at the Jodrell Bank Site

Annex 4

Investment at the Jodrell Bank Site

Lovell Telescope and Observatory Buildings

1.1. The University of Manchester is currently investing approximately £16M in structural work on the telescope and the observatory operations buildings primarily to maintain efficient operations of the Lovell Telescope (including its network operations) over the next 20 years.

1.2. The works on the Lovell Telescope started in 2015 and will continue for the next 5 years. These major works include: the replacement of the entire original 1957 surface with new galvanized and pre-painted steel sheet; the replacement of the main foundations of the telescope, involving the reconstruction of the 100m diameter concrete ring-beam with approximately 72 piles down to a depth of up to 30m; structural repair and modification to the ‘wheel girder’ which carries approximately 50% of the vertical load of the dish; design and installation of a new hydraulic upthrust system to deal with the variations in loading of the wheelgirder. In addition the University of Manchester is funding the purchase of a new focal plane array, which will increase the field-of-view and hence survey speed of the Lovell Telescope by a factor of 10.

1.3. The building refurbishments are designed to provide operations rooms, laboratories and offices for JBO staff. Previous extensions to the Control Building will be removed to highlight the original architecture of the (Grade I listed) building and a new sympathetic extension added. At the same time a new fully enclosed and shielded server room is being provided in the basement to enhance the radio-frequency shielding of operational equipment.

First Light Pavilion

1.4. In 2015 the Jodrell Bank Discovery Centre was awarded £12m from the Heritage Lottery Fund which will be part-funding for a prestigious ‘national-level’ £19.9m project: ‘First Light at Jodrell Bank’. The aim of the project is to support work that will lead to the award of UNESCO World Heritage Site status for Jodrell Bank and provide additional gallery space for the Discovery Centre in which the public can engage with the story of radio astronomy, from its early beginnings to the present day.

Annex 5

Local Planning Policy and Radio Telescope Direction 1973

Annex 5 Cheshire West and Chester – Vale Royal Local Plan – Jodrell Bank Radio Telescope Consultation Zone

http://maps.cheshire.gov.uk/cwac/localplan/?projectId=2535161&contentType=div&filename=section_1370863412000.html&contentId=ID-2535142- 1554&number=&mode=html# 86 Vale Royal Borough Local Plan - Policies saved after 29 Jan 2015

4 Built Environment

TELECOMMUNICATIONS DEVELOPMENT

Policy BE18

PLANNING PERMISSION WILL BE GRANTED FOR TELECOMMUNICATION DEVELOPMENT WHERE:

(i) THERE ARE NO MORE SATISFACTORY ALTERNATIVE SITES FOR TELECOMMUNICATIONS AVAILABLE; AND

(ii) THERE IS NO REASONABLE POSSIBILITY OF SHARING OF EXISTING FACILITIES; AND

(iii) IN THE CASE OF RADIO MASTS, THERE IS NO REASONABLE POSSIBILITY OF ERECTING ANTENNAE ON AN EXISTING BUILDING OR STRUCTURE;

(iv) THE PROPOSED DEVELOPMENT IS SITED AND DESIGNED SO AS TO MINIMISE ITS VISUAL IMPACT;

(v) SUBJECT TO THERE BEING NO SERIOUSLY DETRIMENTAL IMPACT UPON THE APPEARANCE AND CHARACTER OF THE BUILDINGS AFFECTED, THE AMENITIES OF THE OCCUPIERS OF NEARBY PROPERTIES OR THE CHARACTER AND APPEARANCE OF THE WIDER AREA AND LANDSCAPE.

Reasons and Explanations

(i) Planning Policy Guidance Note 8 sets out the Government's planning policy for telecommunications development. This policy reflects the Government's general policy on telecommunications, which is to facilitate the growth of new and existing systems. PPG8 also says that the Government is fully committed to environmental objectives. The policy allows decisions to be taken on planning applications which balances operational and technical requirements against any harm to the environment or residential amenity. In this respect, the Council will take into account whether the development is proposed by a 'Code Systems Operator' [i.e. a person who has been granted a license under Section 7 of the Telecommunications Act 1984 (power to license systems) which applies the telecommunications code to him in pursuance of Section 10 of the Act (the Telecommunication Code) in connection with the establishment or maintenance of a public telecommunications network.

Some parts of the Telecommunications Act 1984 have been replaced by the Telecommunications Act 2003 which will be referred to when considering planning applications for such development.

(ii) The Borough Council will refer to its Procedural Guidance on the Placement of Telecommunication Installations when considering applications for such development.

Policy Derivation PPG8 "Telecommunications" Cheshire 2016 Structure Plan Alteration Policy GEN3 Cheshire East – Congleton Borough Local Plan – Jodrell Bank Radio Telescope Consultation Zone

http://maps.cheshire.gov.uk/ce/localplan/congleton/# Congleton Borough Local Plan First Review (01/05) Plan Strategy Page 2-22

V) PROVISION OF LOCALLY REQUIRED UTILITIES ARE RELATED IN SIZE, POSITION AND DESIGN TO THE EXTENT AND NEEDS OF SETTLEMENTS AND THEIR RESIDENT POPULATION;

VI) PROVISION OF AMENITIES FOR THE LOCALLY RESIDENT POPULATION OR VISITORS IS SITED WITH DUE REGARD TO AVAILABLE MEANS OF ACCESS.

2.67 This Policy accords with Cheshire 2011 Structure Plan Policy R2. The areas of Special County Value are of strategic value to the County because of the quality of their landscape which should be protected from development. These areas also contain features of archaeological, historic or nature conservation importance which in combination with their landscape quality, need to be conserved and managed. The specific exceptions as set out in the Policy criteria I to VI to the general presumption against development in this policy are to allow for essential economic and social needs and opportunities for environmental enhancement.

2.68 The Structure Plan identifies two Areas of Special County Value (ASCV) in the Borough. The Congleton Cloud/ Timbersbrook/Roe Park/Mow Cop area is designated as an upland area characterised by small to medium-scale farmland with large blocks of woodland. It contains a variety of features unusual to Cheshire including moorland heather, dry stone walls, old rocky outcrops and long views out. The Dane Valley area is characterised by wide river meanders and meadows contained by steeply wooded buff slopes along with older river banks and slopes of cleared woodland. Within the context of Cheshire, this part of the River Dane has made more of an impact on the Cheshire Plain than other rivers.

JODRELL BANK RADIO TELESCOPE CONSULTATION ZONE

PS10

WITHIN THE JODRELL BANK RADIO TELESCOPE CONSULTATION ZONE, AS DEFINED ON THE PROPOSALS MAP AND INSET MAPS, DEVELOPMENT WILL NOT BE PERMITTED WHICH CAN BE SHOWN TO IMPAIR THE EFFICIENCY OF THE JODRELL BANK RADIO TELESCOPE.

2.69 The purpose of this policy is to take account of the Town and Country (Jodrell Bank Radio Telescope) Direction 1973 and to accords with Cheshire 2011 Structure Plan policy GEN5. Detailed consultations with the University of Manchester have taken place in order that the Local Plan’s major land use allocations, in particular those for housing, take account of the University’s requirements in respect of maintaining the efficiency of the Radio Telescope in terms of its ability to receive radio emissions from space with a minimum of interference from electrical equipment.

MAJOR EMPLOYMENT DEVELOPMENT

PS11

PROVISION WILL BE MADE ON THE EDGE OF THE FOLLOWING SETTLEMENTS FOR MAJOR NEW EMPLOYMENT DEVELOPMENT AREAS TO MEET IDENTIFIED ECONOMIC NEEDS:

REGIONAL EMPLOYMENT SITES:

Annex 6

Plan showing JBO, the Consultation Zone and the Main Development Site

Notes

Where dimensions are not given, drawings must not be scaled and the matter referred to Lambert Smith Hampton.

In the event of any dimensional conflict between Lambert Smith Hampton Drawings, the matter must be referred to Lambert Smith Hampton for clarification.

The Contractor must also refer to any separate Lambert Smith Hampton Specification to be read in conjunction with this drawing.

This Drawing is only for the use identified. Do not build from this drawing unless marked 'For Construction'.

2 Miles Addition of LA demarcation boundary and main development A 27.4.16 site split. A.D Rev Date Ammendment By

4 Miles Manchester Building Consultancy 6th Floor, 3 Hardman Street, Spinningfields, Manchester, M3 3HF Telephone: 0161 228 6411 Fax: 0161 228 7354 www.lsh.co.uk

Client The University of Manchester

6 Miles Project Jodrell Bank planning representation in respect of Proposed Keuper Gas Storage Overlaid Town Plan application (Ref: EN030002). 0km 1km 2km 3km 4km 5km Key: Scale 1:20000 @ A0 Scale Bar 1:20000 @ A0 Drawing Town and Country Planning (Jodrell Bank Radio Planning representation Telescope) Direction 1973 Consultation zone.

