NAME

relsen -- Calibrate the relative sensitivity of apertures.

USAGE

relsen intable outtable type ref_aper

DESCRIPTION

Calculate the sensitivities of apertures with the same filter relative to the reference aperture, i.e., count rate relative to that obtained at the reference aperture. Input data must have the same target, use the same filter, be of the same source type (point or extended), and be obtained at roughly the same temperature and epoch.

In this task, the observations made at the reference aperture are averaged, and then each observation made at another aperture is compared with this average count rate. When more than one set of measurements is made from the same aperture, the measurements are not averaged so that epoch identities are preserved.

Before actually performing the calculation, the raw digital count rates must be corrected for dark signal, pre-amp noise, high voltage factor, and dead time according to the following equation:

        scaled digital count rate = (raw digital count rate /
                (1. - raw digital count rate * dead time) -
                dark signal - pre-amplifier noise) /
                high voltage factor

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

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).
'TRGTNAME'      Target name (char*20).

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 produced by relsen; this table will contain the following columns:

'APER_NAME'     Aperture name (char*10).
'TRGTNAME'	Target name (char*20).
'SENSITIV'      Relative sensitivity (real).
'SENSITIV_ERR'  Error of the sensitivity (real).
(temp_key)      Temperature; the actual column name is passed 
                from the 'temp_key' parameter (real).
'EPOCH'         Epoch (double).
'TYPE'          Data type (char*7).
'PTSRCFLG'      Point source flag (char*1).

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

Input data type.

ref_aper [file name]

Reference aperture table name. This table specifies which aperture is the nominal aperture for a specific filter name and has the following columns:

'FILTER_NAME'   Filter name, e.g., 'F551' (char*4).
'REF_APER'      The nominal aperture name (char*10).

(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 indicating the name of the file in which the scratch table was stored.

(temp_key = "DET_TEMP") [string]

Column name of the temperature in the input table.

EXAMPLES

1. Calculate relative sensitivities from the input data table xrelsen$input and put the results in the output table yrelsen$output while saving the intermediate result in another local table, whose name will be announced to the user. Digital data is used. The reference aperture table to be used is xrelsen$ref_aper.

hs> relsen "xrelsen$input" "yrelsen$output" "digital" "xrelsen$ref_aper"
	save=yes temp_key="TEMP_DET" 

BUGS

REFERENCES

SEE ALSO