Volume 26, No. 3 Summer 2016

ION GNSS+ 2016 TUTORIAL ION’S MILITARY DIVISION HOSTS JNC 2016 Google’s JNC Presenters Lay Out Android OS Progress and Proposals By Dee Ann Divis to Provide Courtesy of Inside GNSS Raw GNSS www.insideGNSS.com Measurements he Institute of Nav- Tigation Military ater this year, Google is going to Division’s Joint Naviga- Lenable the Android operating system tion Conference (JNC) (OS) to provide GNSS raw measure- is the largest U.S. ments with which mobile smartphone military Positioning, and tablet users can access pseudoranges, Navigation and Tim- Dopplers, and carrier phase data . . . and ing (PNT) conference Google is bringing that capability to an of the year with joint ION GNSS+ 2016 tutorial this fall. service and government On the afternoon of Tuesday, Septem- participation. ber 13, Dr. Frank van Diggelen, prin- This year’s four-day, cipal engineer in the Android Location for official use only & Content Group, and Steve Malkos, (FOUO) and classified event, opened Volunteer Dr. Mikel Miller in a partial set of the gear someone on patrol might carry. He the group’s technical program manager, June 6 in historic Dayton, Ohio, and fo- tried to keep pace with Capt. Krista Miller, will teach a tutorial at which attendees cused on technical advances in PNT with while the speaker, Kevin Coggins, described can learn to access and use these raw emphasis on joint development, test, military GPS receiver developments. measurements. and support of affordable PNT systems, GOOGLE ANDROID OS continued on page 7 logistics, and integration. The technical a number of conference presenters wove program was led by program chair Neeraj bits of history into their talks, in particu- Pujara, Air Force Research Laboratory, lar a tutorial on the evolution of military ...... INSIDE ...... Sensors Directorate, and co-chaired by aircraft navigation. The first-day tutorials, Greg Graham, U.S. Army. anchored as in years past by a session on President’s Report ...... 2 Sessions ranged from M-code encryp- PNT fundamentals, looked at combining CSNC 2016 ...... 3 tion and GPS modernization to anti- different sources of navigation, inertial Historian ...... 10 jamming techniques and a new proposal sensors and using cold-atom physics to Defense Matters ...... 13 for GNSS monitoring. From an opera- improve PNT accuracy. The Hughes Navigation Standards ...... 14 tional perspective the conference focused Design Group’s Ken Goussak, the naviga- on advances in battlefield applications of tion warfare technical lead at the GPS Di- RIN Medal Winner ...... 16 GPS, critical strengths and weaknesses of rectorate, walked a room full of attendees Section News ...... 17 field navigation devices, warfighter PNT through the structure of the cryptography SMS – Short Message Service . . . 18 requirements and solutions, and naviga- protecting M-code users. GNSS Program Updates . . . . . 20 tion warfare. Many of the sessions presented initial Calendar ...... 21 Perhaps inspired by the city that data and ideas for future research. A pre- housed the nation’s first airplane factory, JNC 2016 Recap continued on page 4

The Institute of Navigation • 8551 Rixlew Lane, Suite 360 • Manassas, Virginia 20109 FROM THE ION PRESIDENT, DR. DOROTA GREJNER-BRZEZINSKA A Successful JNC 2016, More Meetings Ahead

y most sincere congratulations go to the ION’s Meeting News MMilitary Division, its leaders, and government The ION is now accepting abstracts for the ION’s liaisons on a successful Joint Navigation Conference co-located International Technical Meeting (ITM) (JNC) this past June. The JNC took place June 6–9, and Precise Time and Timing Interval (PTTI) meet- in Dayton, Ohio, and more than 600 DoD person- ings, being held January 30–February 2 in Monterey, nel and related contractors attended the event; this California. See and for a list of technical sessions and abstract submission instructions. The ION’s Annual Awards will be presented during this event, and the 2017 ION Fellows will be named. The Executive Committee approved a proposal this past April to ensure that the ION’s ITM and PTTI meetings would continue to remain co-located for two more years, deciding to co-locate both events in the greater Washington, D.C., area in Janu- ary 2018 and January 2019. Besides the networking and multi-program advantages of holding the two meetings at the same place and time, co-location allows for more economical registration fees, and it was noted that many attendees would be able to make travel to Washington, D.C., a multi- purpose activity. Enjoy the rest of your summer, and see you all in September at ION GNSS+ 2016! Those of you unable to join us in Septem- Attendance General attendance was not the only increase, as ber – I invite you to follow us on Facebook and Twit- at JNC 2016 the exhibit hall grew by 40% over the prior year, ter at @ionavigation. increased 26% too. So, attendees had ample opportunity to experi- over last year! ence all the new technologies available to the DoD user community. See pages 1, 4-6 for more detailed information.

Award Nomination Reminder As president, and a long-time ION member, I Follow us on Facebook and Twitter regularly witness how the Institute benefits from at ionavigation. the talents and dedication of many ION mem- bers. Please take time this fall to acknowledge the contributions of your professional associates, and nominate them for an ION award that recognizes individuals making significant contributions or demonstrating outstanding performance relating to the art and science of positioning, navigation and timing. Please submit your nominations for ION’s Fellows and Annual Awards at www.ion.org/awards by October 15.

ION Newsletter 2 Summer 2016 CSNC 2016 ION Satellite Division Hosts a Panel Discussion at CSNC 2016 The Purpose of the ION® Founded in 1945, The Institute of Navigation is the world’s premier non-profit professional society dedicated to the advancement of the art and science of positioning, navigation and timing. 2016 Executive Committee President: Dr. Dorota Grejner-Brzezinska

Members of the joint ION/CSNC panel held at the 7th China Satellite Navigation Conference Executive Vice President: held in Changsha, China, earlier this year.: From left: Bin Zhao (Qualcomm), Eunsung Lee Dr. John Raquet (KARI, Korea), Pieter De Smet (EC), Dr. Rodrigo Leandro (Hemisphere GNSS/UniStrong), Dr. Jun Shen (UniStrong), China; Greg Turetzky (Intel), Kendall Ferguson (Hemisphere GNSS/ Treasurer: RTCM), Dr. Todd Walter (Stanford University), and David Turner (U.S. State Department). Dr. Frank van Graas Eastern Region Vice President: s it has several times in recent years, Lee, Korea Aerospace Research Institute Dr. Michael Veth Athe ION’s Satellite Division hosted (KARI), “GNSS Application Require- Western Region Vice President: a U.S. panel at the 2016 China Satellite ments in Korea.” Mr. Greg Turetzky Navigation Conference (CSNC) held in The session was well attended by both Satellite Division Chair: Changsha, China, May 18–20. The panel international participants at the confer- Dr. John Betz was co-chaired by Greg Turetzky, Intel Cor- ence as well as many local Chinese GNSS Military Division Chair: poration and ION Western Region Vice experts. The papers focused on the chang- Mr. Jan Anszperger President and Satellite Division member, ing world that the multi-GNSS reality Immediate Past President: Dr. Jun Shen (Beijing UniStrong Science has created now that all four constella- Ms. Patricia Doherty and Technology Co. Ltd.), and Xingqun tions have commercial applications. How to Reach the ION® Zhan (Shanghai Jiaotong University). Speakers presented various perspectives The joint ION-CSNC panel was held of GNSS applications in the areas of avia- Telephone: 703-366-2723 May 18 in the afternoon of the first day tion, survey and consumer as well as dif- Facsimile: 703-366-2724 of the event in Changsha, China. Panel ferent viewpoints from around the world. Web site: http://www.ion.org members and their papers topics were: The panel generated a lot of discussion E-mail: [email protected] David Turner, U.S. State Department, from the audience about how the various ® “U.S. Space-Based PNT Cooperation in constellations would interact and what The ION National Office the Era of Multi-Constellation GNSS”; differences the end users would see from 8551 Rixlew Lane, Suite 360 Greg Turetzky, “MultiGNSS impact and the multi-GNSS capability. Manassas, VA 20109 Opportunity in Emerging Markets”; This was the fourth time a joint panel The ION® National Office Staff Rodrigo Leandro and Kendall Ferguson, with ION was held at CSNC, and we Executive Director: Lisa Beaty Hemisphere GNSS, “ChinaCM/Atlas hope this tradition will continue and – An Innovative and Disruptive GNSS expand to other conferences worldwide. Director of Information Technology: Global Correction Service”; Kendall Similar sessions will be held in ION Rick Buongiovanni Ferguson, Hemisphere GNSS/RTCM, GNSS+ 2016 in Portland Oregon, and Director of Membership & Marketing: “The State and Status: Special Committee in ION Pacific PNT Conference 2017 in Kenneth P. Esthus – 104”; Todd Walter, Stanford University, Honolulu, Hawaii. Program/Author Liaison/ “Multi-Constellation GNSS for Avia- Any ION members interested in par- Executive Assistant: Miriam Lewis tion”; Bin Zao, Qualcomm, “Qualcomm ticipating in next year’s panel and present Meeting Planner: Megan Andrews MultiGNSS Strategy for Mobile Devic- to the technical navigation community Graphic Designer: Gwen Rhoads es”; Pieter De Smet, European Commis- in China, please contact Greg Turetzky sion, “GNSS Application Requirements or Jun Shen Newsletter Editor: Glen Gibbons in Europe and Worldwide”; and Eunsung . ION

Summer 2016 3 ION Newsletter JNC 2016 RECAP

JNC 2016 Recap continued from page 1 9/11, NORTHCOM supports agencies including the Department of Homeland Security and can be called upon to help in an emergency. After Hurricane Sandy, for example, NORTHCOM provided support to drain flooded subways and tunnels and helped get the power grid back up and running. NORTHCOM

coordinates with America’s neighbors, including working with Canada through the North American Aerospace Defense Command. Navy Captain Marc Eckardt, the su- perintendent at the U.S. Naval Observa- More than 600 DoD personnel and related contractors attended the JNC 2016 event in Plenary: The Foundation tory and the manager for the Defense Dayton, Ohio. for Military Ops Department’s Precise Time and Time The plenary speakers, addressing the Interval (PTTI) and the Celestial Refer- sentation by Sarah Law of Raytheon and conference theme of “Military Naviga- ence Frame (CRF), described how time Jabari Loving of Infinity Systems Engi- tion Technology: The Foundation for was once distributed by telegraph. Now, neering suggested that the Next Genera- Military Ops,” focused on users and new with GPS, precise time is distributed tion Operational Control System (GPS developments. worldwide at accuracies of 10 nanosec- OCX), after it is operational, could be Brig. Gen. Ronald Buckley, U.S. Air onds with respect to UTC. expanded to provide integrity monitoring Force deputy director of operations for Harold (Stormy) Martin, director of the for non-GPS satellite navigation constel- the United States Northern Command, National Coordination Office for Space- lations. Wilbur Myrick of ENSCO, Inc., spoke about how PNT is integral to based PNT, described the work under- described how a $20 software defined his organization’s role in protecting the way at the NCO to protect GPS could be used as the foundation for domestic front including from missile, an inexpensive spoofing detector. drone and cyber attacks. Created after Continued on page 6 Although often viewed as an interfer- ence source for GPS users, two presenta- Thanks to JNC 2016 Meeting Committee tions on pseudolites by Amelia Fortmayer of the Army outlined how employing pulse slots could enable the concurrent op- eration of GPS and a powerful pseudolite system without jamming the GPS signal. Other talks covered a wide variety of sub- jects, including new satellite technology and signal authentication as well as open architecture and timing accuracy. Other experts, including representatives from the companies with military GPS user equip- ment (MGUE) contracts, discussed the The Institute would like to thank all Military Division Officers and Government Liaisons that progress being made on MGUE, including organized and executed the JNC. Back Row: Dr. Mikel Miller, Kevin Coggins, Paul Olson, the capabilities of the new devices and the John Del Colliano, Dr. Tom Powell and Elliott Kaplan. Front Row: Jan Anszperger, Greg Graham, Neeraj Pujara, Sharon Donald, Eddy Emile and Bill Bollwerk. Not Pictured: Robert challenges of integrating them across the Greenlee, James Doherty, Don Jewell, John Langer and Jalal Mapar entire defense enterprise.

ION Newsletter 4 Summer 2016 JNC 2016 RECAP

JNC 2016 Exhibitors Acutronic USA Inc. Air Force Research Laboratory Autonomy and Navigation Technology Center/ AFIT BAE Systems Brandywine Communications CAST Navigation Cobham Antenna Systems Davenport Aviation, Inc. EMCORE Corporation Fibernetics LLC GPS Source, Inc. Harris Ideal Aerosmith iX Blue, Inc. Kearfott Corporation KVH Industries, Inc. L-3 Interstate Electronics LinQuest Corporation Mayflower Communications Company, Inc. Microsemi Frequency and Time Corp. Northrop Grumman NovAtel, Inc. Overlook Systems Technologies, Inc. Pretalen Raytheon Rockwell Collins Rohde & Schwarz USA Sensonor AS Spectracom Spirent Federal Systems Systron Donner Inertial Technology Advancement Group, Inc. (TAG) The Boeing Company The Institute of Navigation TRX Systems, Inc. VectorNav Technologies, LLC

Summer 2016 5 ION Newsletter JNC 2016 RECAP

spectrum, address the jamming of PNT Kevin Coggins, who is leading receiver signals, and develop requirements for development for the U.S. Army, under- a GPS backup to protect GPS users in scored the need for lightening the load the United States if the system were that warfighters carry by having a volun- compromised. teer strap on a substantial, if still partial, Col. Gerry Gleckel, Jr., the deputy set of the gear someone on patrol might director at the GPS Directorate described carry and try to keep pace with a leader progress on programs to modernize GPS moving briskly around the room’s perim- space and ground segments, including eter. He detailed the Army’s architecture new and still-unfunded proposals for and need for affordability, wrapping up protecting warfighters relying on the well before his two demonstrators threw ION Col. Gerry Gleckel, Jr. GPS signal. in the towel.

An overhead interior view of the fourth building at the National Museum of the United States Air Force. The fourth building includes more than 70 aircraft in four new galleries — Presidential, Research & Development, Space and Global Reach. U.S. Air Force photo by Ken LaRock

Air Force Museum Opening Attracts JNC Attendees he Joint Navigation Conference Foundation, will house four galleries — building will be the VC-137C Air Force Tcoincided with the formal opening Presidential, Research and Development, One (SAM 26000), which was used by of the fourth building at the National Space and Global Reach, along with three eight presidents - Kennedy, Johnson, science, technology, engineering and Nixon, Ford, Carter, Reagan, George H.W. Museum of the U.S. Air Force located at mathematics (STEM) Learning Nodes. Bush and Clinton; the only remaining nearby Wright-Patterson Air Force Base, During the official grand opening XB-70 Valkyrie; the C-141C Hanoi Taxi, an event that attracted a number of JNC ceremony on June 7, Secretary of the Air which airlifted the first American prisoners attendees Wednesday night for a ribbon Force Deborah Lee James said the stories of war out of North Vietnam in February cutting ceremony. that will be told in these four galleries 1973; the Space Shuttle Exhibit featuring The new $40.8 million, 224,000 square feature fascinating and important aspects NASA’s first Crew Compartment Trainer; foot fourth building, which was privately of the Air Force mission. and a massive Titan IVB space launch financed by the Air Force Museum Among the stories found in the fourth vehicle that weighs 96 tons.

ION Newsletter 6 Summer 2016 GOOGLE ANDROID OS

GOOGLE ANDROID OS continued from page 1 • The Android Software Stack — how PDF at . Diggelen and that Google will launch later this year. tion about the definitions of the dif- What partici- Steve Malkos Then next year new Android handsets ferent data structures and learn which pants want from this will teach a will start to support it, as it will become of these is available at the Application tutorial (e.g., get raw a mandatory feature in Android, accord- layer. At the end of this section, the measurements from a tutorial about ing to Steve Malkos technical program tutorial leaders will provide Android N phone/tablet, analyze a new Google manager in Google’s Android Location phones that attendees can use for the raw measurements, Android OS. and Context Group. Application develop- rest of the class. compute position ers will be the primary beneficiaries of the • Using the data. After a break to col- from pseudoranges myself, fuse measure- new Android OS feature. lect GNSS and MEMS data outside, ments from GNSS and other sensors, The ION GNSS+ tutorial will instruct tutorial participants will download the understand Android, software tools for participants about how to access and use data from the phones and do some processing measurements, and so forth); data from the GNSS chips and inertial basic data processing, using software data of interest (pseudoranges, pseudo- and accelerometer microelectrome- tools that will also be available follow- range rates, i.e., Doppler; accumulated chanical (MEMS) sensors inside Android ing the class. Finally, Malkos and van Delta range, i.e., carrier; carrier to noise smartphones and tablets. This tutorial is Diggelen will give specific examples of density ratio, nav data, e.g., satellite orbit open only to ION-GNSS+ attendees. To research projects and applications to and clock; and/or MEMS sensor data. register for the conference, visit . and knowledge obtained in the class. types of GNSS and regional and augmen- The class comprises three parts: People who sign up for the tuto- tation satellites of interest that attendees • Description of available data that is rial can also help tailor it to their own are interested in. accessible by developers in Android. needs, by filling out an online survey Google location-related talks from the This is the theoretical part of the class form and letting Google know what Android Location and Context Team can and will review the definitions of the they would like to have covered in the be found on YouTube, including “Mak- different types of data, their physical class. The link can be found in the ing Android Sensors and Location Work meaning, and how to use them for description of the tutorial in the ION for You,” from the Google developers navigation. GNSS+ 2016 program, a downloadable conference, I/O 2016. ION

