Retrieving base location for RTK survey

Reach RS2 / RS2+ RTK / PPK configuration
1

Hi,
I conducted an RTK survey with two RS2’s using LoRA. The problem I encountered is that the coordinates of the base station, which I set at the start of the survey to be used by the rover, were not recorded properly (screenshot only contained the latitude).
Questions: can the base location at the start of the survey be retrieved after the survey?
I outline my workflow below.

Thanks,

thor

workflow
• set-up base station
• take ‘single average’ of the base (for < 1 min)
• take screenshot of base location used by rover for survey
• start rover and start new survey
• conduct survey
• switch of rover and base
post processing
• download base and survey .csv
• conduct base correction through NRCAN
• calculate difference between base location used for survey and the final base location
• correct survey data

2

If you used RV3, the base coordinates are in the CSV file for each registered averaged position.

4

Thanks! Unfortunately it is RV2. Good to know RV3 does store it.

5

Hi Thor,

Did you record the base correction log on the rover during the survey? If yes, you can convert it to RINEX in our RTKLIB version and get the base’s position in ECEF XYZ format from the header.

1 Like
6

Hi Tatiana,
Not knowingly, how can I check for the base correction log? For survey project export I get the list of options (GeoJSON, etc). I always manually take a screenshot of the base location used by the rover (but this failed).
I know I started my survey within a couple of minutes of setting the base location and I was wondering if I can retrieve the location recordings from the base during that specific period and at least be able to approximate the location retroactively. Is that possible?
Cheers,
thor

7

Hi Thor,

By default, Reach devices should log the base correction data. If you haven’t turned off this option manually, you should be able to download the logs corresponding to the day and time period of your survey in the Logging screen.

Please note that logs are recorded in the UTC time.

1 Like
8

This is great news Tatiana. In the 'logging ’ menu ‘Raw data’, ‘Position’ and ‘Base correction’ are all switched on and I downloaded the files from the survey. In which of the files can I find the base corrections used for the survey and how do I access it (.RTCM3, .BX and .LLH files)? If there is Emlid documentation covering this I’d love a link (couldn’t find it). Cheers, thor

1 Like
9

Hi Thor,

You can convert the RTCM3 file to RINEX using our version of RTKLIB. We have a guide explaining how to do that.

After that, you can open the RINEX file in the text editor and check the base position in the header.

1 Like
10

Thanks Tatiana for the excellent help.

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12

Here’s a question, while using our RTN, can you download the VRS base file ? I would think you could, depending on EMILD’s computing of the VRS position. I may be wrong though

14

Bryan,

Thanks for your patience!

You can record the base correction log from VRS as well. This log will be possible to download in the Logging section afterward.

1 Like
16

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