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The Height on GCP are identical to the RTK-Heights in Model but height error in the new points because of update to 4.0.25?

Hi,

the Update from 3.1.23 to 4.0.25 occures an height-error in the Calculation of the new points. The Error is not visible at the qualityreport. The drone and the input for the calculation ist the same as further. Why?

 

Greets,

Stephan

Hi Stephan,

could you upload some screenshots that show the issue you are facing?

Is the offset that you receive the same for all the points or it differs between points?

Best,

Hi Blaz,

thanks for response. Attached is the quality report. The GCP have small residuals but the new calculated points are wrong in height. The height offset is about 50cm but not exactly. The error gets smaller than nearer at the GCP. See the PDF with additional control points.

Thanks a lot.

Greets

Stephan

how can I upload the attachments?

You can use this link to upload the .PDF files: https://1drv.ms/f/s!AhrQbyoNK92LjEMq7SydhX1rHTe2 

I had a look at the Quality report and the .pdf with the control points and I could see the offsets you mention.

Could you let us know what do you use for comparison of the project with the control points (point cloud, DSM, …)?

Do you notice some offset when using the outputs of 3.1.23?

Hi,

for the comparison i used GPS-Points generated with my differential GPS. (Surveyor-Equipment).

In former days when I used 3.1.23 the results were right with the same programadjustments.

Please look for an fast result of the problem because my customers need the results.

Where can I get the old version 3.1.23 for download?

Greets

Stephan

What is the expected accuracy of the GPS system you are using? From what I understand, the differential GPS is not as precise as the RTK and could be the cause of the offset that you see when comparing the points.

Do you have some other points that you could use to do an independent check of the accuracy of the GCPs that were used in this project?

Hi Blaz,

 

please have no doubt relative to my RTK GPS. I use it daily and have control about the precision because I make residual surveying. The results of the flight are wrong. The error in height gets larger with the distance of the GCP.

Greets

Stephan

Could you also upload the original .p4d file and the text file with GCPs on the link that was previously provided?

Additionally, please upload the whole project on the cloud and I will have a look at what could cause the issue that you mention: https://support.pix4d.com/hc/en-us/articles/202558589.

Hi Blaz,

sorry but I have following error:

[Processing]: ProjectLoading

[Processing]: ProjectLoaded

[UI]: Upload Project Files clicked.

[Error]: Fehler e0502b:

[Error]: 

[Error]: Das Projekt 1878\_180919 kann nicht heruntergeladen werden.Projekt konnte nicht in der Cloud erstellt werden

[UI]: Settings clicked.  
  
  
How on?

Hi @Stephan,

the reason why you cannot upload the project on the cloud is that your Support & Upgrade has expired. The Support & Upgrade is giving you access to our dedicated Support, to all the software upgrade and new releases and to our Pix4D Cloud. Please, have a look at the article https://support.pix4d.com/hc/en-us/articles/360015867071-How-to-renew-support-and-upgrade to learn more.

EDIT :
Meanwhile, could you upload on https://1drv.ms/f/s!AhrQbyoNK92LjEMq7SydhX1rHTe2 the whole project files or at least:

  • the original .p4d file

  • GCPs file

  • input images

-control points, if present

Thanks,

Alice

Hi Alice,

thanks for the uploadlink but it do not funktion.

Greets

Stephan

We updated the link, could you give it another try?

Hi Stephan,

I had a closer look at the files you shared with us and there is no obvious reason why would the errors be higher on some points. The reconstruction was performed as expected and the results do not contain artifacts/noise.

We were not able to find the GCPs and images among the files and were not able to do the processing and comparison on our side.  I would recommend doublechecking if the equipment that was used for measuring the GCPs and checkpoints is properly working. It looks like the errors are bigger when the checkpoints are close to building and trees that can obstruct the GPS signal and therefore result in a lower accuracy of measurements.

Hi Blaz,

I´ve bought the 3d-pointcloud from the aerolaserscanning which was made from our bavarian ADBV. Its our bavarian department for geodata and cadastral land register. This data is ident with my GCP and with my controlpoints from GPS. If you reactivate the cloudaccess for me so I would upload this file in original version.

Greets,

Stephan

Hi Blaz,

the file from the ADBV is still uploadet to mydrive.

Greets

Stephan

There is a visible offset (approximately 0.5m) when comparing the uploaded file (ADBV) and the point cloud generated in Pix4D:

Could you please provide the following so I can run the process here in the office and finalize the troubleshooting: 

- the original .p4d file (1878_180919 .p4d )

- GCPs file that includes the coordinates (x,y,z) of the points that we can see were used in the project (180919001, 180919002, 180919003, 180919004, 180919005)

- input images (original 240 images used in the project)

- control points that were used for comparison (.txt file with coordinates).

 Files can be uploaded here: https://1drv.ms/f/s!AhrQbyoNK92LjEMq7SydhX1rHTe2

 

Hi Blaz,

the upload is still running but the space of the cloud is too small. The picturespace is 1,55GB. You still must have the pictures from the last upload. I send you the pictures from the end of the flight because these were not uploaded in further time.

Greets,

Stephan