Quite often get pop up warning terrain e.g. "Climb above 1500'" but already flying much higher than that. Why is this?
Thanks

When you get this alert I suggest that you look at the virtual radar display.  You may be descending at that instant and SD is warning you of a possible problem if you continue on your current descent trajectory.

George E A Reid

Ipad Mini 5,  IOS 14.4,  SD 3.15.0.288
PC(Win 10, Version 19041.804)  SD 3.15.0.0

Plausible. I'll check. But, if this the case, it seems a bit over sensitive as I'm sure any descent in such cruise would be temp due to turbulence or my clumsy flying.. Perhaps the SD guys will confirm. Thanks

Other people have reported when playing back tracks from SD that have been taken using a built in tablet GPS, that their altitude drops to zero at seemingly random times during the flight. This can be seen on the elevation display at the bottom. Do a review of the flight to see if this is/was the case. I can only think that the built in GPS on tablets is losing the altitude somehow, maybe through a drop out of number of visible satellites. I don't seem to get it, but I have a canopy aeroplane. I also these days generally use the WAAS/EGNOS enabled GPS on my PilotAware as my GPS source.
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SkyDemon will warn you about an obstacle if by the time you get there, with your current trajectory (including vertical) you would be below a safe height above it, simple as that.

As others have said, it would be worth checking the virtual radar or your GPS altitude when this happens so you can get a feel for why it's happening. You may also wish to reduce the time-to-threat required to trigger the warning, which is set at three minutes by default.