Reference Station, NTRIP Server, & RTK2Go Data Loss & GPS Changes?

GPS/GNSS Enclosed Products
1

We just checked a monument and found we are about a couple feet off horizontally, and 6" different in elevation. We are using SW Maps, and RTK Express. We use NTRIP Server connected to the Sparkfun Reference station on site.

We confirmed with a secondary rover we have setup. At least they both align. But they’re both misaligned from the past couple months that we’ve been using it.

We checked the reference station antenna, and it is firmly in place.

We noticed the bytes we were receiving from the NTRIP server are about 500 when we were used to seeing about 1,500. This is reflected in the following graph from RtK2go.

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We typically calibrate every time we go out, which would be December 5 and December 10. We didn’t seem to notice any miscalibration issues on December 10.

Any ideas on what could cause a misalignment?

2

The volume of data could relate to the mix or periodicity of the RTCM3 messages. Say GPS vs GPS,GLO,GAL,BDS

How was the position of the Base set into the device, SURVEY-IN vs specific and consistent static position?

3

I went through these steps to get the base station location:

https://learn.sparkfun.com/tutorials/how-to-build-a-diy-gnss-reference-station#gather-raw-gnss-data

4

“Return to the TMODE3 message and enter the ECEF coordinates from the report. Assuming this receiver is attached to a fixed antenna, we recommend saving these settings to BBR/Flash so that every time this receiver powers on it will immediately enter TIME mode and start outputting RTCM data.”

Does this mean every time I turn off and turn on the reference station, and I did not save these settings to BBR/Flash, my system will be uncalibrated?

Perhaps this is the reason?

5

Using legacy UBX-CFG-TMODE3 / UBX-CFG-MSG methods is not going to retain settings unless you explictly use UBX-CFG-CFG to push them into Non-Volatile storage.
Using Generation 9 Methods you can impart the storage level(s) via the UBX-CFG-VALSET

6

I had reset the Reference Station, and had to reinput the data, and issue resolved.

Is there a tutorial that explains how to save this information so on restart it automatically has the data?

7

Hi @jeffersonkim ,

Clive is describing how you would configure a ZED-F9P manually, so that it saves the surveyed-in base position. With the RTK Firmware running on the RTK Reference Station, the position is actually saved to SD card (and also ESP32 non-volatile memory) and restored when the firmware restarts. Please see: Creating a Permanent Base - SparkFun RTK Product Manual

I hope this helps,
Paul

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