Inside GNSS Media & Research

NOV-DEC 2017

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24 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 to make the test more comprehensive and lead to a compat- ibility assessment. ey decided those were out of scope. So, I think it's dangerous to list that as a test, with the implication that it leads to a compatibility assessment when that was not the specific intent." "I agree with you sir that it was not the specific intent," Green said. "They did in fact develop a test methodology which, I happen to think is great and they did in fact do it (the testing). And as a result of that there was, in fact, data which our engineers interpreted. at's what engineers do with data." It was that interpretation, she indicated, that sup- ported the assertion that GPS operators and Ligado could coexist Signal expert Logan Scott followed a data-focused approach, using results from earlier tests to give a fuller pic- ture of the NASCTN test results. In one example the data indicated high precision and RTK receivers with ordinary antennas would lose lock at about 8 kilometers from the inter- ference source. Another example showed receivers perform- ing better in the face of interference — suggesting, he said, based on his experience, false signal acquisition. It's All in the Details In the end, the lack of technical specifics from Ligado played a role in the Advisory Board's decision to dra a letter opposing allowing the firm to proceed under its modified concept of operations. Beyond the problem with being able to fully eval- uate the plan there was concern about whether the proposed power levels would stay where they are and about interference with uncertified aviation receivers — including those to be used in the fast-growing drone industry. e members broadly agreed, however, that should Ligado come back with a fleshed-out plan, one that addressed the interference concerns, then the Advisory Board should give them another opportunity. "We're a public board. We're serving the taxpayer. If it's an issue still on the table and we think it's important to GPS — and they come in and say 'Hey we got you this time. We're really going to tell you' — I think we've got to let them talk," said Parkinson. e letter is to go to the National Executive Committee or ExCom, the focal point for interagency decisions involving PNT. Comprising top leaders from across government the ExCom is co-chaired by the deputy secretaries of Defense and Transportation — Patrick Shanahan and Jeffrey Rosen, respectively. It is expected to meet sometime this January. ough some Advisory Board members recused them- selves all the remaining members voted to back the ExCom letter as outlined. "e PNT Advisory Board strongly believes," the dra said at the end of the meeting, "that approval of the new license modification application is not in the public interest and the proposed use should not be permitted. All members of the PNT Advisory Board who have not otherwise recused themselves are unanimous in this view." WASHINGTON VIEW • ITAR free • Small size, low weight, power and cost • Insensitive to magnetic fi elds • Low gyro bias instability (0.3°/h) • Low gyro noise (0.15°/√h) • Low accelerometer bias instability (0.05 mg) • Excellent performance under vibration and shock • Fully calibrated and customer confi gur able to the specifi c application • 3 inclinometers for accurate leveling • Weight 55 grams, volume <2cu.in, power 1.5 W STIM300 is fi eld proven in Military Land navigators, Missile systems, Target acquisition systems, Airborne surveillance, DIRCM, Remote Weapon Systems, Launch vehicles and Satellites. STIM300 is a tactical grade Inertial Measurement Unit, IMU, for demanding guidance and navigation applications. sales@sensonor.com • www.sensonor.com When size, performance and robustness matter 1:1 scale TACTICAL GRADE IMU

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