I have two RS2+ receivers. I have set one as a base station and logged it’s position for 24 hrs and then processed those results using the CSRS-PPP website. I waited a week or so before uploading to get the most accurate coordinates. I am in the UK so requested the coordinates in ITRF2020 coordinate system.
I have read that I have to convert from ITRF2020 to ETRS89 but after converting the coordinates given from the CSRS-PPP report there was no change. So, inputted these coordinates manually as my base station coordinates and connected the base station RS2+ to send the corrections via Emlids Ntrip caster to my rover over wifi.
I am able to pick up the corrections on my rover using a data only sim card and recieve a fix in very little time.
The problem I have is that I am on a building site which has been set out from known datums, ie various datum nails that I assume were coordinated via a survey grade GNSS reciever by the intial survey company. I am setting out drainage and roadways using a total station, with the view of using the more durable and weather proof RS2+ for kerb setting out and doing road level topos. I inputted the E,N,Z of the known datum nail as a point in the emlid flow app, but, when I set up my rover over these points with known E,N,Z the rover is saying I am around 700mm in the wrong place.
I have tried different coordinate transformation sites to go from the CSRS-PPP reported ITRF2020 to ETRS89 to OSGB1936 but cannot get it spot on. Starting to think that the intial datum nails were put in with an error and the whole job and site control points were taken from them. But, given me being very new to GNSS it is more likely that I am not converting the coordinates correctly somerwhere along the line and that is whats causing the 700mm error.
These are the websites I have been using to convert the CSRS coordiantes for my base station.
For ITRF2020 to ETRS89 Transform coordinates - GPS online converter (no change in coordinates)
From ETRS89 to OSGB1936 OS-Net | Ordnance Survey
If there are any users out there who have setup a base station using CSRS and set out on jobs using the OSGB1936 coordinate system please could you help me with your workflow.