Summer 2016 7 ION Newsletter 2016–18 SATELLITE DIVISION NOMINATIONS & VOTING he Satellite Division Nominating Committee, chaired by All additional nominees must fulfill nomination requirements TDr. Jade Morton, has submitted the following nomina- as indicated in the ION Satellite Division Bylaws and the tions for Satellite Division Officers: nomination must be received at the ION National Office by Chair: July 13, 2016. Dr. Frank van Diggelen, Google Online voting for the ION Satellite Division Officers will be Vice Chair: available after July 16. Completed ballots must be received at Ms. Patricia Doherty, Boston College the ION office by August 8, 2016 in order to be counted. Dr. Chris Hegarty, The MITRE Corporation Election results will be Secretary: announced during the 29th Ms. Sandra Kennedy, NovAtel, Canada International Technical Meeting Mr. Gregory Turetzky, Intel Corporation of the ION Satellite Division be- Treasurer: ing held September 12-16, 2016 Dr. Jason Rife, Tufts University in Portland, Oregon. The newly Dr. Sanjeev Gunawardena, Air Force Institute elected officers will take office of Technology on September 16, 2016 at the Pursuant to Article IV of The Institute of conclusion of the meeting and Navigation Satellite Division Bylaws, “Addition- will serve for two years. Election al nominations may be made by petition signed results will be reported in the by at least 25 members entitled to vote for the ION Newsletter. ION office for which the candidate is nominated.” © iStockphoto.com/Kuo Chun Hung © iStockphoto.com/Kuo

January 30 - February 2, 2017 Hyatt Regency Monterey Monterey, California

ITM International Technical Meeting

Precise Time and Time Interval PTTISystems Appplications Meeting

Co-located 2017 International Technical Meeting (ITM) and Precise Time and Time Interval (PTTI) Systems and Applications Meeting ONE Registration Fee, TWO Technical Events and a Commercial Exhibit www.ion.org

ION Newsletter 8 Summer 2016 Nominate a Colleague for ION Fellows and Annual Awards

Nominations for The Institute of Navigation’s (ION) Fellows and Annual Awards Program are now being accepted. The ION Annual Awards Program is sponsored by The Institute of Navigation and recognizes individuals making significant contributions or demonstrating outstanding performance relating to the art and science of navigation. The Institute accepts nominations for the following annual awards:

Early Achievement Award Tycho Brahe Award recognizing an individual early in his or her career who has made an recognizing outstanding contributions to the science of space outstanding achievement in the art and science of navigation. navigation. Superior Achievement Award Norman P. Hays Award recognizing individuals who are practicing navigators and have made recognizing outstanding encouragement, inspiration and support outstanding contributions to the advancement of navigation. contributing to the advancement of navigation. Distinguished PTTI Service Award Colonel Thomas L. Thurlow Award recognizing outstanding contributions related to the management of recognizing outstanding contributions to the science of navigation. PTTI systems. Captain P.V.H. Weems Award recognizing contributions to the art and science of navigation.

Election to Fellow membership recognizes the distinguished contribution of ION members to the advancement of the technology, management, practice and teaching of the arts and sciences of navigation, and/or for lifetime contributions to the Institute.

Submit your nominations today for ION’s Fellows and Annual Awards at www.ion.org/awards. All nominations must conform to ION nomination guidelines. Details of the nomination process and forms are available at www.ion.org/awards. Nominations must be received in proper form by October 15th to be considered. FROM THE ION HISTORIAN, MARVIN MAY Tidal Analysis and Prediction Part III : The Shape of the Earth

This is the third of a series of three articles on the history Eighteen hundred years after Hipparchos, Newton of tidal analysis and prediction. The first two articles argued that as a consequence of its rotation, Earth chronicled man’s gradual understanding of the complex should have an oblate ellipsoidal shape, flattened at phenomena that govern the rise and fall of the Earth’s the poles and bulging at the equator. He showed oceans, rivers and estuaries. This article focusses on the that variations in gravity indicated by the pendulum same phenomena’s effects on the Earth’s shape, composi- observations made at different latitudes could be ex- Marvin B. May tion and rotation. plained by allowing for the equatorial bulge produced by the Earth’s rotation. hen Isaac Newton published his 1687 treatise He deduced that Earth is a flattened, oblate Wthat explained the fundmental law of gravita- spheroid, with a radius about 17 miles greater at the tion, the breaktrough opened up a floodgate of sub- equator than at the poles. He the flattening at 1/230. sequent discoveries in geodesy, geology, astronomy, Flattening is the ratio of the difference between the horology, and meteorology as well as navigation. major (equatorial) and minor (polar) axes of an ellipse to the major axis. Lunar-Solar Precession Remarkably, Newton further showed that preces- Earth’s precession, historically called the precession sion is a consequence of the Moon’s and Sun’s gravita- International Earth of the equinoxes, is a phenomenon first observed by tion acting on the inclined Earth’s equatorial bulge. Rotation Services the Greek astronomer Hipparchos in the 2nd century Newton’s theory that the Earth was flattened at the logo BCE. He created the first extensive star catalogue and poles was highly controversial for the next 50 years, by comparing some of the star coordinates with those An arc of meridian was first measured by French determined over a century earlier, found a systematic astronomer and priest Jean Picard in 1669. He was Engraving of Pierre decrease of the ecliptic longitudes of the stars. the first person to measure the size of the Earth with de Maupertius wearing Lap cloth- Hipparchos reasoned that the equator was not some accuracy. (Attention Star Trek fans: he is one of ing pointing to the stable in inertial space but moved in such a way that the inspirations for Jean-Luc Picard, captain of The "Carte de l'arc du Meridien mesuré the celestial pole traced out a circle around the eclip- Enterprise) au Cercle Polaire) tic pole. Based on a comparison with prior celestial Picard’s contemporary Giovanni-Dominique Cassi- observations 148 years ni was the founding director of the Paris Observatory. earlier, Hipparchos es- He was also the first to observe Saturn’s four moons timated a precession of and discovered the gap in that planet’s ring system — 2 degrees in 148 years the Cassini Divison — and developed the Cassinian or a precessional period curve theory. (The international Mission to Saturn of 26,640 years. that launched in 1997 is named after him.) He also

The original academicians measured meridian arcs in 1712 and concluded that at the founding of the Earth is a prolate spheroid. Royal Academy of Based on these measurements, Cassini and his Science in Paris are presented to Louis XIV in astronomer son Jacques concluded that the shape of 1667 (Henri Testilin) the Earth is a prolate spheroid-elongated at the poles — not the oblate spheroid previously deduced by Newton and Dutch astronomer Christiaan Huygens, who had studied the shape of Saturn’s rings.

Earth viewed from the moon (NASA)

ION Newsletter 10 Summer 2016 ION HISTORIAN

The French Geodesic Mission Bradley had made repeated observations The controversy arising from these dif- of the declinations of stars during the 20 ferent theories stimulated a remarkable years between 1728 and 1748. expedition, the French Geodesic Mission His observations revealed a periodic of 1736 that set out to find out if the oscillation of the declinations, the period Earth was an oblate or prolate spheroid. being 18.5 years, the amplitude 9 arcsec- Determining the Earth’s ellipticity was onds, and the phase depending on the right a challenging issue 280 years ago. (Con- ascension of the star. This nutation could sider that if the Earth were a globe with a be visualized as the true pole of the celestial a 12-inch equatorial diameter, the polar sphere moving in a little circle, the nutation diameter would be about 11.96 inches, or circle of radius 9 arcseconds with a period only 0.04 inches smaller.) equal to that of the nodes of the Moon’s Cover of Charles Marie de La Condamine's book In 1735, Pierre de Maupertius), the orbit, 18.6 years, around a mean pole. This on the French Geo- Director of the French Academy of Sci- mean pole, in turn, moved in the large desic Mission to Peru ences, who earlier introduced Newton’s precession circle amplitude 23.5 degrees (Ecuador) theory of gravitation to France, showed with the period of 25,800 years around the The young George Darwin that the axes of an Earth ellipsoid of revo- pole of the ecliptic. (Cambridge University) lution can be calculated from lengths of a The eminent mathematicians of the degree of latitude obtained by meridian- late 18th century refined the observed arc measurements. precession-nutation phenomena. Lumi- “These results seem to present evidence Based on this formulation, the Paris naries including Jean le Rond d’Alembert of a tidal yielding of the Earth’s mass, Academy sent organized the expedition (who coedited Diderot’s encyclopedia); showing that it has an effective rigidity to the Territory of Quito in the South Leonhard Euler and Pierre de Laplace, about equal to that of steel.” American Andes (now Ecuador)to mea- great mathematicians of the 18th century, His discovery of Earth tides led to sure a length of arc at a low latitude, and all refined the theoretical understanding major observational and theoreticalefforts shortly thereafter sent another expedition of these phenomena. to determine whether the earth was solid to Kittisvaara Mountain in Pello, Lapland In Laplace’s groundbreaking Mécanique or had a liquid core. to measure it at a high latitude. Céleste he developed the hydraulic theory of This effort was based on what had al- The northern expedition, under DeM- tides, derived an extensive treatment of the ready been observed about precession-nu- aupertius, consisted of mathematicians theory of precession-nutation, and applied tation and theorized about polar motion and astronomers including Alexis Clai- Euler’s equations to show the central role Leonhard Euler, the major 18th century raut and Anders Celsius. and, within a played by the moment of inertia ratio re- mathematician, Astronomer Joseph La- year, theydemonstrated conclusively that flecting the flattening of the Earth ellipsoid. grange and Louis Poinsot, who invented the Newton’s deductions were correct. geometrical mechanics, provided the The Andes expedition included as- What’s Inside? mathematical basis that revealed that the tronomer Louis Godin, geodesist Pierre During the second half of the 19th instantaneous axis of rotation of the Earth Bouguer “the father of Naval architec- century, geodesists developed a number of is not fixed in position on the Earth, but ture” and geographer Charles Marie de La theories of what lies beneath Earth’s sur- actually moves relative to its crust. Condamine. They succeeded in measur- face. Was it fluid or solid, homogenous or This phenomena, related to the ing the Earth at the equator, helping to consisting of shells of different densities? precession-nutation of the axis of rotation define Earth’s shape, but they didn’t get The English physicist William Thom- of the Earth with respect to inertial space, home for 10 years. son, Lord Kelvin,thought it was elastic was a major research subject from the solid, deforming in response to Earth’s late 19th century through the mid–20th The Role of Nutation and Moon’s gravitational forces. century. Although Newton touched upon the But it was Charles Darwin’s son, Scientists who straddled both cen- existence of a small nutation— a periodic George, who became as important to the turies, including Americans Seth Carlo oscillation of the Earth’s axis that causes study of tides and lunar evolution as his Chandler, and Simon Newcomb Walter the precession of the poles to follow a father was to biology. He developed the Lambert; Britons Harold Jeffreys, Lord wavy rather than a circular path— it was theory of tidal friction mathematically Kelvin, Joseph Larmor), and Augustus the English Astronomer Royal James and published his results in 1882. In A Love, and German geodesist Friedrich Bradley who discovered and explained Numerical Estimate of the Rigidity of the Helmert all made major contributions to the principle nutation of the Earth. Earth he concludes: the complex interactions among preces-

