Cloud Measurement Incorrect Area and Distance

PIX4Dcloud PIX4Dcloud Questions/Troubleshooting
1

I did a flight of 20 cleared acres and when I do an area take off in cloud it reads 203 acres.  I pull a distance that reads 100 yards and it is max 100 actual feet on ground.   Can you please explain how to correct or explain what I or you are doing wrong please.

 

 

Ryan Lynch

2

Hi Ryan, 

Can you share the link to your cloud project? Click “Share” in the top right corner and paste the link as a comment in this post.

Maybe something went wrong during the processing. If you share the link I can have a look at the project and  the quality report. 

Thanks!

3

Hello,
Thanks for your work, Pix4D cloud is simple and full of potential!

I have one precision issue’s with a result. We compared the pix4Dcloud result with a traditionnal geometer result and what can we say is :

  • The X,Y precision is good
  • The elevetion is not good (at all). half meter imprecision

Does it cause due to pix4D dataset or maybe the acquisition (I will do it again with GCPS)?

4

Hello everyone,
I am currently facing an issue regarding merging two models.

  • The first model was built with low resolution non-georeferenced aerial images covering a large area. These images were uploaded to the website of the Institute for Geographic and Forest Information (IGN). This model was then well geolocated in space by adding GCPs in WGS 84 / UTM zone 31N.
  • The second, smaller model was built with good resolution, georeferenced, drone acquisition images taken during a field mission. The latter was initially geolocated.
    Now I have tried to merge these two models in order to get a more complete model. The result obtained after the initial treatment was quite satisfactory. However, the two other treatments, namely point cloud densification and triangular meshing, do not work in the study area except for the coverage area of the 2nd model (smaller).
    Now I would like to know Can we merge two models of different resolution, and different coverage area ??
    Can we merge a model initially georeferenced in space with another model initially not geolocated but which was then georeferenced?
5

Hello Nanaba,
Yes, you can merge two projects that have a different resolution, however you must follow these guidelines:

Two or more projects can be merged only if ALL of the following conditions are fulfilled:

  • The coordinate system (both horizontal and vertical) of the images has to be the same in all subprojects. Note: A subproject with no image geolocation can be merged with a subproject with image geolocation.
  • The GCPs have to be in the same coordinate system (both horizontal and vertical) in all subprojects. Note: A subproject with no GCPs can be merged with another subproject with GCPs.
    It is highly recommended the GCPs to be added in the merged project, especially when more than 2 subprojects are merged.
  • The output coordinate system (both horizontal and vertical) of all subproject has to be the same. Note: A subproject with no georeference (arbitrary system) can be merged with a subproject with georeference.

For more information about the Image / GCP / Output Coordinate System: How to select / change the Image / GCP / Output Coordinate System.

6

Hello Mike_K,
Thanks for these informations. I had already followed these steps but the model was not working. It would have been necessary to take a smaller area around the 2nd model for it to work.
Thanks for your help.