GPS Status


GPS Info ScreenGPS Status (GPS Info window) allows user to monitor current GPS or GNSS performance. It contains number of useful information and some information might be specific only to externally connected GNSS (global navigation satellite system) system able to provide RTK corrected coordinates.

GPS Info Screen

 

The RTK corrected coordinates accuracy depends from the class of the external device. The RTK information is being taken directly from the NMEA stream which is being fed to the Android device (MapIt).

To connect external GNSS device to MapIt please follow the following steps:
1. Make sure the device is paired in Bluetooth settings. 2. Enable Mock Location in Android Developer Settings (In Android 6 please set MapIt as Mock Location application) 3. In MapIt settings go to External GPS and switch ON the External GPS switch. 4. When getting back to map the location source will be automatically switched to External GPS (you may need to restart app on some devices).

GPS Information like HDOP, VDOP, PDOP, VRMS, HRMS, Correction Station ID, Correction Age etc. can be included with POINT layers and this can be enabled in ‘Survey Settings’.

 

*During the beta testing few GNSS devices with centimetre accuracy were tested, however if you have tested the solution and it works for you as well I would appreciate if you provide the details of the device used in the comments below this post. 

 

Your external GNSS device must stream at least following sentences to get MapIt working properly with RTK corrected coordinates and to be able to display VRMS and HRMS values:

GGA Message (location, fix type, correction age, correction station id):
Sample: $GPGGA,144349.80,5738.2912621,N,01157.1781140,E,4,13,1.1,23.307,M,36.10,M,02,0883*60
GST Message (vrms, hrms - calculated from lat, lon error):
Sample: $GPGST,144350.00,1.78,0.02,0.01,6.7589,0.02,0.01,0.04*6F
GSV Message (Satellites info):
Sample: $GPGSV,4,1,13,02,02,213,,03,-3,000,,11,00,121,,14,13,172,05*67
GSA Message (HDOP, VDOP, PDOP):
Sample: $GPGSA,A,3,04,05,,09,12,,,24,,,,,2.5,1.3,2.1*39
RMC Message (Speed):
Sample: $GPRMC,123519,A,4807.038,N,01131.000,E,022.4,084.4,230394,003.1,W*6A

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