|
L1 photometry validation in 3band-cryo period | |
Three-band cryo frame extractions from v4.5 testing of the scan-frame pipeline were compared to the same sources extracted from the 4-band cryo phase of the mission (processed with v4.0). The following L1 source selection criteria were used for all three bands (independently):
match radius = 1 arcsec; w?sigmpro ne 'null; w?snr >= 3; w?sat = 0; 0.1 <= w?rchisq <= 3.0; cc_flags = 000 (for w1|w2|w3); nb = 1; na = 0; dtanneal >= 1200 sec (w3 only)
In all, 592704, 397720, and 6278 matches in W1, W2, W3 respectively
satisfied these criteria. We retained all (independent) L1 frame apparitions
from v4 corresponding to each v4.5 extraction.
 |
 |
 |
 |
See next plot for breakdown by exposure time.
 |
Same as above but broken down by v4.5 exposure time.
The approximate SNR ~ 5 limits were deduced (crudely!) from the w3snr vs w3mpro plot at the end of this document. For all exptimes, it appears the most deviant v4.5 magnitudes (relative to v4) are dominated by noisy v4.5 measurements. Note that use of SNR=5 (for L1 extractions here) is purely illustrative. We may want to go with a higher cut for the 3-band cryo catalog (which will be constructed from L3 data).
 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
 |