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  1. Find and kill the stray light source. But we can't go back in time and do that, so instead just cut off y<500 from the frames, to make things cleaner
  2. compute the median of all columns and subtract that from each column, to get rid of the horizontal streaking
  3. Either smooth the image with a Gaussian kernel with sigma~3 pixels to account for residual Bayer pixel artifacts and fragmentation of the PSF
  4. run a source detection code with a fairly high threshold of significance, and then select out the bright sources that have centroids near where we expect them. 
  5. compute mean of all 7 centroids, call that the 'average position' of all 7. That is the origin of the center-of-spots coordinate system.
  6. Compute the mean position of each spot in that new coordinate system. This accounts for boresight jitter.  
  7. For each frame and for each spot , subtract that average from each of the 7 positions, which is differential motion of each spotoff that mean-spot-position. This is the instantaneous offset of each spot. It's a 2-d vector
  8. For each pair of spots (i,j) in each frame, compute the vector difference r_i-r_j of their instantaneous offset vectors. Compute the norm of that quantity. If spot motions are 100% correlated, this quantity would be zero. 
  9. Plot this magnitude-of-offset-difference vs. separation
  10. I'd also compute the mean intensity for all 7 spots, and take the ratio of each spot's intensity to that mean. This will let us look at scintillation as well as image motion. 
  11. Put the results into some sensible data structure(s)

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