UAVForecast.com uses a proprietary model to simulate the expected number of GPS satellites you will be able to lock, given the following factors:
The number of GPS satellites visible in the sky (filtered by the elevation mask).The time of day: ionospheric interference with GPS is worse at night.Your latitude and longitude: ionospheric interference is worse close to the equator.The current or forecast Kp index.
Note that the estimate is just that - an estimate - and the actual number you see will vary according to local conditions, random fluctuations in the ionosphere, and so on.
I've seen accessories where they actually sell Antennas that you put on top of your Vehicle so you can have warm Fingers by Flying your drone in Cold Temps from the Comfort of your Car!! lol For instance here's one... http://amzn.to/2mSAsUT