Hi,
this is a topic discussed in the course, which I strongly suggest you to take. Generally, better not to estimate the thermal expansion at the APS processing stage. Instead, use a linear model and then estimate the thermal expansion in the MISP module. However, if your area is full of high buildings, (and if you cannot manage picking up points only on the ground) you might be obliged to include also the thermal expansion estimation in the APS module. If this is the case, you have to do this carefully. In any case, you can understand if you are doing things correctly by looking and judging well all outputs that Sarproz offers you during the APS processing. That’s why I suggest you to take the course.
Best