Georeferencing with coordinates of a scan origin

[gregg]

It's my first post on this forum so Hi to everyone :)

I want to georeference my cloud with coordinates of a scans origins which I got using RTN-GPS and a special adapter which allows me to attach antenna to the scanner. I do know that I can import these coordinates as a separate cloud ("reference" cloud) and than make a georeference by picking corresponding pairs of points but...how to pick or insert the origins to individual scans ("to align" cloud)?
Will I find such a possibility in a CloudCompare?


btw. A Big Thank You for your software Daniel!

[daniel]

Hum, there's no automatic way to export the sensor center as a point.

However, if you have the sensor information in your file (i.e. with PTX, FARO or DP files) and there are not too many sensors, here is what you can do:
- access the "sensor" parameters (below the cloud you should have a 'TLS/GBL' sensor entity) with 'Edit > Sensor > Edit'
- in the first tab (Position + Orientation) copy the sensor center (C = first row)
- Add one sensor center per line in a file (X Y Z)
- Save this file as a '.txt' or '.asc' file
- Open it in CloudCompare as an ASCII cloud
- If necessary merge it with the original cloud(s)

[gregg]

Unfortunately files generated by my scanner don't support sensor information such as position. In addition this position changes after alignment/registration of individual clouds.
btw. I'm using LAS format to import my data into CloudCompare.

Your solution would be sufficient for me but There is no way to read the coordinates of an origin from an individual cloud.

[gregg]

Hum, there's no automatic way to export the sensor center as a point.

However, if you have the sensor information in your file (i.e. with PTX, FARO or DP files) and there are not too many sensors, here is what you can do:
- access the "sensor" parameters (below the cloud you should have a 'TLS/GBL' sensor entity) with 'Edit > Sensor > Edit'
- in the first tab (Position + Orientation) copy the sensor center (C = first row)
- Add one sensor center per line in a file (X Y Z)
- Save this file as a '.txt' or '.asc' file
- Open it in CloudCompare as an ASCII cloud
- If necessary merge it with the original cloud(s)

As I'm staring with Cloud Compare - at first I did only import 2 scans and didn't notice that all of them have origin set in [0, 0, 0] :) In this case I'll will follow your suggestion and add point of origin in every individual scan, than merge them, perform registration and finally georeferencing with my GPS coordinates :)

Thank you!