re: #74 ericblair

There’s no big mystery why there are a lot of UFO sightings in Nevada. Although civilian ATC not picking up a military aircraft wouldn’t be unusual, if the aircraft had its transponder off and was in restricted areas or high enough that It’s None Of Your Damn Business.

There were a few funny stories about some research balloons a number of years ago. Scientists would release balloons to the upper atmosphere with GPS units attached to them, and the GPS would stop working and they didn’t know why. They did figure out that civilian GPS chips were programmed to stop responding if they recorded over a certain speed or altitude, since at that point GPS receivers were considered munitions and subject to export and usage restrictions. I think they’ve relaxed this in the last few years to allow more of this type of use.

I was going to say, 20 years ago when we were doing high-altitude research balloons as test flights of our satellite program at our university (testing the data link radios and control/telemetry software), we had no problems with recording altitudes upwards of 70,000 feet.