Summer 2016 11 ION Newsletter ION HISTORIAN sion-nutation, tidal friction, polar motion They reasoned that the dynamic rela- our environment. These three articles and their implications on earth’s elasticity tionship between Earth and Moon contin- barely disturbed the surface of investiga- and liquid core composition. ually loses energy from tidal friction. One tions into tidal effects. It is a continuing It wasn’t until 1936, however, that part of this energy turns into potential fertile area of research in the geophysical, Danish seismologist Inge Lehmann, con- energy of the moon’s position relative to geodetic and astronomic communities firmed the true nature of Earth’s interior. the Earth, and the rest of the energy devel- with international coordination adminis- She used her observations of shock waves ops heat in the interior of the Earth. tered by the International Earth Rotation from a 1929 New Zealand earthquake to Tidal friction is responsible for the and Reference Systems Service: . ION of a solid inner core surrouned by a liquid per century in the length of a day and Other ION Historian articles related to outer core separated by areas of abrupt deceleration in the moon’s longitude of the shape of the Earth may be found in the change in seismic wave velocities (the 25 arcseconds per century. Tidal friction Summer and Fall 2001 Newsletters. Some “Lehmann Discontinuity.”) was found to play a fundamental role in information in this article was extracted the evolution of the Earth-Moon system from: Ekman, Martin, “A Concise History Tidal Friction and thus, the end of using Earth rotation of the Theories of Tides, Precession-Nuta- The concept of Earth tides opened as a time standard. tion and Polar Motion (From Antiquity up new prospects for the research on to 1950),” Surveys in Geophysics 14: tidal friction. Both George Darwin and International Earth Rotation Service 585-617, 1993 George Airy, English astronomers royal For millenia, mariners have needed to Marvin B. May is the chief scientist of the in the mid–19th century, showed that understand tides to survive. Today, the Pennslyvania State University’s Applied Re- tidal friction will not only retard the study of gravity waves, while based on search Laboratory’s Navigation Research and Earth’s rotation, but also cause the moon Einteinian, not Newtonian, gravitational Development Center in Warminster, Pennsyl- to recede from the Earth. theory, is still vital for understanding vania. His email is Pacific May 1–4, 2017 Marriott Waikiki Beach, Honolulu, Hawaii

PNT Where East Meets West in the Global Cooperative Development of Positioning, Navigation and Timing 2017 Technology www.ion.org/pnt

ION Newsletter 12 Summer 2016 Defense Matters PNT Smoke and Fog

ere in the Washington, D.C., area the recent inherent in reliance on a single source of radionavi- H4th of July celebration was dampened by fog, gation information that were at the end of the path low clouds, and a misty rain. If you tuned into the being charted to reduce government costs. The resulting live PBS broadcast “A Capital Fourth,” however, you The Federal Government was resolute in its drive growth in would have been surprised to see the Capitol without toward reducing the number of federally provided any scaffolding and a fireworks display bursting in a radionavigation systems, while at the same time, the both numbers clear night sky. commercial market place exploded with the dramatic of users and This remarkable phenomenon didn’t occur through evolution of GPS-enabled technology since GPS types of a miracle of meteorology or technology but rather became available in the early 1990s. applications from decisions by PBS to use archived footage of past The resulting growth in both numbers of users and for positioning, shows in order to provide “the best possible televi- types of applications for positioning, navigation, and navigation, sion viewing experience.” PBS eventually apologized timing (PNT) has exceeded anything ever envisioned and timing for their broadcast, and an unnamed commenter in the early years of the FRP. Further, that growth provided the perspective, “Only in D.C. could a PBS exacerbated the potential impact of any vulnerability (PNT) has . . . show become a scandal.” associated with GPS overreliance, which resulted exacerbated Building on the thought that Washington can from the susceptibility of space-based PNT signals the potential simultaneously be a source of clarity and of smoke to jamming and interference. Now fast-forward to impact of any and fog, one can appreciate a perspective in which the fall of 2014, when a national awareness began to vulnerability archived historical material provides a clearer picture emerge that the government should address the need associated of the world than that which is currently before us. to expand the available sources of PNT information A case in point is the Federal Radionavigation in the event there is a disruption to GPS. with GPS Plan (FRP). The first edition of the FRP was released That growing awareness seemed to result in a overreliance. in 1980 as part of a Presidential report to Congress, clearer vision within the government of a way ahead responding to the International Maritime Satellite centered on formation of the National Space-Based (INMARSAT) Act of 1978. This marked the first PNT Executive Committee’s Complementary PNT time that a joint Department of Transportation/De- Tiger Team, chartered to explore the possible rekin- partment of Defense plan was produced for federally dling of a national enhanced Loran (eLoran) capabil- provided, common-use systems serving both civil and ity (originally noted in the 1988 FRP). military sectors. Clearly the ability to field an effective and afford- By 1988, when the fifth edition of the FRP was able backup to approach the capabilities provided by released, the clarity of the federal plan to provide GPS is a challenging task. However, the activities and these common-use systems began to diminish as the initial recommendations from the Tiger Team in 2015 promise of GPS became more real. The Background appeared to provide a vision of clarity by placing the Section in the 1988 Plan states (Section 1.1): “Since government on a path toward the best-fit backup so- the publication of the first edition of the FRP there have lution presented by a reinvigorated nationwide eLoran been significant changes in the radionavigation environ- capability, first for timing and later for positioning. ment. Although the Global Positioning System (GPS) Now, despite those encouraging promises, reports is a principal driving force in the FRP, other external from the most recent National PNT EXCOM meet- factors such as breakthroughs in low cost Long Range ing indicated that the goal of establishing the initial Navigation (Loran-C) receiver technology, marketplace timing backup for GPS has been complicated by the pressures, delays in the space program, and increasing internally imposed need to first establish the require- private sector involvement have affected the evolution of ments for such a backup timing capability. (See the ar- Doug Taggart the FRP.” Later in the same section is the statement; ticle, . That President “The need to consolidate and reduce the number of process has reportedly begun and is currently planned Overlook systems is a major objective of DoD and DOT.” to produce the necessary requirements by late 2017. Systems With the benefit of 20/20 hindsight, the reference As of this moment, we can hope that the require- Technologies, Inc. to “changes in the radionavigation environment” and ments effort will provide the clarity necessary to the “evolution of the FRP” as characterized in the 1988 proceed through the smoke and fog in order to timeframe failed to appreciate the vulnerabilities implement the needed backup capability. ION

