Additional RTCM Data Stream Logging to increase accuracy in post processing

Overview

The RTCM data stream is stored along with all other raw data files. Since RTCM data is the only data that is not generated at the rover, the logged data suffers from connection interrupts and the resulting data gaps can not be closed during post processing. This is mostly the case if a local RTCM station is used and the distance to the rover exceeds the range of the Wifi connection e.g. during flight operations.
The postion accuracy can be increased for the data analysis of post processed data sets if the RTCM data stream is logged in parallel without any connection interrupts. Therefore the SNIP NTRIP Caster can be used. The program should run on a laptop which is connected to the RTCM station’s Wifi and should be positioned within its range.
The following steps show you how to setup SNIP for your RTCM station.

Setup SNIP to log RTCM data

1. Step: Download SNIP from www.use-snip.com/download and install it on your laptop

2. Step: Start SNIP
Go to “Relay Streams” to add your RTCM stream

 

3. Step: Add new NTRIP Caster stream
There might already be a few streams in the list ( remove with >right click >Remove ). Hit “Add New Stream” to add your required RTCM stream to the list

 

4. Step: Connect to stream with your credentials
Type in the Hostname/IP and the port of the NTRIP Caster you want to access. Use the username and password which you have received from the provider. Connect to the correct mountpoint. If the mountpoint is unknown or more than one option is possible, you can hit the button “Get Mount Points” to receive a list of all active ones for this station. Hit OK to add the new stream to the list of your Relay stream.

 

5. Step: Stream added
The newly added stream appears in the list. If RTCM data is being transmitted the green color appears.
Disconnect the stream with >right click >Disconnect.

 

6. Step: Log Stream Data
Log data with >right click >Log raw data. If this option is checked once it stays active until it is unchecked again. The default directory for data files is …/bin/data.

 

7. Step: Monitor real time data
RTCM messages can be watched in real time. This option can be enabled
with >right click >Show in RTCM3 viewer

Important

  • SNIP trys to connect to all streams in the list every startup unless they were manually disconnected before closing the application.
  • Run time is restricted to 1h. After that SNIP has to be restarted to run again for 1h. Check www.use-snip.com for more information