Here in Australia, we have a free CORS network (AUSCORS), which is broadcasting in GDA2020, the latest datum, but the majority of projects I work on still reference GDA94. My question is, is it possible to convert an NTRIP stream, in real time, from GDA2020 back to GDA94 ?
You can use the Custom coordinate system setup with the transformation from GDA2020 to GDA94. This can be done via 7 Helmert parameters. Besides them, you also need projection parameters. You can check them in the required coordinate system in ReachView 3 by tapping the info button.
And what is really nice coincidence is that our Custom coordinate system setup guide describes the exact transformation you require. You can read it here in our docs.
Oh, I thought I read that the project projection had to be the same as the projection for the corrections received from the ntrip base. Is that not correct? How does the RS2 know what projection the corrections are in?
The rover’s coordinates will be in the same datum as the base has, that’s how it works by default. But its coordinates can be transformed into another datum by applying transformation parameters.
Reach RS2 acting as a rover doesn’t need to know the base’s datum. It just applies GDA2020 to GDA94 transformation to incoming data. Indeed, if the NTRIP base has another datum, the outcome coordinates will be incorrect. But as long as you know your provider streams in GDA2020, everything is fine.
Hi Brocxen. I followed the doco to convert auscors to 94 in z55. The Emlid doco has an error in the scale factor when entering the Scale factor for Projection it should be 0.9996 and not 0.9966. Give that a try
Please record several points in this custom CRS (GDA2020-to-GDA94 / MGA zone 50) and corresponding CRS without transformation (GDA2020 / MGA zone 50). Then, send us two resulting CSV files to support@emlid.com. I’ll check with the team what may cause such an enormous difference in the coordinates.