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DoD GPS Testing Prevents UAV Mission

Tuesday, December 6, 2016 17:03

Imagine you have a client needing you to conduct a mapping survey of a parcel. Or you yourself are an architecture-engineering-construction (AEC) firm and one of your FAA-licensed unmanned aerial vehicle (UAV) pilots just arrived on site to conduct a surveying mission. You conduct your standard pre-flight check and low-level equipment airworthiness test flight, launch your mapping app, start your mission and thanks to the U.S. Department of Defense (DoD) conducting GPS testing at that time, the app fails the Home Point check criteria. 

That was our experience recently. The app requires "seeing" signals from at least 14 satellites before launch to assure the precise location of the launch (home) point for an automated mapping mission. On this day, only 13 were seen. Typically, our UAVs can see as many as 18 satellites during operation. To learn about what may be happening, we reported a GPS service outage to the United States Coast Guard Navigation Center (NAVCEN). Within an hour, they replied that the DoD was conducting GPS testing during the time of our planned mission. 

To mitigate adverse effects on flights, we have added steps to our flight planning protocol and pre-flight checklist to check for planned GPS disruptions and forecasted space weather events. We check with the United States Coast Guard Navigation Center, cross-reference with in-the-sky.org, and check with National Oceanic and Atmospheric Administration (NOAA). Contingency protocols have been implemented to account for unplanned satellite disruptions. 

This is an excellent example of the advantage of outsourcing aerial imaging services to a professional UAV service provider with FAA-licensed pilots experienced to check for such details in planning and executing an aerial mission.