Description
- ROVER: Forward RTCM 1005, 1006, 1007 to data collector with NMEA (configurable)
EDIT: Updated to be more specific. See discussion in #431
Not actually sure if forwarding the RTCM 1005, etc., to the data collector will achieve the ultimate aim. I'd be willing to help test with my data collector if there was some way to stream a test data set to it and see how it responds.
Previously titled: Provide Base Location in Rover data stream and log
The "log" part of the original #405 I captured in #447.
Subject of the issue
The Rover knows the position of the Base. Enhance the data stream from the rover, and the rover log file, to contain the location of the base.
This would be useful for validating the coordinates of the base when processing the rover data. This would also connect the base coordinates to the rover data without needing paper, pencil, phone photos, .csv files on SD cards, etc. The base coordinates would be in the rover data, reducing potential misunderstandings of where the base was when the rover data was collected.
Initial capability could be to simply provide the ECEF of the base antenna phase center with a $GNTXT message in the Rover log and/or data stream. By the time the rover starts getting RTCM from the base, the base should have locked down it's location.
Potential future enhancements could include providing the coordinates in LLh, providing the id of the base mark (point#), base HI (ground-to-ARP), base antenna type, ARP->APC offset, etc., if this information can be obtained.
It appears that most surveyor-grade commercial GNSS receivers provide the base location to the data collector. That information can be recorded in the data collector log files. These receivers also appear to get the HI (ground to arp, height of instrument), the antenna type, and the antenna offsets from the base.
For example, the ".RAW" and ".RW5" files written by data collectors from multiple major survey data collector manufacturers contain a "BP" -- Base Point -- record that contains information about the base. The data collector software will write these records when connected to the base and also when connected to a rover.
Here's an example BP record written by SurvPC
BP,PNBP001,LA39.245469902207,LN-76.465103374896,EL111.7164,AG2.1000,PA0.0925,ATAPC,SRBASE,--
PN: point number BP001
LA, LN in ddmmss.sss
EL - ellipsoid height
AG - ARP above ground (HR)
PA - phase center to ARP distance
Your workbench
f/w 3.1
Expected behavior
RTCM 1005 contains the ECEF coordinates of the Base antenna phase center.
The rover knows where the base is, or at least where it thinks it is (survey-in or fixed setting).
Output the base coordinates in the NMEA data stream and/or the rover log.
Apparently there is a NMEA message for this, though I haven't been able to find it. The release notes for SurvPC v5.08 state
"The NMEA GPS driver now supports getting the base position."
https://web.carlsonsw.com/files/updates/updates05.php/?ss_email=&product=SurvCE&ss_email=&version=5.0&serial=&ss_email=