Keuper Gas Storage Main Development Demarcation line between (Cheshire West and Chester Keuper Gas Storage Ltd Drawing No. PLANNING Site (application No. EN030002). Council) and (Cheshire East Council). 13-03-01-HOL-24-511 Job No. DWG No. Revision

16.070 001 A The University of Manchester Jodrell Keuper Gas Storage Ltd Drawing No. Keuper Gas Storage Ltd Drawing No. Bank Site (Title No: CH591049). 13-03-01-HOL-24-510 13-03-01-HOL-24-512 Scale Date Drawn Checked As Specified 20/04/16 AD GT @ A0 Annex 7

Technical Analysis – previous modelling

Annex 7 Modeling the aggregated interference from development around JBO

1.1. It is possible to investigate the likely relative contributions from properties in the area around JBO, based on the number (and also size) of properties and the effective path loss (the amount that the signals are diminished as they travel from any given location to the telescope). This analysis requires the construction of a map of the path loss across a wide area and geographical information about the distribution of buildings.

1.2. The path loss depends on distance but is strongly affected by the intervening terrain. As discussed in section XX the appropriate method for calculating the path loss is specified in ITU-R P.452 which takes into account the way radio signals travel over a specified terrain profile.

1.3. Digital elevation data was obtained from the UK Ordnance Survey at 50m resolution, across the entire NW of Great Britain. These data are reliable and accurate, having been derived from higher resolution surveys, and many decades of measurements.

1.4. These data were used to create two 2-D grids of 1-D terrain profiles from each point to the location of the Lovell Telescope, one spanning 20km x 20km covering the Jodrell Bank Consultation Zone and a second approximately 100kmx100km centred on JBO at lower resolution.

Figure 1: Hill-shaded representation of the digital elevation data overlaid on a road map. The Cheshire plain between the higher ground of North Wales and the Peak District is visible. 1.5. The loss calculation for each pixel in the grid was done using software based on the publicly available implementation of ITU P452-14 and used the calculated terrain profile from each location to the Lovell Telescope. General parameters of the model were specified in Table XX. The procedure includes all aspects of the clear air prediction described above, but does not include local clutter (eg trees and buildings). For the loss mapping procedure, local clutter has not been included. ITU P.452- 14 provides a prescription to make estimates of local clutter depending on the urban/rural setting and path geometry, which can be added when required.

Figure 2: Radio Loss map at 1.4 GHz for the location of the Lovell Telescope, covering approx 100km x 100 km. the resolution of the map is 300m. Lighter colours show lower loss. This map encodes the vulnerability of JBO to inteference generated at different points i.e. a source of radio emission located in a lighter area will result in more interference.

1.6. The loss map quantifies the vulnerability of the Lovell Telescope to interference coming from different locations. It shows in considerable detail the locations which are more shielded such as river valleys and the lees and ‘shadows’ (with respect to JBO) of the hills which surround the flat Cheshire Plain, especially Alderley Edge to the NE, the Peak District to the E and the Sandstone Ridge to the W. The lighter regions show locations where there is a more direct line of sight to the telescope, including much of the Cheshire plain (except for the river valleys), and the slopes of the hills facing the telescope. Although this map bears resemblance to the ‘hill-shaded’ elevation map, it is based on a diffraction calculation along each line of sight from each location

1.7. The loss maps can now be used in conjunction with maps of the distribution of buildings to estimate the relative contributions from each location. For the Jodrell Bank Consultation Zone, Cheshire East Council provided extracts from their OS MasterMap which show the size, shape and classification of each individual building as vector ‘shape files’. A small part of the JBCZ lies in Cheshire West and Chester and is not included in these maps, but is included in the wider analysis discussed below. The data supplied includes a classification as ‘residential’, ‘agricultural’,’ commercial’, etc, which is also useful in excluding non- integral garages in counts of residential properties. Overall residential building account for at least half of the number of buildings (excluding garages) and in total approx. 6000 residential buildings were included.

Figure 3: Buildings within the JB Consultation zone, overlaid on a streetmap. Buildings data provided by Cheshire East

Figure 4: Selected area in Holmes Chapel showing colour-coded building types (Orange: residential, Blue; community, Green: Commercial) from Cheshire East MasterMap and grey outline of building clumps derived from OS VectorMap. Streetmap overlay from OpenStreetMap

1.8. In the simplest analysis it could be assumed that there is a fixed contribution per dwelling. On the basis that larger properties are likely to contain more electrical and electronic items, an alternative is to assume that the potential interference is proportional to the area of residential buildings. Without knowledge of the number of floors, it is impossible to account for multiple-storey buildings. In this first analysis only residential buildings have been included. In the following sections, all development will be included, but without classification. Future work will consider separate contributions from industrial facilities when more information about their likely emissions is available. An inner radius of 500m was chosen to exclude buildings within the JBO site. The results are shown in Figure 5.

