Inside GNSS Media & Research

NOV-DEC 2017

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22 Inside GNSS N O V E M B E R / D E C E M B E R 2 0 1 7 www.insidegnss.com told Parkinson, noting again there was not an extensive operational assessment. D oT 's K a ren Va n D y k e br ie f ly reviewed for the board the ABC Assess- ment results so far, having presented them at an earlier meeting. She noted that some high-precision receivers, which are a focus of concern for interference, could be impacted by a tower transmitting kilo- meters away. Air Force Weighs In e Air Force also spoke about the work they had done for the ABC Assessment including their participation in the plan- ning and the testing they had done. Though the results are classified, said Capt. Robyn Anderson, who is in GPS Spectrum Management at the GPS Directorate, the DoD test results support the conclusions briefed by the DoT and "we fully support and back those recom- mendations and encourage decisions to be made upon those data driven recom- mendations." e goal is not to prevent any type of innovation, said Anderson, but we can- not support innovation that will degrade GPS operations. The Air Force also gave attendees a paper addressing the value of using a 1 decibel (dB) decrease in C/N0 as the appropriate interference protection cri- terion – that is a measurement intended to indicate when you are nearing a level of harmful interference as opposed to the level that causes harmful interference. "So the Air Force does obviously support the 1 dB interference protection criteria," Anderson said noting that by the time a military receiver experiences harmful interference it's too late and the mission could be put at risk. "W hen you're ta l k i ng about t he framework of national security that to us is not acceptable at all," Anderson said. "So our focus will continue to be on protecting the radio frequency environ- ment instead of handpicking receivers and transferring the interference mitiga- tion responsibility to the receiver manu- facturers." NASCTN Controversy Green answered a question about her characterization of the tests done by the National Advanced Spectrum and Com- munications Test Network (NASCTN) as showing that GPS operations could coex- ist with a Ligado network — an assertion made during her talk that has been said also in other forums. "A l t h o u g h y o u r e f e r e n c e d t h e NASCTN tests there," said Betz, "I think it's very important to understand what NASCTN itself said the objectives of that test were. And, as you know there were two objectives — one was to develop a test methodology and the other was to illustrate that test methodology. There was never an attempt to actually develop the definitive results that would lead to a compatibility assessment. And in fact, as you know, there were many comments that suggested things that could be done WASHINGTON VIEW Delivering Aviation Approved GPS Solutions…Worldwide. www.aspennexnav.com Copyright 2017 Aspen Avionics Inc. "Aspen Avionics," "NexNav", "MAX," "Micro-i," and the Aspen Avionics aircraft logo are trademarks of Aspen Avionics Inc. All rights reserved. U.S. Patent No. 8,085,168, and additional patents pending. Approved NexNav ™ GPS solutions for the aerospace industry have a well-proven track record in civil and military, manned and unmanned applications. • GPS-SBAS circuit card assemblies and GPSSUs • Small size, lightweight and low power consumption • Approved for ADS-B OUT position source • Approved for enroute, terminal and approach GPS navigation • Products meet all expected GPS requirements for UAS BVLOS operations • Made in U.S.A. • Go to www.aspennexnav.com for more information Compact Size • Small size, lightweight and low power consumption • Approved for ADS-B OUT position source • Approved for enroute, terminal and approach GPS navigation • Products meet all expected GPS requirements for UAS BVLOS operations

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