Before the FEDERAL COMMUNICATIONS COMMISSION Washington, D.C. 20554

In the Matter of ) ) Expanding the Economic and Innovative ) Docket No. 12-268 Opportunities of Spectrum Through Incentive ) Auctions

COMMENTS OF THE UNIVERSITIES SPACE RESEARCH ASSOCIATION

Universities Space Research Association (hereinafter, "USRA"), hereby submits its

comments in response to the Commission's October 2, 2012 Notice of Proposed Rulemaking in the above-captioned docket (“NPRM”). In these Comments, USRA discusses certain proposals in the NPRM regarding observations in the Service (“RAS”) at 608-614 MHz

(i.e., Channel 37). USRA supports retaining the current allocation for RAS at Channel 37, and urges the Commission to maintain protections for RAS observation in that band.

I. Introduction.

USRA has an interest in this proceeding due to its relationship with the Arecibo

Observatory in Arecibo, Puerto Rico. The (AO) is part of the National

Astronomy and Ionosphere Center (NAIC), which is operated by SRI International under a cooperative agreement with the National Science Foundation, and in alliance with Ana G.

Méndez-Universidad Metropolitana, and the USRA. The 305 meter William E. Gordon at the AO is the largest single-dish radio telescope on our planet. The AO has a long history of being the site where very significant accomplishments in astronomy have occurred, including:

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- the first discovery of planets outside of our own solar system; and

- discovery of the first pulsar in a binary system, leading to important confirmation of Einstein’s theory of gravitational waves and a Nobel Prize for two radio astronomers who performed their research at Arecibo.

The radio telescope at the AO is an important tool for identifying new pulsars, for the

large-area mapping of neutral atomic hydrogen and continuum emission, for the compiling of

huge red-shift surveys of galaxies, for the detection of Hydroxyl mega-masers and other

molecules in ultra-luminous infra-red galaxies, and for much more. The study of a large number

of molecular species is now possible, the high end of the frequency range having been ”opened

up” by the Gregorian telescope upgrade of the mid-1990s. Additionally, appropriate

instrumentation has allowed the AO telescope’s participation in wide-band Very Long Baseline

Interferometry (VLBI), adding enormously to the sensitivity of this endeavor for the imaging of

the smallest scale structure in both line and continuum radio emitters. The AO telescope is a

regular contributor to the National Radio Astronomy Observatory’s High Sensitivity Array, the

European VLBI Network and to global VLBI Arrays.

Yet, as the Commission knows, this important and expensive scientific instrument is

extremely vulnerable to interference from unwanted emissions by other users of the spectrum. It

was for this very reason that the Puerto Rico Coordination Zone rules were enacted. See, e.g.,

Radio Astronomy Coordination Zone in Puerto Rico, Report and Order, 12 FCC Rcd 16522

(1997) (“PRCZ Order”).

II. USRA Supports Retaining the Current Allocation for RAS at Channel 37, and Maintaining Protections for RAS Observations.

The NPRM seeks comments as to whether the current allocation for RAS at Channel 37

should be retained, or whether an RAS allocation should be moved to a different frequency in the

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TV band. USRA supports retaining the RAS allocation at the current frequency of 608-614

MHz (Channel 37).

The spacing of most RAS bands with frequencies below 5 GHz was arranged to enable the detailed spectrum of continuum radio sources to be characterized adequately, which is often a matter of determining what fraction of their signal is due to synchrotron emission as opposed to thermal emission from hot gas. This is particularly necessary for Galactic sources located in the crowded plane of our Milky Way Galaxy, where thermal emission from their surroundings and along the same line of sight contributes to the signal. A noteworthy Arecibo example was the discovery of the first millisecond pulsar. This has a typical pulsar-type spectrum, after account is taken of its Galactic position and surroundings, but required equipment sensitive to a 1 millisecond pulse repetition rate to be deployed before it could be identified as a pulsar: the 33 millisecond Crab pulsar was, at the time, the fastest pulsar known, so this revolutionary advance was only achieved as a result of the confidence the observers had in their characterization of its radio spectrum. That has since spawned an industry, which has identified more than 100 millisecond pulsars. These collectively provide a stable timing system that tests our best terrestrial clocks, as well as an ongoing cutting-edge program that seeks to directly detect gravitational wave radiation.

The 608-614 MHz band is the only RAS band between 406.1-410 MHz and the 1400-

1427 MHz 21cm band. Its precise frequency for spectral characterization is unimportant: anywhere between ~550 MHz and ~850 MHz would serve. Hence any small, tens-of-MHz change is entirely acceptable for RAS purposes. While similar observations could be performed elsewhere in the 550-850 MHz frequency range, consideration must be made of costs to observatories associated with a change in the RAS allocation, if the change in frequency were

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more than a few 10’s of MHz. In addition, changing the RAS allocation from Channel 37 could

create confusion and a negative impact on RAS observation at 608-614 MHz in other countries.1

The NPRM raises the possibility of adjusting the Channel 37 allocation on a regional

basis, to optimize local frequency consolidations. Since the VLBA has a Channel 37 capability,

this of itself implies the utilization of a common band at every one of its sites: these sites span

the contiguous states, as well as St. Croix and Hawaii. Thus the RAS cannot support any change

that does not maintain uniformity across the nation in any substitute for Channel 37. Arecibo is

used in conjunction with the VLBA from time to time, so USRA would greatly prefer that the

RAS allocations adopted elsewhere in the country are maintained for Puerto Rico too. The

VLBA with/out Arecibo generates maps from the emission observed: the continuum maps are

often made to characterize the spectra of point sources, as well as the detailed structure and

spectral components of high velocity jets. When directed at Galactic targets, such as

remnants, star formation regions, and individual situations of interest such as potential pulsars,

magnetars, and gamma ray sources, the angular resolution of the VLBA helps to eliminate both

the effects of RFI and contributions from the astronomical surroundings. Thus the VLBA

promotes our ability to make millisecond-pulsar type discoveries.