Figure 5: Plot of modelled relative RFI contribution in 10 degree sectors from JB Consultation zone. Coloured bands show contribution from within 2,4,6,8,10km. Bearing runs anticlockwise from East going from left to right. RFI contribution assumed proportional to building area.

1.9. The plot of the potential RFI contributions from residential buildings within the JBCZ has some significant features: the largest contributions are expected to come from villages such as Goostrey and Lower Withington where there is significant population within 4km of the Observatory; Holmes Chapel although larger is significant but not dominant, because of distance and some benefit of terrain. The JBCZ does not include the nearest towns of Congleton and Middlewich

1.10. In order to assess the potential contribution from significantly larger centres of population at distances 1-40km from JBO, buildings data were taken from the Ordnance Survey (OS VectorMap District) at approx 1:50000 scale. These files represent buildings in small clumps which usually cover the building curtilage. For a comparative analysis, these clumps give a good indication of the total amount of development. The ratio of the clump area to actual residential building area is usually in the range 3-7, where the smaller ratio applies more to a village or small town environment (based on analysis of OS data). Large agricultural buildings and warehouses can have a disproportionate effect in this approach, since they have very large areas and relatively little human activity. The inner cut-off was applied to remove the disproportionate contributions of a few large agricultural buildings close to JBO, since there is no filter by building type: these large barns have areas equivalent to hundreds of houses but in general contain little electrical equipment. In total approx 133,000 building clumps were included in this analysis. The results are shown in Figure 6. The model based on building clumps has been compared to the version based on actual building areas within the JBCZ and there is close agreement.

Figure 6: Plot of relative modeled interference contribution in 10 degree sectors out to 40km radius using OS buildings data. Coloured bands show contribution from within 4,8,12,16,24,32,40km. Bearing runs anticlockwise from East going from left to right. Significant villages/towns/cities are marked.

1.11. This confirms the findings in para 1.9 from the consultation zone that the largest single contribution is from relatively local settlements rather than distant large conurbations. South Manchester and Greater Manchester at distances of 30-40 km are noticeable but are not dominant in this model. The increase in path loss due to terrain and distance more than offsets the large built up area.

1.12. A sector representation is shown in Figure 7 below:

Figure 7: Sector representation of interference contributions model. The base map is the distribution of building clumps (pink) from the OS on an OpenStreetMap. The coloured polygons centred on JBO represent the predicted aggregated interference from these building clumps such that the total interference in that direction is proportional to the radial distance on the map. The coloured bands include contributions up to the following actual distances from JBO: 1-4 km (black), 4-8 km (yellow), 8-12 km (light blue), 12-16 km (pink), 16-24 km (dark blue), 24-32 km (green), 32- 40 km (red). It is important to note that the coloured bands indicate the direction and strength of the predicted interference and do not correspond to the location on the map: for example the red band to the north corresponds to contributions from a distance 32-40 km to the North.

1.13. An alternative to the use of building clump areas to represent the potential contributions to interference is to use geographical population data from the recent (2011) census on the basis that human activity generates interference. On a sufficiently large scale, population mapping may be a valid representation of potential interference. A demonstration of this is seen in the comparison of light pollution and population density in Figure 8.. It is also likely that is some city areas that the ‘building clump’ area underestimates the population density and potential interference emission. Similarly, the building clump areas include large industrial and agricultural buildings which cannot be easily compared with residential developments. For these reasons, a population-based analysis may be more representative than a buildings-based analysis on large scales (the smallest available census zones have a median area of 6 ha and a population of 300 but have much larger areas where the population density is low). The population-based model is discussed below; the results are very similar to the buildings based model.

Figure 8: Illustration of the correspondence between light pollution and population distribution in the UK. The left hand image is a picture of the UK taken from space at night showing the glow from streetlamps. The right-hand image is a population map of the UK, with one white dot per person.

