Post-processed base point shifts but rover points do not

[oajioka]

I have an RTK project where the base station data was downloaded and post-processed through DPOS with the option "Base-Rover + Base CORS Processing" and in the points table it shows the CORS position for the base, but the rover points only have RTK(fixed) or RTPK(fixed) columns not RTK(BCP) or PPK(BCP). Also, in the points list only the base station shows the "open circle => closed circle" icon next to the point number.

Furthermore, when I go to the DPOS screen, open the options and choose "Base-Rover Processing Only", and re-DPOS it says "0 points base processed (REL)"

Could this be due to some setting that I missed? Can someone help me understand why I can't get my rover points to shift?

 

[Nate The Surveyor]

Does it have a localize in it?
If it does, you MUST press the Localize Button, and THEN it will update the Localize.
Nate

 

[oajioka]

No localization, since this was a base station position we had occupied in the past we had a coordinate for it and selected "Known Base". The DPOS position is in agreement with our previous coordinate.

I know in this situation (with a known base station) we don't necessarily need to DPOS. The issue is that our rover shots are not in agreement with some of our old work by ~0.9'. The rover shots are self-consistent however (distances between rover shots check). So I am scratching my head trying to figure out what happened, and whether it has anything to do with the post-processing.

I uploaded the project to support (24236904_Gps1).

 

[oajioka]

Still trying to understand this issue.

I post-processed again with the option "Base-Rover + Base & Rover CORS Processing" which as far as I understand is essentially what RTPK is doing (CORS processing rover points). This didn't seem to change anything.

My base station point is 125000.1, with a "Post-Processed with CORS Data" coordinate of:
N: 2,137,965.6468
E: 5,990,082.4234
U: 13.4865

When I look at my rover points I see several coordinates: Current, Base Station, Survey Origin, Base Station Origin, Post-Processed Origin, Base Station Origin Post-Processed.
Base Station, Base Station Origin, and Base Station Origin Post-Processed all have the same coordinate.

Comparing the "Base Station Origin Post-Processed" coordinate to 125000.1 above:
N: 2,137,964.8782
E: 5,990,082.8550
U: 13.6517

this is a difference of
N: 0.7686
E: -0.4316
U: -0.1652

Or a horizontal distance of ~0.88' in a NW/SE direction, which matches the shift we're seeing at the rover points.

Does this mean the RTK vectors are originating from a different coordinate than the post-processed base station?

 

[David M. Simolo]

I don't know all of the intricacies of this but the one thing that caught my eye was using a "know base". If I am putting my base on a previously determined point I use "select" "from list" and enter the old point number that way. Whether this has any bearing on your situation is unknown to me.

 

[JoeD]

Let us know what you find out from support.
This has happened to me a number of times. What seems to fix it is to click on the point that is your base. You will probably see it has CORS checked instead of Auto (or Known). Go ahead and change it back to Auto (Or known). It will ask if you want to shift associated points. Say yes. Then do the opposite, click the point and this time Change it back to CORS. It will again ask if you want to shift associated points. Now when you check your points it should say ABS next to them instead of Auto (or Known). This doesn't always work for me, not sure why but most of the time it does.