DMR TA APRS not working for Southern or Western hemisphere
Posted: Sun Nov 13, 2022 10:43 pm
Does anyone know how I can get in contact with the Brandmeister developers, because sending "In Call GPS" via DMR to BM only works correctly for positive values of Latitude and Longitude.
Negative values e.g. Southern or Western hemispheres, result in invalid locations being reported by https://aprs.fi
The BM Self Care settings only seem to support Motorola or Hytera GPS data, but I can't find any information online about whether their data format is different from the ETSI standard data format.
According to the ETSI standard the GPS information is send in the last TA 'phase" of 7 bytes
The first 4 bytes are the Longitude and the last 3 bytes are Latitude.
Actually first byte also contains accuracy information and reserved binary bits, so that most of the Longitude data is sent in bytes 1,2 and 3
Sending 0xFFFFFF in the Latitude bytes should result in a position of -0.000001 deg i.e south, but results in a large positive value on APRS.fi, which is out of range.
So either the hemisphere data is sent in a different byte entirely, or one of these 2 systems is not working correctly
Edit.
I tried posting to the aprs.fi Google group, but my question was rejected by the moderators, as not being applicable to the aprs.fi website
Negative values e.g. Southern or Western hemispheres, result in invalid locations being reported by https://aprs.fi
The BM Self Care settings only seem to support Motorola or Hytera GPS data, but I can't find any information online about whether their data format is different from the ETSI standard data format.
According to the ETSI standard the GPS information is send in the last TA 'phase" of 7 bytes
The first 4 bytes are the Longitude and the last 3 bytes are Latitude.
Actually first byte also contains accuracy information and reserved binary bits, so that most of the Longitude data is sent in bytes 1,2 and 3
Sending 0xFFFFFF in the Latitude bytes should result in a position of -0.000001 deg i.e south, but results in a large positive value on APRS.fi, which is out of range.
So either the hemisphere data is sent in a different byte entirely, or one of these 2 systems is not working correctly
Edit.
I tried posting to the aprs.fi Google group, but my question was rejected by the moderators, as not being applicable to the aprs.fi website