APOLLO data reduction scheme

  1. Establish log file to record progress and parameters relating to reduction procedure
  2. Check for instances of CPS (counts per second) errors and log exceptions (also terminal warning)
  3. Check for consistency between TWS and FRC values for every event to make sure no clock ticks are missed. Log exceptions and warn on terminal.
  4. Perform polynomial prediction check against TDC prediction value for each lunar gate. Log exceptions and warn on terminal.
  5. Check for missing FID fast-photodiode records & log exceptions, summarize as fractional loss.
  6. Report laser dropouts (lack of FID gate at expected time); summarize clusters of dropouts by when they happen and effective laser frequency (clusters on >10 sec timescales)
  7. Sort fiducial records into alternating classes, consistent with diffuser vs. attenuator. Use motorrps parameter to accurately predict expected fiducial times. May need to build in self-adjustment/correction.
  8. Fiducial arrays to be 2-d: channel and shot.
  9. Plot fiducial fast-photodiode raw TDC distribution.
  10. Report maximum recorded TDC values for both FID gates and LUN gates, as a way to track effect of gate width on TDC effective coverage.
  11. Plot distribution of non-corner-cube FID TDC records.
  12. Plot distribution of non-lunar LUN TDC records.
  13. Fit quadratic function to latest TDC calibration data.
  14. Apply TDC calibration to all calculations of all time residuals.
  15. For each APD channel and FID type, find clipped mean, mode, and Gaussian fit parameters for the fiducial records. Record parameter arrays in log file (worth subsequent study).
  16. Explore behavior of above characterizations as a function of bin size.
  17. Plot the fiducial distributions for each channel, along with the Gaussian fit and mean, mode.
  18. Report the bias for each channel: the difference between the diffuser fiducial and the attenuated fiducial measurements.
  19. Process lunar measurements as before, but with the full machinery of fresh fiducials and TDC calibration.
  20. Perform linear fit to lunar range residuals, as before, using minimum window, taking care to place window symmetrically for noise immunity.
  21. Explore fit of lunar profile using methods similar to those used for the fiducials. Perhaps even a correlation method that is insensitive to functional shape (e.g., asymmetry, diffusion tails, double-pulsing).
  22. Plot histograms of photon number per shot for both fiducials and lunars.
  23. Provide mechanism for dealing with strong-signal bias, and explore magnitude of bias as a function of high-signal cutoff.