Summer 2016 13 ION Newsletter NAVIGATION STANDARDS

directions, but likewise affected by the Send Measurements, same constraints. Some had titles exhibit- ing concern (e.g., “Unfinished Business Not Coordinates — Glaring Absences from the Achieve- Jim Farrell ment List” (PLANS2004), or a Fall 1999 ig pow-wow brewing: a Geodesicx/ change it, and make chicken soup from NAVIGATION paper with the same title BUrsaNav/Overlook/SAE/ION work- these here chicken feathers. as this article, or from ION GPS 1990 ing group for navigation standards. Why Call it an integrated system. Give it the “That All-Important Interface.” is this man smiling? Because updated price tag of an integrated system. Will it BE With multiple printed manuscripts standards hold a key for an integrated system? Well, 2 out of 3 . . . . came appearances in various forums (e.g., extinguishing many long- My NAECON 1977 presentation, the Airlines Electronic Engineering Com- standing obstacles. mindful of irreversible degradations mittee, RTCA Inc. SC-186) plus Federal Present standards, from (delays, timing uncertainties, nonlinear Aviation Administration meetings. Still, pre-historic (OK, maybe transformation, word length truncation, this wasn’t “me-against-the-world” (pre- only medieval) times, restrain “massaging with Kentucky windage”) and sumably the world wins that battle if I’m designers. Want to combine multiple data acting on data ahead of sensor interfaces, foolhardy enough to fight it); the last two sources? OK, just use this embedded sys- stated that they “will presumably be cor- ION manuscripts just cited had highly tem. What, you want flexibility for future rected with progressing assimilation of ad- qualified coauthors. modification? Oh, yeah, you’d have to buy vanced methods into operational systems.” So, there were significant items on a whole new system. A later (1993) NAECON presenta- the plus side for integrated navigation Instead then, combine their outputs tion (“System Integration: Performance standards. What about negative? Actu- in a central processing algorithm. What, Doesn’t Measure UP”) noted, um, we’re ally the primary resistance wasn’t from those outputs can’t access vital data? Just a tad late. The issue reappeared in several defenders of the STATUS QUO (that’s take what’s there anyway. Fix it but don’t subsequent publications focused in other Latin for “the mess we have now”). A

08 – 10 November 2016 University of Strathclyde, Glasgow, UK

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The International Navigation Conference series has a strong Themes for INC 2016: track record in attracting the best, most knowledgeable speakers from around the world. INC 2016 will feature the hottest topics • Emerging Science • Multisensor PNT at the cutting edge of navigation technology and development, • Modern Markets • Navigation Now and will be held at the University of Strathclyde, Glasgow, UK. • Modern Threats

For more information and how to submit an abstract visit: www.internationalnavigationconference.org.uk or Contact Conference Manager: Sally-Anne Cooke on ROYAL INSTITUTE OF NAVIGATION (+44) 20 7 591 3135 [email protected]

ION Newsletter 14 Summer 2016 NAVIGATION STANDARDS bigger obstacle was complacency. With GPS World, into adding to the magazine’s and/or angles and/or their rates. Integra- GPS making life so easy for so many for annual GPS receiver survey an extra single tion worthy of the name. Thank God, it’s so long, oversimplified methods became column with two entries separated by a coming. ingrained. Need a fix? Just update posi- slash “/”. The numbers represented RMS If you are interested in participating in the tion from GPS. Don’t need more. error, under the specified conditions, navigation standards working group or have But wait. What, that gives terrible for pseudorange and integrated Doppler questions about the navigation standards velocity accuracy? Well, GPS-provided 10 (carrier phase increment). A dash in that working group, please contact Bill Wood- meters/second satisfies ADS-B (Automatic column meant “data absent” or no com- ward, 1-757-312-0790, extension 217, Dependent Surveillance–Broadcast). mitment. The addition, appearing in one . ION What, that’s extremely dangerous for col- “Big Book of GPS” issue, revealed about lision avoidance, especially with air traffic 15% compliance. The other 85% settles growth? Well, there’s TCAS (Traffic Alert for recreational use (read, the “latitude-&- and Collision Avoidance System). What, longitude meter”). Corporate that causes passengers to scream, and So, fast forward to this year: Geodesicx/ we have an alternative, not four decades Bill Woodward, recently elected chair of Profile old, with flight-validated accuracy on the SAE’s Avionics Systems Division (ASD), Linear Photonics, L.L.C. order of a centimeter/second? Well, that’s to the rescue with an idea to get the GPS linphotonics.com/ nice but we do other things. Also we still manufacturers to make the individual sat- just average the coordinates from separate ellite measurements available for process- data sources. So, never mind. ing in user equipment. Together with the ION DC Chapter, Bill is putting together A Prolonged History of Avoidance a working group to develop navigation Why has concrete action taken so long? standards. Were my assertions too timid? Not guilty; We need measurements instead of repeatedly raising the topic of our industry’s coordinates, so that we can coordinate the problems requires tightrope walking. It has measurements — ALL measurements, not Linear Photonics, L.L.C. is a small business specializing in state of the to be done without throwing rocks, risking just GNSS. There’s more to this — much art microwave photonics design and misinterpretation, promoting extravagance, more. Past failure to act, over periods manufacturing for communications, posing as self-appointed oracle-in-chief, be- extending across decades, has greatly signal remoting and sensors. Our coming nominated for persona-non-grata/ restricted our ability to counteract crises facility supports both engineering and manufacturing and is conve- public-enemy-#1 or skunk-at-the-garden- that could materialize any time. niently located in the Princeton- party, etc. It’s tricky. Although ingrained Unlikely? Yes. Unlikely ENOUGH? Trenton corridor of New Jersey. habits allowed much opposition to be pas- No. In a brilliantly prescient presentation Our products cover frequency ranges from DC to beyond 50 sive “benign neglect,” resistance was visible (ION NTM plenary, 2001) John Beukers GHz, and integration levels that enough. Recommending departures from warned against widespread complacency include small hybrid laser and custom would require a strong enticement about GPS. Typically, it received skeptical photoreceiver modules to large scale multi-purpose systems that not yet in existence. responses from some accredited places. employ RF-, microwave-, and First the need had to be clearly ex- Autumn of that year brought powerful re- millimeterwave-over-fiber. plained. To the scientific community that affirmation from the Volpe report. Action Our applications include long part was easy; neither differential opera- has likewise been extremely slow. range fiber optic communications, antenna and radar signaling and re- tion nor integrity testing can be executed The Geodesicx/UrsaNav/Overlook/ moting, naval and avionics EW, test well without direct access to measure- SAE/ION navigation standards work- equipment, harsh environments, ments. If partial alternatives exist, relying ing group is crucial, for finally removing precise time and frequency distri- bution and broadband electronic on internal (therefore inscrutable as well long-standing, undue constraints. For sensors. as inflexible) means would, to many over a half-century we have known how Our facility incorporates the entire minds, be considered insufficient. ERGO: to combine intermittent partial data — of product life cycle process from microwave and optical component Receiver survey --front-and-center. different types at varying accuracies with research and development through About 15 years ago, Phil Ward and different sensitivities from different direc- production. Frank van Graas coached me on nailing tions at different times. For more information on corporate down conditions appropriate for judg- The door is opening for navigation membership in the Institute of ing the adequacy of GPS performance. I and surveillance to extract, in tandem, Navigation, please contact Kenneth P. Esthus at 703-366-2723 extension 1004 later talked Glen Gibbons, then editor of full benefits offered by observed distances

