PPK Solutions

[Jim Campi]

Gentlemen,

A quick question on obtaining Post Processed Kinematic solutions. I've noticed that the option to save a point and process the rover's GNSS raw data is only available when there are zero fixed epochs. Over the last week or two I have had many cases where the LS might collect a few fixed epochs or even a single event and this precludes me from using the PPK feature.

1. Is this the way the system is designed?

2. Is it improper to obtain a PPK solution if there are a small number of fixed epochs or if it's not possible to obtain our configured number of fixed epochs?

3. Is there a way to obtain a PPK solution when there are a small number of fixed epochs?

 

[Shawn Billings]

Gentlemen,

A quick question on obtaining Post Processed Kinematic solutions. I've noticed that the option to save a point and process the rover's GNSS raw data is only available when there are zero fixed epochs. Over the last week or two I have had many cases where the LS might collect a few fixed epochs or even a single event and this precludes me from using the PPK feature.

1. Is this the way the system is designed?

2. Is it improper to obtain a PPK solution if there are a small number of fixed epochs or if it's not possible to obtain our configured number of fixed epochs?

3. Is there a way to obtain a PPK solution when there are a small number of fixed epochs?

1. No. If the collect process does not complete all of the settings (verification/confidence, consistency, validation, epoch count, time) and the APP epoch count exceeds user setting (i.e. 5 minutes) then you should be given the opportunity to store the raw data.

2. It is always a good idea to obtain a PPK solution (in my opinion) even if you have a good RTK solution so that you can compare the results. If you have a questionable RTK solution (few epochs) then it is even a better idea to obtain a PPK solution.

3. It should work as No. 1 above. For my control and boundary points I set What To Record to always record raw GNSS. I want to post process those points always so I force the system to always store raw data for those points, then I'm not worried about whether APP works or not. And, even if I get a successful RTK shot, I still like to post process for the added redundancy, so there are no times with control and boundary that I don't want raw data.

 

[Jim Campi]

Thanks Shawn for the detailed reply.

I set to record raw GNSS data. I believe there is a setting at the end of a setup configuration that always stores raw data. Do we need to select this option? Is this what you are referring to by "force the system"?

Also I only have the option to store a PPKs when there are no fixed epochs. How do I change this so I always have the option? I presume there is no setting to select on a point by point basis...rather we select to always record raw data as mentioned above. Is that correct?

 

[Nate The Surveyor]

Shawn said:
"so I force the system to always store raw data for those points, then I'm not worried about whether APP works or not"

APP is what automatically stores raw data, AFTER 5 mins.
So, the FORCE raw data, means that even for a shot of 1 minute duration, (out in the open) then it will have raw data.

Correct me if I'm wrong, but I think I have it right.

Nate

 

[Shawn Billings]

Yes. but this is only for my control profile which I have set to a minimum duration of 180 seconds. Having said that, in the open a 1 minute file would very likely be enough time for DPOS to solve a position from a nearby base (within a couple of miles).