1.14. It is quite likely that is some city areas that the ‘building clump’ area underestimates the population density and potential interference emission. Similarly, the building clump areas include large industrial and agricultural buildings which cannot necessarily be compared with residential developments. 1.15. An alternative approach is to use a population-density data. The Office of National Statistics provide data from the 2011 Census. The highest spatial resolution data are at the level of Output Areas (OAs) which in the 100km grid zone around JBO have a median contained residential population of 299 and a median area of 6 ha. An example of OAs in Holmes Chapel is shown in Figure 20. For each of the 12,962 OAs in this zone, the loss map was evaluated at the population-weighted centroid of each OA. The population-based contribution to total interference for each OA can then be estimated using the loss value and the resident population.

1.16. Relative contributions can then be summed by various geographical areas using ONS-supplied lookup tables of OA to parish, local authority etc.

1.17. These contributions can then be integrated in 10 degree angular sectors as before. In order to put the population-based plot on the same scale as the building area-based plot it is necessary to relate the population count to the total building area. The total population and building areas in the 100km grid zone surrounding JBO are 3,947,465 and 368,978,336m2 respectively, so we use an overall scaling value of 93 m2/person. The comparison in Figure 22 shows that the two approaches – building area and population – give a similar angular distribution.

Figure 20: Map of Holmes Chapel showing the 2011 Census Output Areas (red lines), with the OS MasterMap buildings layer and OpenStreetMap

Figure 22: comparison of interference models based on buildings area and population data. 1.18. Contributions to radio emission from residential dwellings will include a wide variety of sources. The number of large domestic appliances (washing machines, dishwashers etc) might be best represented by the building count (typically one of each type per building), whereas general electrical installations might correlate more closely with building area and the number of small electrical and electronic items might be best measured by the population. The three approaches used here – building area, building count and resident population – all in fact give similar results in terms of the angular and distance distribution.

Annex 8

Supporting Letters

Jodrell Bank Observatory The University of Manchester Macclesfield Cheshire SK11 9DL

01477 571321 www.manchester.ac.uk/jodrellbank

18th April 2016

Dear Simon,

Pulsars and the Lovell Telescope

The Lovell Radio Telescope at Jodrell Bank has been used most successfully to study pulsars ever since their discovery at Cambridge nearly 50 years ago. The large collecting area of the telescope, advances in radio technology and its full steerability make it ideal for the task.

In order to study pulsars, we first have to discover where they are and to measure their basic properties through searches of the entire sky for pulses. In the 1970s and 1980s, the telescope made many exciting discoveries of new pulsars. However, the observations were being made against a rising background of impulsive interference, primarily from domestic and vehicular sources, such as electric switches, domestic appliances, automotive ignition, central-heating thermostats and air-traffic-control and meteorological radars. These can all mimic the emission from pulsars, and it is difficult to tell what is an exciting new pulsar or a faulty dish-washer electric motor. By the 1990s, the level of false alarms from local terrestrial sources made it impractical to to continue such searches and we reluctantly had to abandon them, leaving the discoveries to be made elsewhere.

Fortunately, precision measurements of previously-discovered pulsars which have well-defined properties are significantly less prone to the effects of impulsive interference and the group of pulsar astronomers at Jodrell Bank Observatory is now one of the foremost in the world in obtaining and interpreting the data obtained from these exotic cosmic clocks. Unfortunately, the ever-increasing levels of interference generated in the local area are now seriously degrading the data quality and are an important threat to these world-leading researches.

Yours faithfully,

Professor A. G. Lyne, M.A., Ph.D., FRS Former Director of Jodrell Bank Observatory, Emeritus Professor of Physics, University of Manchester

Combining the strengths of UMIST and The Victoria University of Manchester Max-Planck-Institut für Radioastronomie

Prof. Dr. J. Anton Zensus Direktor

MPIfR·Dr.Zensus·Postfach 2024 · 53010 Bonn Tel +49 (0) 228 525 378 Fax +49 (0) 228 525 439 Email [email protected] Prof. Simon Garrington MERLIN / VLBI National Facility www.mpifr-bonn.mpg.de/staff/azensus Jodrell Bank Observatory Postfach 2024 Macclesfield 53010 Bonn Cheshire SK11 9DL United Kingdom Auf dem Hügel 69 53121 Bonn

April 28, 2016

Dear Professor Garrington:

On behalf of the RadioNet Consortium of European radio observatories I am writing to express my strong support for radio frequency protection at Jodrell Bank Observatory. RadioNet is an Advanced Community that was established to facilitate coordination of radio astronomy facilities in Europe.

