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Messages - Lambertus

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1
General / Re: Large errors for yaw, roll and pitch?
« on: July 15, 2019, 03:21:14 PM »
Thanks for your reply. It is clear to my now :)
I managed to fix the issue using the GPS/INS window in the Reference pane.

2
Camera Calibration / Re: How to calibrate
« on: July 10, 2019, 05:45:41 AM »
Hi Minhazul,

I visited the webpage you posted. However there are different products listed. Which one do you mean?

3
General / Re: Large errors for yaw, roll and pitch?
« on: July 09, 2019, 04:56:25 PM »
Thanks for your quick reply.
I will share my project in PSZ format including thumbnails. Furthermore I will send my csv file with orientation data.

4
General / Re: Large errors for yaw, roll and pitch?
« on: July 09, 2019, 04:49:42 PM »
Hi Alexey,

Hello Lambertus,

Orientation angles are not included in the referencing procedure according to your screenshot (see the check box in front of Yaw angle in each row).

Thanks for your reply. I didn't know that I needed to check the boxes in front of the yaw column. I will try if checking these boxes will increase the accuracy of my model. 

When I loaded my raw aerial imagery into PS, I saw that some images were rotated and some not.  Outside PS I rotated all my images 90 degrees to the right, clockwise direction. After this I added my photos to PS. It seems that all images were positioned right yet. 

The camera position data including yaw, roll and pitch is not related to my manual rotation action. These yaw, roll and pitch values were attached in separate files to my aerial images. I combined them into one file and added this via Reference Pane.


Do the loaded Yaw angles properly correspond to the flight direction? 0 degrees in one direction and 180 degrees in the opposite?

As far as I know, these yaw angles correspond with the flight direction.

I have another question as well. I saw the reprojection error in the info of my chunk. Does a large error mean that a produced point cloud will totally mismatch when draping this point cloud on top of a correct aerial basemap?
(assumption: point cloud and aerial basemap have the same projected coordinate system)

5
General / Re: Large errors for yaw, roll and pitch?
« on: July 09, 2019, 04:44:46 PM »
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6
General / Large errors for yaw, roll and pitch?
« on: July 09, 2019, 10:05:56 AM »
Hi guys,

Currently I am working with aerial images trying to create a point cloud from a certain area in my country.
I imported my camera positions including yaw, roll and pitch. However, it seems that including yaw, roll and pitch increases the error in my model. See the attached image for more information. Should I exclude roll, yaw and pitch from processing maybe?  Thanks in advance for your help!


7
General / Use markers to correct shifted point cloud?
« on: July 01, 2019, 01:15:13 PM »
Dear community,

I want to create an georeferenced point cloud for vegetation analysis. The point cloud will be used to get information about the absolute height of vegetation.  I imported six oblique aerial images which overlap with my area of interest. The reference system of these images is EPSG 28992. I have set this one in the Reference pane. Furthermore I imported camera positions of each image (x, y, z, roll, pitch and yaw).

I set the camera type to 'Frame', focal length to 100.5 camera size to 0.006 mm x 0.006 mm.

Then I alligned my six aerial images. After that I optimized my camera. I got a RMS projection error of 0.06.

I continued with building a dense cloud (High accuracy, mild depth filtering, calculate point colors)
I exported the results as a las file.

I opened the las file in ArcGIS Pro and visualised it on top of aerial imagery background map referenced with coordinate system EPSG 28992 (RD New).

 It seems that the point cloud is not exactly I expected it to be. Locations with buildings for example, where I would expect higher elevation points were not represented well. The high elevation points were shifted for example approximately 5 m to the left and 3 m southward.  There seems to go something wrong..

Hence, I am thinking of useful solutions to get the point cloud in the right place:

- I am thinking of creating markers on my aerial images including x, y and z coordinates. At this moment I did not use markers in my Agisoft workflow. Maybe the referencing of my images will turn out to be better when using markers.

Do you have any suggestions about my workflow and how I can get put the point cloud in the correct place?
Do you for example have ideas how I can generate manually markers with x,y and z coordinates in QGIS or ArcGIS?

Thanks in advance for you help and reply!

This image shows the shift in north-west direction, the building is not represented completely. The grid shown is a 5m raster, dynamic scaling.



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