Why do I get Different Results for Spot Analysis using Single Spot Analysis vs Multiple Spot Analysis?
You may notice that on an image when analyzing a spot that using single spot analysis and multiple spot analysis for the same spot may lead to slightly different results. The reason for that is the two analysis use different algorithms and inputs for their 1D Gaussian fit.
The multiple spot analysis will create one inline and crossline profile out of the entire ROI, by doing this it sums up the row entries for the profiles and creates a fit.
The single spot analysis algorithm will detect the spot inside the ROI by finding the pixel with maximum intensity, then it creates a profiles through the pixel with maximum intensity of the spot and creates a fit.
So in summary the two different analysis taks have slightly different algorithm criteria, that leads to different fits with slightly different results.
It is then important to make sure for your monthly and annual baselines to be consistent in which analysis you choose to make sure you are appropriately quantifying changes in your spots.