Could you please advise us the range of satellite elevation? We expected it is in the range from 0 to pi/2 radian but in one of our simulation experiment by Skydel with code as below,
el_az = sim.call(GetElevationAzimuthForSV(“GPS”, svId))
el_az_func = el_az.elevationAzimuth()
el = el_az_func[‘Elevation’]
We obtained negative el, around - 0.0117 rad.
In our scenarios, the pseudo offset is computed as
pseu_off = 2hmath.sin(el)
The negative offset then triggered the error when the following function was called
sim.call(SetMultipathForSV(“L1CA”, svId, 0, pseu_off, 0, 0, 1, id))
It might depend on the altitude of the vehicle. If the vehicle is flying at a significant altitude then satellites could legitimately be located below the local horizon of the vehicle.
Thank you very much for your kind response. In my experiment, the vehicle is at Fixed location with altitude 1km. Not sure if there is a chance the satellites below the horizon of the vehicle.
At at altitude of 1,000m and an earth radius of 6,363,564m, I calculated the local horizon to be a distance of approximately 112,810m away. That gave an angle below the local horizon of 0.00886 radians. Your angle of 0.0117 radians is a little larger so that doesn’t fully explain your result, although it does show that negative elevation angles are possible.
Thank you very much for the helpful explanation.