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petff axe


NAME · USAGE · PARAMETERS · DESCRIPTION · FILE_NAMING_CONVENTION
EXAMPLES · TIME_REQUIREMENTS · BUGS · REFERENCES · SEE_ALSO

NAME

petff -- flat field the contents of a Pixel Extraction Table (PET)

USAGE

petff grism config

PARAMETERS

grism
Name of grism/prism image.
config
Filename of grism/prism extraction configuration file.
(back = no) [boolean]
Specify whether or not to apply the flat-field (FF) to the background Pixel Extraction Table (BPET).
(ffname = "") [string]
Name to use for the output flat field cube file instead of the default.

DESCRIPTION

This tasks uses a flat-field calibration file to flat-field the content of a Pixel Extraction Table (PET). The wavelength of a pixel is used in conjunction with a flat-fielding data cube containing the coefficents of a polynomial which can be used to compute at each pixel (x,y):


        FF(x,y,lambda) = a_0(x,y) + a_1(x,y)*lambda + .. +a_i * lambda^i

The coefficients a_0(x,y) are stored in the first data extention of the flat-field cube, a_1(x,y) in the second, etc... The name of the flat-field cube is read from the aXe configuration file.

Note that that flat-fielding should be applied to both the OPET and the BPET separately so that, when subtracted, the information contained in the BPET has been flat-fielded with the same flat-field as the OPET (which contains counts of objects plus counts from the background).

FILE NAMING CONVENTION

aXe tasks use default names for input and output files based on the given name of the "grism" image. For this task the default input PET would be called <grism-rootname>_<science extension>.PET.fits and will be flat-fielded "in place" using the flat field cube defined in the main configuration file.

EXAMPLES


        ax> petff test_grism_1.fits SLIM.conf.test.0

Perform in-place flat-fielding of the PET associated with the grism data file test_grism_1.fits. Use configuration parameters from the file SLIM.conf.test.0.

TIME REQUIREMENTS

BUGS

REFERENCES

Refer to manual for more detailed information about using this aXe task:


http://www.stecf.org/instruments/ACSgrism/axe/

SEE ALSO

petcont,pet2spc


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