Reach RS base unit - achieving a FIX solution

popenc · April 4, 2018, 4:15pm

Hi everyone, just a heads up / warning, I’m quite new when it comes to GPS, RTK, etc., so bare with me : )

This isn’t really an issue, but more so a question of setting things up correctly. Before I get into all that, here are some details about my setup:

Base unit and rover unit are both Reach RS devices.
ReachView app is version 2.10.0 for both units.
A space about a half football field in size that’s free of buildings and other obstructions.
Access to a nearby NTRIP (< 10km) station.

The problem I’m having, or really the expectation I have, is that the base unit would be able to obtain a FIX solution after setting its “Correction Input” to use the NTRIP station nearby, which would then enable me to set the base unit’s position (under “Base Mode” settings) to “Average Fix” instead of “Average Single.”

The goal is to be able to set accurate (sub meter) points in the field (e.g., for the base’s location, and for manually setting test waypoints) by having the base unit do an “Average Fix.”

The following are the settings for the base unit:

RTK positioning mode: Static
RTK GPS AR mode: Fix-and-hold
Correction Input: NTRIP
Base Mode corrections output: LoRa (sending to rover)

The following are the settings for the rover unit:

RTK positioning mode: Kinematic
RTK GPS AR mode: Fix-and-hold
Correction Input: LoRa

I can provide any additional settings if they’re needed.

The behavior I’m seeing with this setup, is that after the base does an “Average Single” to determine its position, the rover gets a FIX solution after a few minutes, but the base unit is always in a Single solution state despite the correction input with the NTRIP station.

Is there something I’m setting incorrectly for integrating the NTRIP corrections into this setup?
Should the rover unit also be getting corrections from NTRIP and not from the base via LoRa?

Below is an image showing the base unit’s correction input with the NTRIP tower.

Any help is appreciated, and sorry if this isn’t in the write topic, or a duplicate, etc.

Nick

egor.fedorov · April 14, 2018, 7:49pm

This is more of question of getting a FIX on your base first.

Please post a screenshot of incoming messages in the correction input screen. It’s the little tick to the right of the green “Connected to …” text.
Make sure you have Glonass AR turned off on the base
What’s the actual status you have?

popenc · April 17, 2018, 1:43pm

Thanks for the info, Egor!

It turned out I didn’t have the Mount Point for the NTRIP corrections set to the right one. Our nearest tower’s mount points are mostly CMR and CMR+, but I found one that does RTCM3, which I’ve gathered is the format the Reach RS units understand.

Here’s a screenshot to show the connection message, in case anyone else has ran into this problem:

The difference in this screenshot compared to the other one (since both say they’re connected), is that the one directly above had a dropdown which is showing incoming data.

Now our base unit gets a correction from the NTRIP station, and gets to a Fixed state rather quickly. Below is a screenshot of the Status section of the Reach RS base unit:

One thing I was wondering, is about the Reach’s base unit’s base when getting Input Corrections, if that makes sense. The base unit is getting corrections from the NTRIP tower in town a few miles away, but it shows that it has a base at some distance 1.62m away from it.

Is the base position on the base unit’s “Status” page showing where the base unit thinks it is, while the position is showing the corrected position from the NTRIP tower?

thanks!

Nick

egor.fedorov · April 17, 2018, 2:49pm

Yep, it appears when there is actual data incoming.

You are probably using a caster with VRS, a virtual reference station. It’s a neat trick that imitates a base station right next to your rover.

davehofer1993 · April 17, 2018, 9:19pm

system · July 26, 2018, 9:19pm

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