Summer 2016 15 ION Newsletter ROYAL INSTITUTE OF NAVIGATION

RIN Awards Dr. Terry Moore with New Honors rofessor Terry Moore, director of the the third Briton to receive an ION and international GNSS conferences PNottingham Geospatial Institute fellowship. and both national and international (NGI) at the University of Nottingham, He was promoted to the UK’s first professional and scientific bodies. received the J. E. D. Williams Medal on Chair of Satellite Navigation in 2001; he With a long and distinguished career July 19 for his significant and varied con- has completed numerous research projects devoted to teaching and research, Profes- tributions to the funded by industry, research councils, the sor Moore started at The University of Royal Institute European Space Agency and the Europe- Nottingham with a BSc in civil engineer- of Naviga- an Commission, and has supervised over ing followed by a Ph.D. in space geodesy. tion (UK), in 25 PhD students. Professor Moore is also a Fellow of the particular his Professor Moore has authored, or Chartered Institution of Civil Engineer- leading role in been a leading contributor to more than ing Surveyors, the Royal Astronomical staging its major 200 technical research papers published Society and an Associate Fellow of the conferences. in top journals. This is in addition to Remote Sensing and Photogrammetry The award being a major supporter of national Society. ION is the latest in a string of Parkinson's GPS Role Earns Marconi Prize RIN honors. In 2013, Professor Moore r. Bradford Parkinson, the original designated Marconi Fellows and expected received the Harold Spencer-Jones Gold Dmanager of the NAVSTAR GPS to pursue further creative work that will Medal — the highest honor the RIN development program and a Stanford add to the understanding and development bestows — for outstanding contribu- professor emeritus of aeronautics and of communications technology. The tions to navigation. He was also one of astronautics, will receive the 2016 Marconi Marconi Prize includes the honorarium and the youngest-ever recipients of the highly Prize at a November 2 banquet and a work of sculpture. esteemed award. award ceremony during the Previous recipients include Sir Stanford PNT Symposium. The Tim Berners-Lee, an inventor Professor Moore has also won the $100,000 prize, given annually, of the ; Sergey RIN’s Richey Medal for best paper to recognizes major advances in Brin, co-founder of Google, be published each year in the Journal of the field that benefit humanity. Inc.; and the late Arthur C. Navigation in 1999 and again in 2008. "Parkinson's contributions Clarke, writer of science fiction, He has now received more top medals to the development of GPS including 2001: A Space Odyssey. from the Royal Institute of Navigation helped create a vast global Vinton Cerf, the 1996 recipient (RIN), in its near 70-year history, than utility that provides positioning, of the Marconi Prize and a anyone else. navigation, and timing co-designer of the Internet (PNT) information to the world and is protocol suite TCP/IP for the Department His Royal Highness, The Prince Philip, a vital part of today's global information of Defense, will speak at this year's PNT Duke of Edinburgh, who is patron of the infrastructure," the wrote Symposium on the subject, "Benefit from a Royal Institute of Navigation, will present in a press release announcing the award. new Suite of Internet Protocols." the award to Professor Moore at the RIN This is far from the first honor for As Marconi Society Vice Chairman Annual General Meeting at the Royal Dr. Parkinson's contribution to GNSS Cerf noted about this year's award, Geographical Society in London. Moore engineering, policy, and practice. In "Today, there are billions of GPS receivers is currently vice-president of the institute. 2003 he shared the Draper Prize with in the world. GPS is one of the most Professor Moore is the European Ivan A. Getting for his contributions to under-rated advances in the history of development of the Global Positioning information science. It's taken for granted, Technical Advisor for the ION Satellite System. but Parkinson was on the ground floor Division and was the general chair of In 2004 he was inducted into the of enabling air, space and terrestrial the 2015 ION GNSS+ conference. In National Inventors Hall of Fame. In 2013 guidance and navigation with GPS. . . . 2013, he was awarded an ION fellow- Dr. Parkinson received the Technology Dr. Parkinson's achievements have been ship for his outstanding leadership of Prize of Germany's Eduard-Rhein- game-changing." the navigation community, the establish- Foundation and, along with other "GPS The Marconi Society was established ment of GRACE (GNSS Research and Originators," the Goddard Trophy in in 1974 through an endowment set up March 2012, awarded annually to the by Gioia Marconi Braga, daughter of Applications Centre of Excellence), the individual or group who has had the , the Nobel laureate who establishment of NGI, and sustained greatest impact on space activities. invented radio (wireless telegraphy). ION contributions to the advancement of Recipients of the Marconi Prize are navigation and GNSS. He is only

ION Newsletter 16 Summer 2016 ION News and Notes

NEW ENGLAND SECTION material and used a mixture of slides and DAYTON SECTION Dr. Keith McDonald, ION New props to communicate his message. The Members of the Dayton Section met England Section Chair, reported that material was very well received, with at the Wright-Patterson AFB Club and the New England ION Section met on a multitude of questions asked during Banquet Center on the evening of June Monday, May 16th. and after the presentation. It was noted 30 for their annual dinner. Attendees The meeting was the commonalities in message between enjoyed an extended social hour, the hosted by Draper Mr. Coggins message and the message traditional putting contest on the prac- and facilitated by presented at the last New England tice green behind the club and dinner. Rochelle Moore and section meeting from Dr. Mikel Miller Outgoing section chair Thomas Pestak Jan Anszperger of from AFRL; even though the presenters thanked this year's officers for their Draper. were from different military services. contributions and presided over the elec- Mr. Kevin Draper was kind enough to include tion of next year's slate. For the 2016- Coggins, Program refreshments and deal with security free of 2017 season, the selected officers are as Kevin Coggins Manager PNT for charge. During the refreshment period, follows: Major Scott Pierce, Chair; Mr. the U.S. Army, presented “A Vision attendees took time to network as well as Brian Roadruck, Vice Chair; Mr. Mark for Innovation in Military Positioning, learn from a variety of Draper technology Carroll, Executive Secretary; Mr. Boyd Navigation, and Timing Technologies” posters and engage with their respective Holsapple, Treasurer; Mr. George W. during which he provided relevant authors. Simons, Facilities Coordinator. ION Obituaries wo well-known personalities in the positioning, navigation, was that I always had new interests — I found the universe, great Tand timing community passed away recently: Dr. Gernot nature, truly fascinating. Life was a terrific adventure for which I M. R. Winkler and Dr. Lee Ott. am deeply grateful.” A physicist and an astronomer, Dr. Winkler served as the An native of Austria, Dr. Winkler received the Ph.D. degree Director of Time Service at the U.S. Naval Observatory (USNO) in physics and astronomy from the University of Graz, Austria. from 1966 to 1995. In 1969, Dr. Winkler and Clark Wardrip passed away on April 30. He was 93. organized the first Precise Time and Time Interval (PTTI) Systems Dr. Lee Ott, 73, who passed away peacefully at his Houston home Applications Meeting. In 1994 he received the on June 1, spent his entire career in the navigation field, including PTTI’s Distinguished Service Award. During Western Geophysical where he worked on the development of his time directing the Time Service he oversaw an integrated navigation system utilizing Doppler sonar, Transit development of the USNO’s Master Clock satellites, inertial platforms, and radio navigation systems. system. While still Western Geophysical, he later developed an An active member of the International integrated radio navigation system for the marine fleet of Astronomical Union (IAU), Dr. Winkler was Geosource and was responsible for the negotiation, sales, and an organizing committee member of IAU installation of marine navigation systems to the People’s Republic Commission 19 (Rotation of the Earth), past of China. Dr. Gernot Winkler president of IAU Commission 31 (Time) As General Manager of the Starfix Division of John E. Chance and a member of the group’s Commission 4 & Associates (later OmniStar and then Fugro), he developed and (Ephemerides). managed orbit-tracking software, established a communication Together with Dr. F. Reder, Dr. Winkler system, developed integrated user systems, and managed Fugro’s proved the feasibility of transporting precision world-wide Differential GPS Service. atomic clock time by aircraft in 1959 Dr. Ott had a distinguished career in GPS, received numerous while with the Signal Corps Engineering awards and citations for his accomplishments in the field, authored Laboratories, Fort Monmouth, New Jersey. He and presented professional papers at conferences all over the received the 1988 I. I. Rabi Award from the world, and was affiliated with numerous professional societies and IEEE for his “early development of worldwide organizations. He was active in the ION for many years, was a Dr. Lee Ott clock synchronization through use of portable founding member of the ION’s Satellite Division, and an early clocks; encouragement and support for the development of atomic organizer of the annual ION GPS (today’s GNSS+) meeting — frequency standards from their earliest days; and international serving as publicity chair and exhibits chair multiple times. leadership in the time and frequency community.” Dr. Ott earned his B.S., M.S. and Ph.D. in electrical An excerpt one of Dr. Winkler’s last memoirs included the engineering from Iowa State University. He is survived by his son following: “I had followed the Wegeners on the Greenland Ice, and Jeffrey and wife Kay, whom he met in high school, and to whom had my own little expedition to the South Pole. A great blessing he was happily married for 53 years.

Summer 2016 17 ION Newsletter SMS SMS SMS SMS SMS SMS SMS SMS SMS

ANGRY BIRDS ummingbirds make up in speed and aggres- Hsion what they lack in size. Although they use personal violence with each other as a last resort, anyone who watches the tiny beasts is familiar with the chittering, chirps, swoops, dives and chases that tell you all is not well. Composite of Anna’s Hummingbird courting dive and a male of the species, This summer, your reporter was in the backyard Images by Chris Clark, Yale University, observing two Anna hummingbirds in an aerial who discovered the unique tail sounds at the end of the male courtship for fight worthy of a dogfight on the Western Front. National Science Foundation in 2008. How do they do it, she wondered. Why don’t they crash into the ground? A team from the University of British Columbia found out the birds avoid such dramatic exits using a particular kind of visual cue. Anna’s Hummers, one of the fastest birds in the world, flew through an eighteen-foot tunnel with still and moving objects projected on the walls. They navigated by registering how fast the images in their field of vision change height. (The scientists got them to fly with a sugar syrup reward at the end of the tunnel. Hummingbirds drink a lot of it.) In a press release, the chief investigator said, “When objects grow in size, it can indicate how much time there is until they collide even with- out knowing the actual size of the object. Per- haps this strategy allows birds to more precisely avoid collisions over the very wide range of flight speeds they use.”

Painting of a First World War dogfight involving British and German biplanes in 1918. “Incident on the Western Front,” A Faroe Islands sheep outfitted with camera and communications from the UK Imperial War Museum. equipment takes pictures near Tjørnuvík, a small village on Stremoy Island. (Screen capture from the sheepview360 blog).

