quality

quality

stsdas.hst_calib.hrs.z_calib

quality

NAME · USAGE · DESCRIPTION · PARAMETERS · EXAMPLES · BUGS · REFERENCES
HELP · SEE_ALSO

NAME

quality -- Generate GHRS diode quality image.

This task updates a data quality image by locating dead diodes in a diode response image (specified by the diodemap parameter) and noisy diodes in a dark count image (specified by the dark parameter). Diodes are considered dead if the input diode response in diodemap is less than the threshold value dthresh. Diodes are considered noisy if the input dark rate in dark is greater than the threshold value nthresh. Both dthresh and nthresh are specified by the user. Only the 500 diodes on the main diode array are evaluated by this task.

An output data quality image of length 512 is created by taking an optional input data quality image and placing a value specified by dflag in locations of dead diodes and by the value of nflag in locations of noisy diodes. If a diode is determined to be both noisy and dead, then the flag having the higher value (the more serious condition) is used. All flags in the input data quality image are retained in the output data quality image. The data quality value in the input image is never replaced with a lower data quality value.

PARAMETERS

diodemap [file name]: Name of the input diode response image. This file is generated by the diodemap task.

dark [file name]: Name of the input image containing the dark count for each diode. This file is generated by the parthitz task.

dqin [file name]: Name of the input data quality image to be updated. This image must have a length of 512 (i.e., one element for each diode).

dqout = "dqout" [file name]: Name of the image containing the updated data quality image; this image has a length of 512 elements.

(nthresh=0.01) [real]: The threshold for identifying noisy diodes in the dark image. All diodes having a dark rate higher than nthresh are flagged as noisy diodes.

(nflag=10.0) [real]: Value used in the data quality image dqout to flag noisy diodes.

(dthresh = 0.2) [real]: The threshold for detecting dead diodes. Diodes having a response lower than dthresh are flagged as dead diodes.

(dflag=20.0) [real]: The value used in the data quality image dqout to flag dead diodes.

EXAMPLES

1. Update the data quality values in the image dq1 using the diode response image dmap and the dark rate image dark. Flag those diodes having a dark rate above 0.005 counts per second as noisy. Place the updated image in a image called dq1a.

hr> quality dmap dark dq1 dq1a nthresh=0.005