Altum thermal processing problem

Hi, we recently started using an altum on our rice paddies and use the thermal for monitoring various stresses. One of the first flights processed worked well but when I processed some flights a few months later the thermal had very poor results, with no definition in the image - flown at 35 m 75% overlap. I spent quite a bit of time trying to figure out why and finally noticed that the earlier processing used “optimize relative rotation” for the camera model setting, it chose this automatically upon loading the images, with the document icon :page_facing_up: next to it . Later processing always defaulted to the “optimize relative rotation using a subset of secondaries” which ran much faster but with poor thermal results. I edited the camera model to set it to the “optimize relative rotation” option and saved it, now with a pen icon :fountain_pen:, reprocessed steps 1-3 and now the thermal looks good. Why is the slower processing option required to get a good thermal result? Would it still provide a good result but speed up if I selected fewer image groups in step 2, currently defaults to include all imaging groups?

Hello @sklassen, The resolution of the thermal Altum camera is low in comparison to the other available thermal camera so the quality of the result might not be great. It would also depend on the texture and the area you are mapping. The only suggestion, that I would give is flying higher and with higher overlap so that there will be more key points for better calibration and quality. The recommended overlap would be 85% front and 80% side and the flight height of 45m or higher.
I would also suggest you to upgrade your software to 4.7.5 because in this version some improvement on processing the thermal rig was done.

In follow up, I did some testing and it’s clear that the camera model needs to be set to to “optimize relative rotation”. However, step 2 is fine using only the green camera for the point cloud and mesh geo which helps to reduce the processing time. Now that I have edited the camera model it comes up as the default setting. I then created a template that only uses the green camera for step 2 point cloud and mesh geo since this defaults to all cameras.

1 Like