NAME

darkv -- Calculate the dark signal of each individual dark observation.

USAGE

darkv intable outtable type

DESCRIPTION

This task calculates dark signals from dark observations data. For the four image dissector tubes (IDT's), these dark observations are readings obtained at dark apertures which are spots that do not correspond to real aperture openings. For the photomultiplier tube (PMT), dark observations are observations of the sky where no target is in the field of view. This task operates on only one data type at a time. If observed data have both analog and digital data, then the task must be run twice. If the data type is digital, then the raw data will be corrected for pre-amp noise as follows:

        scaled digital count rate = raw digital count rate -
                                        pre-amplifier noise

        scaled analog count rate = (raw analog DN - CVC offset) /
                gain factor - pre-amplifier noise

PARAMETERS

intable [file name]

Name of the input table. The following columns are needed:

'DETECTOB'      Object detector ID (int).
'APERTOBJ'      Object aperture name (char*10).
'VOLTAGE'       High voltage setting (real).
'VGAIND'        Gain setting (real).
'THRESH'        Discriminator setting (real).
'DET_TEMP'      Detector temperature (real).
'DEA_TEMP'      DEA temperature (real).
'EPOCH'         Epoch of observation (double).
'PTSRCFLG'      Point source flag (char*1).

For digital data, the following columns are also needed:

'DOBJ'		Digital count rate (real).
'DOBJ_ERR'	Mean error of digital count rate (real)

For analog data, the following columns are also needed:

'AOBJ'          Analog reading (real).
'AOBJ_ERR'      Mean error of analog reading (real).

outtable [file name]

Name of the output table created by darkv, which will consist of the following columns:

'APER_NAME'     Aperture name (char*4).
'VOLTAGE'       High voltage setting (real).
'TYPE'          Data type (char*7).
'DARK'          Calculated dark signal (real).
'DARK_ERR'      Error of the dark signal (real).
(temp_key)      The temperature; the actual column name 
		is passed from the 'temp_key'
		parameter (real).
'EPOCH'         Epoch of observation (double),

type = "digital" [string, allowed values = analog | digital]

Input data type.

(cal_tables = "") [string]

Pset name for calibration file parameters. Parameters can be individually changed from the command line or can be edited as a group using :e from eparam or from the cl, eparam cal_tables or simply cal_tables. Details about these parameters are available by typing "help cal_tables".

(save = no) [boolean]

Save the scratch table containing intermediate calibration corrections? If save = yes, a message will be sent to the terminal and the logfile.

(temp_key = "DET_TEMP") [string]

Column name in the input table where temperature data is stored.

EXAMPLES

1. Calculate dark signals from the input data table xdarkv$input and put results in the output table ydarkv$output while saving the intermediate result in another local table whose name will be announced to the user. The data type in the input table is digital.

hs> darkv "xdarkv$input" "ydarkv$output" "digital" save = yes

BUGS

REFERENCES

SEE ALSO