Extra time marks on M2

Hi Svetlana,

We have purchased 2 new RS2 units and 2 New M2 Units. With a bit of a struggle I have got a result from the RTK Lib Software.

I am faced with one problem though, I have 170 Images and 174 events. The problem is none of the events have odd times so cannot Identify which 4 events must be deleted.

I have deleted the first 4 and get an error in pix 4 d, I have deleted the last four and get an error in pix4d aswell.

I am not sure how to identify the problem events?

Hi Andrew,

May I ask you to share your raw data and events files with us? We can check the time spans between them and find out the time marks that should be removed.

You may have very close pair events (0.1 sec diff), that is easy to identify and remove the second ones.

Hi Pascal,

Thanks for the tip. There are alot of 00:00:00 times when deducting them from each other. When I delete these there are identical number of images to Events.

Appreciate the help

You are welcome, now validate the cleaning with a photo alignment calculation and check errors

Hi Tatiana,

Thanks alot. I have come right with the help of pascals comment below. Although I am getting allot of Q2 values. https://www.dropbox.com/sh/es5v6vqmx1o6mok/AABZdNrHXCaTiw1ZNWezH9X-a?dl=0

the base coordinate is -25.6965710864 28.5295842167 1514.9700.

I am not sure if I have some settings wrong in the RTK conv and RTK post.

Thanks for the response

Hi Andrew,

We’ll check your data and try to achieve better results on PPK.

Andrew,

Also, I’d recommend checking out this article on improving the PPK results.

Hi Andrew!

I’ve looked into your data and these are the results.

You can see the initial and the improved PPK results on the plots below. The initial solution had 41.9% of fix, the improved consists of 85.3 % of fix. Also, you can find the settings I’ve used: Combined Filter Type, Elevation Mask = 20, and standard SNR Mask.

I’d like to point out that the quality of the satellite signals observed by the rover could be improved. You can see a lot of cycle slips on the plot. Rover tracks only 3 satellites with SNR=45. This factor causes difficulties with obtaining fix solution.

May I ask you to share the photos of the hardware setup? They will help me to understand what can be improved for better performance.



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Hi Andrew,

We have some additional questions about the extra time marks issue you outlined.

In the logs you shared, we got 326 events. Are you sure it’s the same logs you mentioned in the first post?

Hi.

No the logs I sent were of a different flight.

I am trying to uploadthe images but am having a bit of a tough time. The internet access is not great our side.

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Hi @anastasiia.iusupova
Can you elaborate a little on this requirement?
I my reading I can only find that 40 dbhz is the value to go for.

Hi Christian,

Usually, we recommend working with SNR = 45, this ratio shows very good satellite visibility and working conditions.

However, SNR = 40 is normally okay to obtain fix status.

Shouldn’t the default in RTKLib reflect this? Right now the default SNR mask is 35?

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Hi Andrew,

It’d be nice if you have a chance to share the log as it helps us a lot in preparing the fix for the issue. The more data we have, the more tests we can do.

Also, would you mind sharing your hardware setup photos? It’s essential for us to see how you connected the M2 unit to a camera.

Thanks.

Most of the observations are not ideal, even if the signal has SNR > 40 in general, it may have areas where the SNR was less than this value.

Thus, the standard SNR mask allows you to not discard signals which on average have good quality.

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Hi Tatiana,

Apologies for the delay.

Our Internet is not great here and am struggling to get a data set uploaded.

Here is an image of the setup we have so long.

Will leave a comment as soon as I have been able to upload imagery.

Hi Andrew,

I’m back with some news. We’ve released the v2.22.5 stable update that should fix the issue with extra time marks on M2 devices.

It’d be nice if you have a chance to try it and let us know how it works.

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Also, I’d like to point out that this fix only works for logs recorded in RINEX currently.

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Hi Andrew,

We’ve just updated the RTKLIB version in our docs. You can now convert all your UBX logs using a new version and get the files with the correct time marks quantity.