ION Newsletter 18 Summer 2016 SMS SMS SMS SMS SMS SMS SMS SMS SMS

DO THE LOCOMOTION arvard researchers have created a new form of Hlocomotion in robots using animal cells. A penny-sized robot made of translucent silicone and shaped like a tiny stingray is powered by heart muscle cells from rats. The navigable bot moves through a fluid obstacle course by fluttering its “fins” using energy from light hitting the cells. This animal/machine is nothing like the legendary “Prepare to be assimilated” Borg of Star Trek fame, we assure you. But it is a big step forward for scientists working with hybrid robots. Made by the Harvard Disease Biophysics Research Group, the robot contains 200,000 cells The light-guided bio hybrid robotic stingray in a serpentine pattern on the outside of its outer shell. The cells are harvested from rat hearts and then genetically engineered to contract when hit with pulses of blue light. By making the light flash faster or slower and aiming it at either NIST UT1 Internet side of the bot, scientists can steer the “stingray” through the course. In an interview with Science News, chief researcher and bioengineer Time Service Kit Parker used an example from his daughter’s childhood to explain he Time and Frequency Division of the National how it worked. When she was little, Parker would point his laser Institute of Standards and Technology (NIST) pointer at the sidewalk and she’d try to stomp on the dot. He could T operates an Internet time server guide her down a path as she followed the light. that transmits UT1 time in the Network Time Proto- As the father-and-daughter team learned, “She got to be col (NTP) format. independent and I got to make sure she didn’t step out into traffic.” The server is synchronized to UTC(NIST) by a direct connection to a local cesium standard. The offset SHEEPISH between UT1 and UTC is added to the reply to a he 48,000 people occupying 18 rocky islands between query for the time. The time difference between UT1 TIceland, Scotland, and Norway have a problem. They live and UTC is obtained from the International Earth in a beautiful place, but even Google Street View doesn’t know Rotation Service (IERS) Bulletin A, and the value used where they are. by the time server changes every day at 0 h UTC. The However, the Faroe Islands have resourceful citizens and time step at 0 h UTC is generally about one to two 80,000 sheep and they know how to make do. milliseconds, which is generally too small to be detected Durita Dahl Andreassen, with the assistance of a local farmer by most users. and an expert in animal tracking, built custom equipment and The accuracy of the time at the server is approximate- a 360-degree camera to get her country on the map. With the ly four milliseconds and is determined by the uncer- camera, a mobile phone, and some solar panels gently mounted tainty in the prediction of the difference UT1-UTC in on its back, cooperative sheep can wander at will around the the IERS Bulletin A. The accuracy of the time received islands and record pictures. by a user will usually be limited by the stability of the The pictures are sent with GPS coordinates to Durita, who network delay from the user’s system to the time server. uploads them to Google Street View. The overall accuracy of the time as received by a user In a press release, she said, “It is the strangest thing that I can- will generally be better than 10 milliseconds and will not show my friends in other countries where I am from. My often be significantly better than this value. home country is beautiful, green and kind of undiscovered to The name of the server is ut1-time.colorado.edu and the rest of the world — but I do not want it to stay that way,” its address is 128.138.140.50. The ut1 time service is To see the plan in action, visit . Please address any questions or comments to . ION

Summer 2016 19 ION Newsletter GNSS Program Updates News from Systems Around the World

hile the U.S. GPS program submission of the Selected Acquisition the Federal Register notice indicated, Wcontinues to struggle with delays Report (SAR) by the Office of Secretary attributing this to several factors, includ- and cost overruns in modernization of its of Defense, and then an Undersecretary ing the “lack of a regulatory requirement operational control system — along with of Defense for Acquisition, Technology for vessels to carry DGPS equipment threatened congressional funding cuts as a and Logistics (USD (AT&L)) led assess- within U.S. territorial waters, technologi- result, the world’s other GNSS programs ment of the program. Re-certification or cal advances in GPS that have increased have moved ahead with new launches and termination of the program will depend its accuracy, increased reliability of other program development. on the findings of this assessment. The GPS augmentation systems that do not Nunn-McCurdy process is expected to require a second receiver, limited avail- GPS conclude October of this year. ability of consumer-grade DGPS radio On June 30, Secretary of the Air Force Meanwhile, the GPS Directorate is beacon receivers, and the discontinuance Deborah Lee James declared a critical requesting public comments on proposed of GPS Selective Availability.” Nunn-McCurdy breach on the GPS changes to several interface specification Receiver Testing. Another Federal Next-Generation Operational Control (IS) and Interface Control documents Register notice, this one published on System (OCX). (ICDs) for GPS signals in space. GPS July 7, announced Department of Trans- After a December 2015 Program receiver designers will be particularly portation (DoT) plans to conduct addi- “Deep Dive,” Undersecretary of Defense interested in the changes as they affect tional testing of GPS/GNSS receivers this for Acquisition, Technology and Logistics how GPS signals should be processed in month as part of their Adjacent Band Frank Kendall placed the OCX program user equipment. Compatibility (ABC) Study. The notice under significant Department of Defense Affected documents are IS-GPS-200H, was issued by DoT Assistant Secretary (DoD) oversight with quarterly reviews. IS-GPS-705D, IS-GPS-800D, ICD- for Research and Technology Gregory The quarterly reviews also considered GPS-240A, and ICD-GPS-870B. The Winfree. off-ramp mitigations in the event OCX comment period will close on August The additional lab testing will be does not stay on track. GPS III Con- 19, 2016. The comments are in prepara- conducted at Zeta Associates in Fairfax, tingency Operations (COps) is already tion for the next meeting of the Interface Virginia, and MITRE Corporation in being implemented as a bridge to cover Control Working Group (ICWG) on Bedford, Massachusetts. It takes place in the OCX Block 1 delays. Additional September 21–22. Downloadable com- the context of a renewed push by Ligado mitigation options are being prepared ment forms are available on the . Federal Communications Commission capabilities. NDGPS Phase-Out. On July 5, the (FCC) approval to establish a terrestrial An Air Force headquarters press an- U.S. Coast Guard, the U.S. Army Corps wireless broadband network in the United nouncement said that factors that led of Engineers (USACE), and the Depart- States in radio frequency spectrum near to the critical Nunn-McCurdy breach ment of Transportation (DoT) announced the band occupied by GPS L1 signals and include inadequate systems engineering at a reduction in the number of reference those the other GNSS systems. program inception, Block 0 software with stations in the Nationwide Differential The goal of the ABC Study, overseen high defect rates, and Block 1 designs Global Positioning System (NDGPS). through the DoT’s Office of the Assistant requiring significant rework. Addition- A Federal Register notice said the Secretary for Research and Technology ally, the complexity of cybersecurity planned reduction will shut down and (OST-R), is to evaluate the adjacent requirements on OCX and effect of those decommission 37 DGPS sites, leaving radio frequency band power levels that requirements on development caused 46 operational sites available to users in can be tolerated by GPS/GNSS receiv- multiple delays. Corrective actions to coastal areas. Termination of the ND- ers. It is also designed to advance DoT’s resolve these problems took much longer GPS broadcasts is scheduled to occur on understanding of the extent to which than anticipated to implement. August 5, 2016. such power levels impact devices used for The process for a critical Nunn-Mc- The move to reduce the NDGPS transportation safety purposes, among Curdy breach requires the service secre- network stemmed from the stagnation other GPS/GNSS applications. tary to notify Congress, followed by the of transportation-related use of NDGPS, Ligado's own testing, however, makes

