Trimble Business Center

 View Only

 Point Clouds and Scale Factors

tyler masse's profile image
tyler masse posted 11-25-2022 07:10
Hello Everyone

Using Trimble Business Center version 5.8 and an SX12 Scanner/Total Station.

I am trying to find information about point clouds and scale factors. Our office works mostly in GPS/Grid co-ordinates. When my predecessor, who is no longer with the company, started working with point clouds he did a course and the instructor told him all point clouds need to be in 1:1 ground scale jobs as a scale factor can not be applied to them. If I look online I see references to point clouds having a scale factor but am not able to find where I would view what that scale factor is. As a result we are running two files for each job, one with GPS shots and another for the scan and any total station shots we store with the SX12. It seems to me like this is unnecessary but I was hoping someone could help me with confirming that before we risk loosing a day in the field.

To put it differently. What I would like to do is create a UTM Zone 18 Job in the data collector. Set two nails, shoot them with gps then set up on one with the Sx12 and backsight the other then start scanning/surveying. Is this possible to do all in the same job?

Thank you.
Albert Olivier's profile image
Albert Olivier posted 11-28-2022 09:15
Hi Tyler

Have a look at this TBC Power Hour, I think you will get most of questions answered here.

https://geospatialresources.trimble.com/webinar/tbc-power-hour-point-cloud-scale-factors-when-theory-meets-practice-in-tbc

Regards
Robert Hoy's profile image
Robert Hoy posted 11-28-2022 17:24
I always scale my projects to Ground values before I export to civil3d, including SX10 scans.   You don't mention using TBC, do you use TBC?  I presume you do since you have a SX12, and it'd be pretty wasteful not to use TBC for scan data.  Applying a scale factor in Local Site settings will scale all your observations including point clouds from SX10/12. 

If you export RCP point cloud files to civil3d you'd then want to choose "grid" so that the export isn't scaled again.  Then there's the feet/international feet scale that would need to be added in civil3d when you attach the RCP file so it lines up with survey points.