eTrex x0x GLONASS Anomalies
Posted: Sat Aug 03, 2019 8:51 pm
My eTrex 30x (3.00) Satellite page is doing some things I can not reconcile.
First, the eTrex 30x tracks all visible GLONASS satellites correctly, and provides an accurate enough position, but it identified the GLONASS satellites with the wrong NMEA ID numbers. It uses NMEA ID that are correct for GLONASS, but they are not the correct numbers for the visible satellites. In fact, I have been doing some testing, and compared the eTrex 30x to many other Garmin GPSr that also receive GLONASS satellite signals, as well as multiple tablets, phones, and satellite tracking web pages. They all agree with each other except for the eTrex 30x, which always misidentifies the GLONASS satellite ID numbers.
Second, the eTrex 30x, and only the eTrex 30x indicate it is receiving Differential Correction Data (SBAS) for the GLONASS satellites. I have been in contact with various PR people at the EGNOS HQ in Europe and the FAA WAAS HQ in the US, and the answers I am getting is that nobody calculates or otherwise makes available SBAS data for GLONASS satellites. EGNOS is scheduled to begin doing so in 2025 when their newest generation of satellites are all put into orbit, but not until then. How in the world does the eTrex 30x think it is receiving augmented data for GLONASS satellites if nobody is transmitting it? Space Aliens? No other GPSr suggests this information is available, only the eTrex 30x
Finally, I am in the USA, so I have two or three WAAS satellites available to me for SBAS data, and they are all due south of me, about 45° above the horizon (over the equator), a little West or East, but primarily south of my location. Yet, for some reason, the eTrex 30x indicates that WAAS satellite 44 is due NORTH of my location and nearly at the horizon, which is just completely wrong.
Does anyone else observe similar behavior with any eTrex x0x or x2x?
The following images demonstrate these issues clearly:
First, the eTrex 30x tracks all visible GLONASS satellites correctly, and provides an accurate enough position, but it identified the GLONASS satellites with the wrong NMEA ID numbers. It uses NMEA ID that are correct for GLONASS, but they are not the correct numbers for the visible satellites. In fact, I have been doing some testing, and compared the eTrex 30x to many other Garmin GPSr that also receive GLONASS satellite signals, as well as multiple tablets, phones, and satellite tracking web pages. They all agree with each other except for the eTrex 30x, which always misidentifies the GLONASS satellite ID numbers.
Second, the eTrex 30x, and only the eTrex 30x indicate it is receiving Differential Correction Data (SBAS) for the GLONASS satellites. I have been in contact with various PR people at the EGNOS HQ in Europe and the FAA WAAS HQ in the US, and the answers I am getting is that nobody calculates or otherwise makes available SBAS data for GLONASS satellites. EGNOS is scheduled to begin doing so in 2025 when their newest generation of satellites are all put into orbit, but not until then. How in the world does the eTrex 30x think it is receiving augmented data for GLONASS satellites if nobody is transmitting it? Space Aliens? No other GPSr suggests this information is available, only the eTrex 30x
Finally, I am in the USA, so I have two or three WAAS satellites available to me for SBAS data, and they are all due south of me, about 45° above the horizon (over the equator), a little West or East, but primarily south of my location. Yet, for some reason, the eTrex 30x indicates that WAAS satellite 44 is due NORTH of my location and nearly at the horizon, which is just completely wrong.
Does anyone else observe similar behavior with any eTrex x0x or x2x?
The following images demonstrate these issues clearly: