PPK point extractor software

We can write a translator of pos to SQLite database and connect it to QGIS. Then you can write SQL queries in many ways straight in QGIS (as far as I know, it is possible).

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Really nice little tool you have here. Just wanted to put in for 2 more features for when you have finished up your thesis:

Colour coding this section should be similar to the dots on the edit panel.

i.e. only green for a fix, yellow for a float, red for a single etc. Not coloured means that it hasn’t been processed.

The CSV that it saves doesn’t actually save as a csv, it is using a semi-colon as a delimiter (or at least the version I am using 0.2.1 on windows) and it would be great if it also provided the point statistics in the CSV, specifically the ratio of Q1/Q2/Q5 so I can then filter the resulting CSV for anything that isn’t a fix.

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Could you make the application of the time in UTC and GPST? it would help us to process PPK
when it makes the correction from UTC to GPST it does not add up to 18 seconds

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There is an option to apply these corrections. I answered on your question in another thread.

This is pretty dang awesome!
Noticed a few bugs:

  • No RMS for each PPK point reported or written to file
  • When reviewing each position manually, pressing “Filter pos” will make the height-chart add 1 more graph pr mouse-click.

Could I contribute somehow with a donation ?

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Yes, I know about this bugs. Still didn’t have quite much time to solve them and push a new version. I also don’t like the fact, that such simple application is more than 200 Mb! Node.js seems to take a lot of space with the modules.

It is very kind! I wasn’t thinking about it, maybe in the future. :wink: It is my pleasure to help our community.

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Hi, @jurijs.jeshkins I found a difference in the average it does with the pos file that is not equal to the fixed point. What I do not understand that if I take 20 fixed points with rechview the result of the final coordinate is the arithmetic average? With the extractor point do you average the points Q = 1 of the pos file? instead of an average, the ideal would not be least squares or a weighted average? I know it will be a lot of work. What if I repeat again that there is a coordinate difference when using bach processor. Thank you


The coordinates of a fixed point must be equal to that processed with Point Stractor and it is not. applied correction because the pos file is in GPST and the points file in UTC. You should review this difference or then the rechview does not average

Hi!

You applied correction with RINEX to your observations? Can you describe briefly your setup and measuring methods?

Hi @jurijs.jeshkins RTK measurement of points for 20 seconds not UAV. I do data processing in Rtklib kinematic base and Rover to get the pos file and then read it from Point Stractor. I did the test with fixed points that when using Point Stractor should be the same! That’s why I think that the coordinate of the rechview that you save in the csv is not an average because it should be the same

I don’t quite understand your workflow. Correct me, if I am wrong:

You have 2 units, one as a rover and another one as a base, right? You obtained RINEX from both units and corrected it in RTKlib (rover correction against base RINEX). But, during the measurement, you had also RTK, that was supplied by your base. So, in your CSV file you have points, that are corrected via RTK, but in your pos file, you have PPK. And the averaged solution of PPK point extractor is different from what you see in CSV file (averaged by ReachView). Am I correct?

This correct

I don’t know exact algorithms, how ReachView averages, and which points it uses (only FIX or all points). For now, PPK point extractor uses all points to average the location.

I think it might be a good idea to filter the points by their ar ratio, I do that within my script. Then my points (static pkk calculation) do differ by some mm at most - so averaging has almost no effect (that is why I did not look into your sofisticated centroid solution) - but I did not compare it to the calculations done during the survey.

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You should only average the fixed positions Q = 1, in a 5 minute interval (PPK) there should be measurements with Q = 1

@tobias-dahms if I compare the Rtklib file it gives me the same coordinate I said and it only varies very little as you say

I think you could even average the points with the highest ar ratio.
What do you mean with a 5 min. interval? I measure my points for 120 seconds. I think if you need a better result must do it for several hours?

float is 5 minutes and single 15 minutes kinematic observation! Stop & go (ppk)

If you can filter only Q=1 points in RTKlib, you can save them as pos and extract points from PPK point extractor.

I would have to edit the pos file and leave only the points Q = 1, what do you mean?