@Amiga4000 I didn’t test it with the Mapillary app because I don’t use it, but it should work, as the app can replace the internal gnss receiver.
@tryl I use BlueGps or Bluetooth GPS BlueGPS can record the nmea file Bluetooph GPS can’t record nmea directly (you need another app) but it shows some other informations like satellite reception quality, …
I don’t know “Mobile GPS” but the Navspark’s are good,… if you have a good antenna. And it’s even better with the antenna on the car’s roof, as It gives you a better reception and less multipath problems. I didn’t test, but it should be better in urban canyon area.
But you won’t have submeter accuracy, it’s only a standard gnss receiver with Gps, Glonass, and Sbas for dgps.
If you want something really better, you need to look at Real Time Kinematic. I’m testing RTK with another Navspark (NS-HP-5), but it’s another, more complex, world.
As far as I understand, RTK requires 2 GNSS receivers: A “rover” and a “base”. The base is stationary and the precision of the setup depends on how well you know the exact position of the base (as well as how well you have placed the antenna). The rover is the moving part.
Can that be made practical for Mapillary (or OSM) use? Centimeter precision is pointless of I don’t even know the location of the base with that precision.
You’re right, base + rover, and radio/network link between the base and the rover.
Yes, if you don’t know the base coordinates, you will get only centimeter relative precision, which is better than nothing.
There are many workaround to have a good base position:
start with a known location, and put your base on it
start with an existing base station
record the base location for a few hours, then postprocess it to get a more accurate location.