First off im new to all of this so please excuse me if im asking a dumb question.
I have an RTK GPS I use for my archaeological work. Is it possible import a GGA string from the RTK data into the APM? GPS_PROTOCOL_NMEAAP_GPS_NMEA is available in the APM code - but it is not an option in the APM_Config.h file. Does this mean its the default setting - or simply not a supported feature?
My RTK is way too heavy for a drone of course . . . Im just playing around with the boards and thought it would be fun to collect some data to compare to the ublox.
Thanks for any help!
Replies
Exercise:
1. What is the major effect on ortophoto georeferencing precision,
IMU angle estimation error of 1 percent or RTK postprocessing?
2. RTK only works BECAUSE the GPS is stationary all the time when the measurement is being taken.
If it moves one meter up and back, 2 meters left and right, and changes angle, the reception conditions change and there is little information to be taken.
3. Find RTK 5Hz update rate below 5KUSD. Not that 5Hz is absolutely necessary all the time, but to compare to our current solution.
I think it is very common to assume for 'terrain level people' that their 'most expensive toy' will do any good up there. No chances. They were DESIGNED for constant altitude, up to the last centimeter. Includes car navigation equipment (constant alt to the last meter, no vertical accelerations for more than 0.1s or so). Then you can squeeze a meter or two under certain conditions.
Even military GPS are UNABLE to hit a window unless secondary targetting, laser in particular, is provided.
Of course military propaganda is another story but 2m CEP remains valid for them.
We don't actively support NMEA, but as you noted it is something we have played with in the past and there is a library there for it. I suspect it doesn't work right and I certainly wouldn't fly with it, but might work for bench testing--try selecting . None of the developers have NMEA GPS modules anymore, so it's not something we're actively developing, but if there's demand for it from the OSD crowd in the future, we might get a member of the community to take that on.
I can confirm that #define GPS_PROTOCOL GPS_PROTOCOL_NMEA compiles, but as to what data comes out, I'll leave to you to experiment.