BenEngebreth.org

Dynamic Sky: Process Description

This is a descriptive outline of the process I use to detect solar system object motion from repeat imaging. The process is constantly evolving but is more or less accurate for the object it references.

Sedna

  1. Acquire TESS full frame images
  2. Crop full frame images to region of interest
  3. Integrate images into a set of analysis frames (e.g. median of N full frame images around a time for each day)
  4. Model and remove background from analysis frames
  5. Reject outlier frames (e.g. frames with outlier medians compared to other frames after background subtraction)
  6. Deconvolve PSF for each frame
  7. Brightness match frames to a preliminary template (e.g. the median of the frames) to complete initial processing
  8. Generate a bright star center mask from median template via sigma clip
  9. Generate static sky templates as 1 pixel trimmed max of the stack of processed frames down to the median (N/2 pixel trimmed max)
  10. Subtract each static sky template from processed frames to generate difference images and keep difference image that has the highest frame median pixel value to standard deviation ratio (SNR-like)
  11. Apply bright star center mask to difference images
  12. Threshold difference images
  13. Link detections in threshed difference images using pixel velocity vector clustering
  14. Match linked detections in threshed difference images to JPL expected locations

(208996) 2003 AZ84

  1. Acquire TESS full frame images
  2. Crop full frame images to region of interest
  3. Integrate images into a set of analysis frames (e.g. median of N full frame images around a time for each day)
  4. Model and remove background from analysis frames
  5. Reject outlier frames (e.g. frames with outlier medians compared to other frames after background subtraction)
  6. Deconvolve PSF for each frame
  7. Brightness match frames to a preliminary template (e.g. the median of the frames) to complete initial processing
  8. Generate static sky template as trimmed max of the stack of processed frames
  9. Generate a bright star center mask from static sky template via sigma clip
  10. Subtract static sky template from processed frames to generate difference images
  11. Apply bright star center mask to difference images
  12. Reject outlier difference images with too much noise
  13. Threshold (and optionally remove small objects) in difference images
  14. Link or match objects in sequential threshed difference frames

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