Radio astronomy uses one of the few windows in the electromagnetic spectrum that isn’t blocked by the earth’s atmosphere and allows us the observation of remote objects ranging from our own solar system out to the greatest cosmic distances. These enormous distances do however attenuate the radio signals so strongly that they are only detectable in an environment free of radio interference combined with the use of huge antennas, cryogenic receivers and highly sophisticated data acquisition and processing facilities. The sensitivity of a radio telescope improves with increasing antenna surface area and there are only a handful of large instruments such as the Jodrell Bank’s Lovell telescope in the world. The international scientific community shares these facilities in order to match their characteristics to the requirements of public funded research projects and of course to use them as efficiently as possible.

Nevertheless, there are so many such projects that all the large instruments, such as e.g. the Jodrell Bank Lovell telescope can cater only for 30% of the observing demands. Any deterioration, or even worse, the loss of such a facility, will automatically become a hindrance for scientific progress and in addition jeopardise the prospects of upcoming new scientists who largely depend on being able to use the large instruments for first class radio observations. In order to achieve the highest sensitivities (e.g. for the high precision pulsar timing LEAP collaboration) and highest spatial resolution (e.g. Very Long Baseline Interferometry, aka VLBI), the signals of the largest antennas are combined in simultaneous observations.

Our institute has and still is enjoying a very successful cooperation with the Jodrell Bank observatory, in particular in pulsar research and VLBI. This reflects the historic and still prevailing vital role of the Jodrell Bank observatory as one of the world’s few leading centres for radio astronomy which is also amply reflected in its scientific publication record. We would therefore like to express our concern about a possible degradation of the observational capabilities by radio interference that would be caused by new and very close housing or industrial developments. The high sensitivity of radio observations depends on our ability to detect minute differences in radio emission from different directions or at different times. Man-made radio interference changes the received power levels in an erratic way and obliterates these differences, decreasing the sensitivity or making it impossible to detect the wanted celestial signals. Some observations (e.g. pulsar

searches) aim to detect regular pulsed emissions or even rare and sporadic signals. It is clear that close interference sources have a much greater impact than more distant ones. Radio astronomers are of course aware of the growing demand for land for such developments as well as increased use of all parts of the radio spectrum. There are many sources of radio interference and it is a complex and difficult task to contain it so that radio astronomy stays viable.

Radio astronomers work closely in partnership with experts from planning authorities, spectrum regulators and industry to devise and implement schemes for the protection of radio astronomical observations that will at the same time minimise the restrictions on other activities. A lot of electrical and communication equipment is uncontrolled in its deployment (most consumer equipment, license exempt radio equipment) but creates low levels of unwanted radio emissions. These are in most cases unproblematic for the use of common radio and communications equipment, but not for very sensitive receiving installations such as radio astronomy observatories or radar stations. Compatibility studies are carried out in order to determine the impact of such equipment on sensitive installations and consequently the appropriate measures (shielding, separation etc.) for the protection of the installation. In the simplest case, one estimates the typical emission level of a particular source of interference, compares that to the standardised protection thresholds (given e.g. by the ITU-R Rec. 769-2) and determines the required shielding or minimum coupling loss (MCL). Using again standardised radio propagation estimates (e.g. ITU-R. P. 452-12) one may determine a minimum separation of the interferer from the radio telescope or in a more sophisticated approach designate complex exclusion areas which depend on the local terrain profile. Our institute is involved in planning procedures for wind turbines which create industrial radio interference. Here a similar procedure as above is used and found acceptable by the experts from BNetzA, the national regulating authority for Germany, the planning committees of local and regional councils and applicants who want to erect wind turbines on particular sites.

Another example is the ECC Decision (04)10 where as a result of such studies, some equipment like car collision avoidance radars has to be equipped with a mechanism for automatic deactivation close to radio observatories. Other, mass produced equipment cannot however be directly controlled in this way and will create severe radio interference if it gets too close to the telescope. The only option to protect a radio observatory from the effects of legal but interfering equipment is to enforce appropriate planning restrictions which make it unlikely that such equipment will be operated close to a sensitive site, e.g. a radio telescope.

Other countries have established radio quite zones around their radio observatories. In Europe this is not feasible because of our high population densities. We therefore see the implementation of prudent planning restrictions by the regulator and local authorities as the only viable way of protecting the European radio observatories from the radio interference that is created by the ubiquitous consumer equipment that invariably contains high frequency components. As a result we would like to express our support for the planning restrictions that are set out in the local planning policy of Cheshire East and Cheshire West and Chester in order to protect the viability of the Jodrell Bank radio observatory.

Sincerely,

Prof. Dr. J. Anton Zensus RadioNet Coordinator