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Changes between Version 9 and Version 10 of MOPS_diff_false_positives


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Timestamp:
Nov 13, 2012, 4:08:54 PM (14 years ago)
Author:
watersc1
Comment:

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  • MOPS_diff_false_positives

    v9 v10  
    4141
    4242
    43 These plots are the same, but showing the relations between diff_rm/diff_sn_m for the different diff images (the plot labels are incorrect; these are the M versions).  These measurements are somewhat less obvious than for the P versions.  Although the signal to noise ratios (diff_sn_p / mops_sn and diff_sn_m / mops_sn) are similar for the warp-warp diff detections of asteroids, the diff_rm is not as small as for diff_rp.  This is reasonable, as the minus source is assumed to have moved between exposures.  The stellar sources occupy the same SNR/R space as in the P version, as the same residual issues create the matches. 
     43These plots are the same, but showing the relations between diff_rm/diff_sn_m for the different diff images (the plot labels are incorrect; these are the M versions).  These measurements are somewhat less obvious than for the P versions.  Although the signal to noise ratios (diff_sn_p / mops_sn and diff_sn_m / mops_sn) are similar for the warp-warp diff detections of asteroids, the diff_rm is not as small as for diff_rp.  This is reasonable, as the minus source is assumed to have moved between exposures.  The stellar sources occupy the same SNR/R space as in the P version, as the same residual issues create the matches.  The MOPS cut on diff_rm may exclude objects with large shifts, and should probably be relaxed.  If a source has a small diff_rp, and diff_sn_p / mops_sn ~= diff_sn_m / mops_sn, then requiring that diff_rm be less than 9 can exclude faster moving objects.
    4444
    4545Warp-stack diffs are far less likely to have a correct minus source associated, as any objects moving through the warp field is unlikely to have been there during the frames used for the stack.  As a result, the S/N ratio for known asteroid objects has a large amount of scatter, indicating that a random minus source is being associated with these objects.