Muxbleed Correction Threshold
Note: the following information is intended for the IRAC instrument team
only. If you are not such a person, you should not be reading this. No
guarantees are made as to the applicability of this information to the
real IRAC.
At some threshold it is pointless to evaluate the muxbleed correction
because it will be so small that it cannot be detected. The muxbleed
algorithm will also be much faster if it does not evaluate the correction
for every pixel. The module has such a threshold that can be set via a
namelist parameter.
To evaluate what threshold to use, I used the current coefficients and
lookup tables for channels 1 & 2 to compute the intensity of the
largest correction (which is always the pixel immediately following the
"bleeder") as a function of bleeder intensity.
| Ch. 1 |  |
| Ch. 2 |  |
The thresholds at which the maximum correction exceeds 0.1 DN are given
below. This value is approximately 30 times smaller than the read noise,
and should be a very conservative choice. The
muxbleed document produced by
Joe Hora actually indicates that the correction is probably negligible for
bleeding pixels below 10,000 DN.
| Corr(max) = 0.1DN |
| Ch. 1 | 1041 |
| Ch. 2 | 4301 |