The DSM output from Pix4Dmapper was generated not correctly

PIX4Dmapper PIX4Dmapper Questions/Troubleshooting
1

Dear nice Supporter

First of all, My device are

-DJI Mavic 2 Pro
-Flight by Pix4D Capture
-Process in Pix4D mapper
-Open data in ArcGIS

My problem is sometime I got the abnormal DSM file form Pix4Dmapper., almost time not all
DSM layer have the low value around center of the map event that area is flat, sample quality report as bellow

image
image774×618 218 KB

Then I open the DSM file in GIS Program the result show like this

image
image1212×606 366 KB

It quit too much different value of height (10 meter dif). I try to re-process more than one and the result are same.

Could you please suggest me what is the cause and how I can solve this.

Thank you in advance

Best
Tony

2

Hi Tony,

This is in deed surprising. Could you please share your entire quality report?
Maybe there is something we can do by changing the processing options.
However the best would have been to use GCPs.

Best

3

Sure, Here is my report.

2020-02-27-kc01_report.pdf (2.5 MB)

Anyway, I try to use 3DGCP by apply x y z(elevation) number from the GarminGPSmap 62 model then the result look like better than without use, but the elevation value in DSM output is difference from GCP’s Z value at the same position.

I think I have read manual and follow step by step when I use GCP.

Best

4

Hi @vorraveerukornv,

From your quality report, there is not much I can say. The calibration went quite well.
Do you have the quality report with the GCPs included?

My guess is that you have been flying very high and as the resolution of the Mavic is not so high you get this pattern. However we can see it:

image
image1031×161 21.6 KB

Could you try to upgrade to the latest Pix4Dmapper version?
In the past, there have been some issues with the mavic. This might help.
My last suggestion would be to change from Rolling Shutter to Linear Rolling shutter in the camera edit window.

Best

5

Hi @Pix4D_Alumni_MV

I will attach GCP’s quality report soon, I re-processing again because I already delete it (storage problem).

I quite agree with you in case of my level of fly very high, 150 meter above ground is normally I have fly.

So I will try to reduce the high and looking for result again.

About my software version,

I use Pix4Dmapper Pro version 3.1.22, license type is One-time charge so I think I cannot upgrade to any new version, In the past I used to upgrade to 3.2.33 version but my user and password cannot open the software or cannot running some tool well or something as I can remember.

So, now can I upgrade my software to new version and still can use it any tool the same?

Best
Tony

6

Hi,

In deed if you have an OTC without Support & Upgrade, you cannot download the latest version. You would need to buy it.
In my opinion the pattern you see is related to your flight height.
This bug was reported for the Mavic 2 Pro:

And it has been solved in 4.4.9.
However it does not seem to affect your project.

I would expected that flying lower you should be able to get proper results and avoid this pattern.

Best