Interface Position

Geoidal separation in meters

In meters above MSL (but see issue #359)

HAE altitude in meters - can be used instead of MSL altitude

1-100 (0 means not provided)

GPS fix quality (from NMEA GxGGA statement or similar)

GPS fix type 2D/3D (from NMEA GxGSA statement)

GPS accuracy (a hardware specific constant) in mm multiplied with DOP to calculate positional accuracy Default: "'bout three meters-ish" :)

Ground speed in m/s and True North TRACK in 1/100 degrees

The new preferred location encoding, divide by 1e-7 to get degrees in floating point

Horizontal, Vertical and Position Dilution of Precision, in 1/100 units

• PDOP is sufficient for most cases
• for higher precision scenarios, HDOP and VDOP can be used instead, in which case PDOP becomes redundant (PDOP=sqrt(HDOP^2 + VDOP^2))

Estimated/expected time (in seconds) until next update:

• if we update at fixed intervals of X seconds, use X
• if we update at dynamic intervals (based on relative movement etc), but "AT LEAST every Y seconds", use Y

A sequence number, incremented with each Position message to help detect lost updates if needed

Pos. timestamp milliseconds adjustment (rarely available or required)

Positional timestamp (actual timestamp of GPS solution) in integer epoch seconds

GPS "Satellites in View" number

Sensor ID - in case multiple positioning sensors are being used

This is usually not sent over the mesh (to save space), but it is sent from the phone so that the local device can set its RTC If it is sent over the mesh (because there are devices on the mesh without GPS), it will only be sent by devices which has a hardware GPS clock. seconds since 1970