After working successfully for 18 months, I now get many drops in my internal GPS. Even sitting outside in the garden with a perfect view of the sky, GPS Status and Google Maps give perfect results, but Skydemon is 'Waiting for location' more than half of the time. This problem started about 6 weeks ago. 

Using SD 3.0.7.19226 on Android 4.4.4

I am using GPS Status already. If I have trouble it shows 0/8 satellites. I think this means 0 satellites 'read' out of 8 visible. Right now it is fairly steady 8/8. The green flag in the ALT window shows, yesterday is was green/yellow/red.

While I am writing this, SD will show 'Waiting for Location' for a few seconds, and then resume. It is now off permanently, the first 10 minutes were steady on, now steady off. Regained contact...

I wonder if this has anything to do with the troubles in Ukraine?

I think that if GPS status is frequently flipping from 0/8 to 8/8 and back again it looks as though there is a problem with the GPS receiver in your device.

I think that SkyDemon uses the DOP (Dilution of Precision) figures which are shown by the GPS Status app to determine if the location is accurate enough to use (not sure what the actual values are that it requires - maybe Tim can enlighten us). It is likely that SkyDemon requires better accuracy than Google Maps etc before accepting the GPS output as usable for navigation.

Simon