| | 1 | == February 15, 2012 == |
| | 2 | |
| | 3 | === False Positive rates === |
| | 4 | |
| | 5 | Nigel sent around an image made by Peter showing the results of psphot on the new footprint g stack. Left shows the old results, and the right shows the new. This shows that there are significant improvements (quoting the email: "The number of false detections has dropped by about 40% at g~23.5 (CAL_PSF_MAG), which is good, although they are still higher than the number of matched (to Stripe82) detections faintward of g~23.4."), although stripes of false detections are still visible. I suspect some of the remaining concentrations are caused by corner glows/dark features. |
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| | 7 | [[Image(falseold_new.jpg,800px)]] |
| | 8 | |
| | 9 | Independently of this, I've made quick DVOs of the individual exposures for each of the three reductions to see how many times an object is detected in the set of 12 exposures: |
| | 10 | |
| | 11 | [[Image(logcounts.png,800px)]] |
| | 12 | [[Image(ratio.png,800px)]] |
| | 13 | |
| | 14 | Assuming all single detection objects are false positives, the improved continuity correction is only removing about 10% of these false objects. |
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