This rant applies to most appliances that display GPS "status" whether cell phones, car GPS, and so on ... and the MP RC and GO displays.
This rant is prompted by a comment by another poster trying to figure out why he had "No GPS" state despite 15 sats and "5 bars of signal (max)".
I'm not addressing his issue, at least not directly (there seems to be various comments about healthy appearing GPS but the MP is in ATTI mode...)
GPS does not have a cell phone like "signal" level on a receiver. It (internally) has signal level for each satellite. The displayed "5 bars" is a mashup to give the user some indication of what the GPS is providing. It is misleading in some cases as a "poor" 5 bar can display when there is more than adequate coverage - and v-v.
Generally if you have as few as 4 GPS satellites in a geometrically dispersed pattern (in 3 directions, low elevation about you and one reasonably high above you), then you'll get a very accurate fix. Today's constellation of GPS guarantees that (in open areas) you will likely have 6 - 10 satellites. In most of the continental US and southern Canada you'll also receive 2 or 3 SBAS sats. Same in Europe and Japan. These not only give GPS ranging functions but corrections for all the other sats and health status of them as well. And then GLONASS.
Our devices dumb all this down into location and a "status" bar. Indeed on the MP controller we're lucky to have the satellite count at all!
I really wish they would show the scatter plot of where the sats are relative to the receivers along with a colour grade for the signal from each satellite. That would help diagnose issue related to the system reverting to ATTI when it should stay locked in GPS. Or maybe not - the issue at present may be some s/w or f/w glitch that DJI may in its good time resolve... having that plot of individual GPS (and GLONASS) sats would go a long way to sorting that out.
Rant over.
This rant is prompted by a comment by another poster trying to figure out why he had "No GPS" state despite 15 sats and "5 bars of signal (max)".
I'm not addressing his issue, at least not directly (there seems to be various comments about healthy appearing GPS but the MP is in ATTI mode...)
GPS does not have a cell phone like "signal" level on a receiver. It (internally) has signal level for each satellite. The displayed "5 bars" is a mashup to give the user some indication of what the GPS is providing. It is misleading in some cases as a "poor" 5 bar can display when there is more than adequate coverage - and v-v.
Generally if you have as few as 4 GPS satellites in a geometrically dispersed pattern (in 3 directions, low elevation about you and one reasonably high above you), then you'll get a very accurate fix. Today's constellation of GPS guarantees that (in open areas) you will likely have 6 - 10 satellites. In most of the continental US and southern Canada you'll also receive 2 or 3 SBAS sats. Same in Europe and Japan. These not only give GPS ranging functions but corrections for all the other sats and health status of them as well. And then GLONASS.
Our devices dumb all this down into location and a "status" bar. Indeed on the MP controller we're lucky to have the satellite count at all!
I really wish they would show the scatter plot of where the sats are relative to the receivers along with a colour grade for the signal from each satellite. That would help diagnose issue related to the system reverting to ATTI when it should stay locked in GPS. Or maybe not - the issue at present may be some s/w or f/w glitch that DJI may in its good time resolve... having that plot of individual GPS (and GLONASS) sats would go a long way to sorting that out.
Rant over.