Tech Chat | An Easy Way of Setting Projected Coordinate Systems – RTCM 1021-1027 Messages

In some countries, their local CORS will also transmit the projected coordinate systems information via RTCM1021 -1027 messages. By this way, surveyors and GISers do not need to set the datum parameters any more. Let's see how do RTCM1021 -1027 work and how to use them?

In the last blog we introduced the RTCM protocol, normally we use RTCM32 messages to transmit RTK correction data in most RTK scenarios.

But in some countries, their local CORS will also transmit the projected coordinate systems information via RTCM1021 -1027 messages. By this way, surveyors and GISers do not need to set the datum parameters any more. So how do RTCM1021 -1027 work and how to use them?

What are RTCM 1021-1027 messages?

The RTCM1021-1027 contains some local Datum transformation information, details as below.

As you can see, it includes projection parameters and 7 parameters etc.

Therefore, with RTCM1021-RTCM1027, users can get correct local coordinates without setting all the coordinate parameter details when doing RTK. It saves time configuring datum parameters and will also protect the privacy of your local coordinate system parameters.

How to use the RTCM 1021-1027 messages?

Surveyors may have seen this setting in RTK software settings, but how should we use it?

1. First of all, you need to make sure whether the CORS account you are connecting to transmits RTCM1021-1027 information, which depends on the CORS provider
2. Then you should confirm if your RTK receiver and field software support this feature. Not every GNSS device and software support these messages.

As an expert GNSS device provider, SingularXYZ provides 2 field surveying software that supports RTCM1021-1027- the basic version SingularSurv and the professional version SingularPad.

In SingularSurv, users can tick the RTCM1021-1027 options when setting the CORS work mode. Then the software will receive the Datum information from the CORS. In SingularPad, users can directly select the coordinate systems parameters type as RTCM1021-1027 parameters.

More about SingularSurv
https://www.singularxyz.com/SingularSurv.html
More about SingularPad
https://www.singularxyz.com/SingularSurv.html
More about Y1 GNSS receiver
https://www.singularxyz.com/Y1_Land_Surveying_Solution.html