Adding Arecibo to the VLBA, or any other VLBI array of telescopes, when these are

used to observe at frequencies below 10 GHz, provides a demonstrated increase in sensitivity of

at least a factor of four. The resulting “VLBI Telescope” is far and away the most sensitive point

source telescope on the planet. Moreover, the Observatory is currently commissioning a 12 m

telescope to continuously track a phase reference source to increase the sensitivity gain by a

further factor of √2, as this obviates the need for frequent movements between the source of

1 In response to the question in paragraph 204 of the NPRM, USRA understands that the Dominion Radio Astrophysical Observatory in Penticton, British Columbia, currently observes at 608-614 MHz.

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interest and the reference. This telescope also increases the possible range of target sources that can be profitably observed using Arecibo in VLBI configurations. These upgrades were undertaken as a result of a meeting convened by the Observatory in 2007 to explore future

science cases for Arecibo: the most unheralded of these cases extolled the new capacity provided

by the sensitivity enhancements of VLBI that enable radio emission to be observed for the first

time from a very wide range of ordinary stars. Among other objectives, this capacity will help to

tie the radio and optical reference systems together more accurately, with consequences as

diverse as improvements to space navigation for NASA missions, and greater precision of

measurements of the movement of the Earth’s pole and differential shifts of its tectonic plates.

While Arecibo does not currently have a 608 MHz receiver, one can be quickly repurposed for

the band when a project requires it.

The NPRM raises the possibility of a much larger frequency adjustment being under

consideration. There is no merit for RAS in making a jump to a substantially lower frequency, so

far as the original case for having a RAS band circa 608 MHz is concerned, though a jump

towards 800 MHz would be acceptable, both for the characterization of radio continuum sources,

and for refining at every observed epoch the dispersion measure of millisecond pulsars. Time

varying electron densities along the line of sight to millisecond pulsars generate temporal

changes to their dispersion measure, which adds noise into the accuracy of their timing

observations. That in turn impedes their ability to detect gravitational wave radiation.

Regardless of whether the RAS allocation remains on Channel 37 or moves to another frequency, RAS facilities will need protection from interference from White Space or TV Band

Devices (“TVBDs”). The Commission has previously recognized the need to protect RAS observations at Channel 37 in connection with TVBDs, as Section 15.707(a) of the

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Commission’s rules prohibits operation of such devices on Channel 37. In addition, pursuant to

Section 15.712(h), operation of such devices on any channel is prohibited within 2.4 kilometers of certain radio astronomy observatories, including the AO, and there are limitations on TVBD operation on the first available channel above and the first channel below TV Channel 37, as set forth in Section 15.707(a). Furthermore, out-of-band emissions into Channel 37 are particularly limited, pursuant to Section 15.709(c)(4).

The above cited protections of RAS observations at Channel 37 are justified, and USRA remains concerned about the real possibility of harmful interference from TVBDs if such devices were allowed to operate on Channel 37. Nevertheless, USRA recognizes the importance of sharing spectrum resources among services, where it is practical to do so, and thus USRA is open to consideration of temporal sharing between such devices and RAS facilities, subject to certain restrictions. Such sharing would require TVBDs to be able to sense their location and compare with the location of certain RAS facilities, as well as the ability to dynamically review the schedules for RAS observations on Channel 37 at those facilities. Of course, such dynamic temporal sharing would also have to provide protection to Wireless Medical Telemetry Service devices, which have been a good spectral neighbor for the RAS. Even if the Commission were to adopt provisions for dynamic sharing of Channel 37 with TVBDs, however, it would still be necessary to maintain the remainder of the protections of Channel 37 in the current Part 15 rules for TVBDs discussed above.

In addition, protection from interference by licensed services to observations by the AO at 614-608 MHz should be considered. For example, given that the goal of the rule changes explored in the NPRM is to increase the use of spectrum, USRA urges the Commission to remind users of the requirements of Sections 1.924(d), 73.1030(a)(2) and other sections of the

{00480584-1 }6 rules, which require notification to the AO spectrum manager by applicants for new, permanent fixed, individually licensed stations in the islands of Puerto Rico, Desecheo, Mona, Vieques, or

Culebra.2 In the PRCZ Order, the Commission found that such procedures served the public interest, and such procedures still serve the public interest.

III. Conclusion.

The Commission should retain the current allocation for RAS at Channel 37, and it should maintain protections for RAS observation in that band.

Respectfully submitted,

UNIVERSITIES SPACE RESEARCH ASSOCIATION

______Dr. Fernando Camilo Director of Astronomy, Arecibo Observatory

Arecibo Observatory HC3 Box 53995 Arecibo, Puerto Rico 00612

January 25, 2012

2 Sections 1.924(d), 73.1030(a)(2) and other sections of the Commission’s rules enacted or revised in the PRCZ Order now include outdated information. First, they reference interference guidelines to be provided by Cornell University, which is no longer the operator of the AO. Second, they contain an outdated postal address for the AO. USRA will seek to update these ministerial matters in an upcoming filing in ET Docket 12-338.

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