ION Newsletter 20 Summer 2016 GNSS PROGRAM UPDATES it clear that some GPS receivers would be Not all of the results from Ligado’s adversely affected by Ligado signals unless tests are publicly available, however, and those receivers are equipped with differ- GPS experts have repeatedly called the Calendar ent antennas or other changes are made, company’s test methodology into ques- including lowering the power of Ligado's tion. Specifically, the widely accepted of Upcoming signals. yardstick for measuring interference is a The current Ligado proposal is similar one-decibel decline in the signal-to-noise to ones made when the firm was still ratio or C/N0. ION Events called LightSquared but has a few ad- The Adjacent Band Compatibil- ditional elements. Of the two 10-mega- ity Assessment, now underway under SEPTEMBER 2016 hertz bands closest to the GPS frequen- the sponsorship of the Department of 12-16: ION GNSS+ 2016, Oregon cies Ligado would formally abandon the Transportation, is using a change of one Convention Center, Portland, Oregon Contact: The ION 1545–1555 MHz downlink band, leaving decibel to develop a set of masks, that Tel: +1 703-366-2723 it the 1526–1536 MHz band for down- is, limits by frequency on the amount of Fax: +1 703-366-2724 links. It would also reduce the effective interference that can be safely tolerated by Web: www.ion.org isotropically radiated power (EIRP) limit GPS devices. LightSquared consistently NOVEMBER 2016 for this band from 42 dBW to 32 dBW. took issue with the signal-to-noise metric 8-10: International Navigation Conference Ligado has also requested that it be al- saying that using the actual change in (INC), Glasgow, University of Strathclyde, lowed to share the 1675.0–1680.0 MHz the position accuracy determined by a UK band now used by the National Oceanic receiver is more appropriate. Contact: The Royal Institute of Navigation and Atmospheric Administration. It GPS Backup. The Department of Tel: +44 (0)20-7591-3134 already has the frequencies from 1670.0 Homeland Security (DHS) is moving Email: [email protected] to 1675.0 MHz. Sharing would give it a forward to establish a backup for the posi- Web: www. total of 10-megahertz to make up for the tion, navigation, and timing (PNT) infor- internationalnavigationconference.org.uk frequencies it is abandoning. mation provided by GPS. The agency has JANUARY 2017 To help make its case, Ligado launched assumed the lead in a yearlong effort to January 30-February 2: ION International tests in June 2015 of more than two specifically define the requirements for an Technical Meeting (ITM) & ION Precise dozen different GPS receivers. It has now alternative source of timing information Time and Trime Interval Meeting (PTTI) 2017, Hyatt Regency Monterey, Monterey, filed the full results in FCC IB docket 11- to and released a solicitation for research California 109 along with an analysis that describes to help protect critical infrastructure from Contact: ION the test plan and provides charts of the timing disruption or spoofing. Tel: +1 703-366-2723 results. The backup envisioned by the National Fax: +1 703-366-2724 Conducted by telecommunications Executive Committee for Space-Based Web: www.ion.org experts Roberson and Associates, the tests PNT (ExCom) will be a complementary May 2017 look at 27 different GPS receivers serving PNT system (CPNT) that runs continu- 1-4: ION Pacific PNT, Marriott Waikiki the general navigation, high-precision, ously, side-by-side with GPS, said Harold Beach, Honolulu, Hawaii non-certified aviation and cellular "Stormy" Martin, the director of the Contact: ION markets. This represents a fraction of the National Coordination Office (NCO) for Tel: +1 703-366-2723 hundreds of different models of GNSS Space-Based PNT. The NCO provides Fax: +1 703-366-2724 receivers on the market today. support to the Space-Based PNT Execu- Web: www.ion.org Of the 12 general navigation receiv- tive Committee (ExCom), a multi-agency 09-12: ENC-GNSS 2017, Lausanne, ers, Ligado reported that only one was group led by the departments of defense Switzerland affected by an LTE (cellular) signal in and transportation that guides federal Contact: ENC 2017 Conference Office one of the bands Ligado wants to use PNT policy. Email: [email protected] Web: http://enc2017.eu — and that only happened when "the The CPNT will not be "like a flash- device was in motion, and at LTE power light and candles that you have in a JUNE 2017 levels that will occur with extremely low drawer that are only used when the lights 5-8: ION JNC 2017, Dayton Convention probability." go out," Martin told Inside GNSS. It Center, Dayton, Ohio Contact Of the 11 high-precision GPS receivers will be a backup "that would be used, : The ION Tel: +1 703-366-2723 tested, however, only four were unaffect- basically, all the time so that, in case GPS Fax: +1 703-366-2724 ed. Three receivers showed "no impact" if had a problem, the transition would be Web: www.ion.org a filtered antenna was added. seamless. That's really because a lot of

Summer 2016 21 ION Newsletter GNSS UPDATES the modern uses of positioning, naviga- A new dispenser for the Ariane 5, capa- ing station in Tahiti, Verhoef said. More- tion, and timing information tend to be ble of carrying four satellites into middle over, an invitation to tender has gone out machine to machine — it's at that kind Earth orbit, has passed an extended test to industry for the third batch of eight of speed — and you want everything to campaign and approved for launch, satellites with an option for six more. be well rehearsed, well understood, and removing a final hurdle for accelerating Finally, the Federal Communications seamless." development of the Galileo constellation. Commission (FCC) appears to be mov- The ExCom decided at its June meet- In development since 2012, the new ing on a request from the Europe Union ing to have DHS spearhead development launcher design evolved from the Ariane to waive licensing requirements that are of timing requirements for U.S. critical 5 ES (Evolution Storable) that is used thwarting full use of Galileo signals in the infrastructure. That effort will follow a to carry European Space Agency (ESA) United States. process outlined in Presidential Policy automatic transfer vehicle (ATV) supply The original request for a waiver was Directive 21 (PPD-21) — Critical Infra- spacecraft into low Earth orbit. made in October of 2013, according to structure Security and Resilience. PPD- The dispenser underwent comprehen- a report attached to National Defense 21 identified 16 critical infrastructure sive testing at Airbus Defense and Space Authorization Act for Fiscal Year 2017 sectors — communications and water, for near Bordeaux, France, and the Indus- by the powerful House Armed Services example — and the federal agencies that trieanlagen-Betriebsgessellschaft MBH Committee. The report added that the would be the primary contact points for committee believed that "approval of working with the largely private-sector Progress with the Galileo such an allied positioning, navigation, owners and operators in charge of that program have given and timing system could meet impor- infrastructure. tant national security goals, including The Department of Transportation will managers confidence that the goals outlined in the National Space lead the development of timing require- they will be able to declare Policy." ments for the transportation sector. The the availability of "initial" Already in use in commercial receiv- timing-requirements effort will begin ers, Galileo signals could, if approved this fall and should take about a year to services in October. for official use, make police and other complete, Martin said. government receivers more reliable and Getting specific about how to backup (IABG) testing center in Ottobrunn, accurate. With the waiver Galileo could the other information — positioning and Germany — using both Galileo engineer- also be incorporated into requirements navigation — provided by GPS would ing models and an actual flight satellite. for services such as E911 where more sig- come later, he said, as would a timeline for Tests included fit, shock, and separation. nals make it easier to narrow the location when to have a CPNT system in place. The dispenser is now at the European of distressed cell phone callers in densely The ExCom came out in December spaceport in French Guiana, ready for populated areas. in favor of a two-step process in which installation on Galileo’s first Ariane 5 While a number of steps had to be enhanced Loran (eLoran) would be de- launcher scheduled to take off this fall.. completed before the FCC could post the veloped as a near-term alternative to GPS The modified Ariane launcher is waiver for public comment — and then for timing data while the ExCom deter- designed to dispense one satellite into make a decision — the committee points mined what capabilities would be needed each of four orbital planes. The Galileo out that that preliminary work is done. for a comprehensive GPS backup. While program plans to launch four more satel- In fact it's been done since January 2015 the new requirements process appears to lites in each of the next two years. when the National Telecommunications delay development of eLoran it does not Progress with the program has given and Information Administration (NTIA) necessarily preclude it. its managers confidence that they will sent a letter to the FCC saying that it had be able to announce the availability of "concluded that the Galileo system and Galileo “initial” Galileo services in October, fol- the European Commission request 'meets The European GNSS program added two lowing a security clearance expected early the criteria NTIA previously established more spacecraft to its constellation with that month. Those will include the Open to grant the waiver.''' the launch of Galileo satellites 13 and Service civil signal, a search and rescue 14 in May. This was Galileo’s last flight service, and the encrypted Public Regu- BeiDou using a Russian Soyuz rocket before the lated Service (PRS). China launched another BeiDou satellite first launch using a customized Ariane 5 Meanwhile, efforts continue to com- on June 12, the 23rd satellite in the Bei- that will carry four rather than two satel- plete upgrades to the widely scattered Dou Navigation Satellite System (BDS). lites each time — which is set to occur ground segment, including the security The satellite, G7, is a new-generation on November 17. monitoring station and another monitor- BeiDou-2 spacecraft and the seventh

ION Newsletter 22 Summer 2016 GNSS UPDATES geostationary Earth orbit satellite (GEO) BDS service in the regional area of The GLONASS constellation cur- in the BeiDou constellation. operations has achieved availability of rently has 27 operational spacecraft, 24 of Also in June, the Chinese government 99.996 percent of the time, according to which are transmitting “healthy” signals, published a white paper outlining the ac- Ran, which is higher than the 95 percent two as on-orbit spares, and a GLONASS- tion plan for BDS and a press conference availability when the system officially K satellite undergoing flight tests. Seven featuring the director of the BDS man- began offering services. Continuity of GLONASS-M satellites are stored at agement office provided new details on service “has surpassed the fundamental ISS-Reshetnev’s facilities as ground spares. the progress for China’s GNSS program. criterion of 99.5 percent and reached Another spacecraft has been out of service The white paper, the first of its kind for 99.986 percent,” he added. Real-time since 2014 but remains in the constel- BeiDou, was released by the State Coun- stand-alone accuracy reportedly is better lation almanac and monitored by the cil Information Office (SCIO). It basi- than five meters, below the 10-meter satellite prime contractor. cally codifies and recapitulates the policies specification. Meanwhile, according to the TASS and development timeline for BDS that state news agency, the state corporation have been announced previously. How- GLONASS "Roscosmos" has ordered the delivery of ever, comments by Ran Chengqi, director A GLONASS-M satellite, (GC#753), three Soyuz-2.1b rockets for launching of China's Satellite Navigation System launched in May was set healthy on June GLONASS-M satellites from the Plesetsk Management Office and one of the most 27, replacing an eight-year-old satel- in 2017. Launch of a Proton rocket with prominent spokespersons for the BeiDou lite (GC#723) in orbital plane 2, slot three GLONASS satellites from the system, shed additional on the achieve- 11. GC#723 has been placed in reserve Baikonur cosmodrome in Kazakhstan is ments and direction of the program. status. expected by the end of this year. ION

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