Variable satellite signal while in one spot ???

[kirbinster]

I was flying my P2V+ at a local park yesterday and recorded the telemetry info from my iPhone screen. In playing it back I notices that while I was up in the clear at about 225 feet that as I did a slow 360 yaw to look around the number of birds varied between 6 and 9 while I was in one position just rotating. Most of the time it was 7 or 8 but I was surprised that it would go all the way from 6 to 9 while in one spot, is this normal?

You can see this starting at about 2:05 in this video: http://youtu.be/xLo-xoR1xOQ

 

[Great Pumpkin]

Yes, it may vary, depending on the configuration of the satellites, depending on what things stand between your UAV and the satellites, such as a building or big trees, and whether solar flares were strong enough to interfere with Earth electronics. Some of the satellites will be low on the horizon, some rising and some setting. True, ordinarily the variation should not range from 6 to 9. I was out with two hand held GPS units and saw that by in large they received the same number of satellites as my P2V while the variation was usually no more than 7 to 8. If you were having so much variation last weekend, it could have been due to two extremely strong solar storms.

 

[noiseboy72]

GPS satellites continually move, so you do get long term variations - over 5 minutes or so, as the appear over the horizon, but your shorter changes are just due to the fact that the aerial is not truly omnidirectional, so as you pan around, the signal strength changes a little.

Nothing to worry about and quite normal.