Calibration Access and Data Handbook

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This CCF component is used by the SAS. The radial PSF distribution of the filter FilterId is tabulated in the extension PSF-FilterId. Azimuthal symmetry is assumed.
There is one extension per non-dispersive filter element and two extensions for each grisms. Thus in total there are 12 other binary table extension in the PSF1DRB CCF component, with the names:

PSF1DRB extension comment
PSF-U radial PSF of U-filter
PSF-B radial PSF of B-filter
PSF-V radial PSF of V-filter
PSF-UVW1 radial PSF of UVW1-filter
PSF-UVM2 radial PSF of UVM2-filter
PSF-UVW2 radial PSF of UVW2-filter
PSF-WHITE radial PSF of WHTIE-filter
PSF-MAGNI radial PSF of magnifier
PSF-GRISM1 radial PSF of UV grism 1st order (TBC)
PSF-GRISM2 radial PSF of visible grism 1st order (TBC)
PSF-GRISM10 radial PSF of UV grism 0th order (TBC)
PSF-GRISM20 radial PSF of visible grism 0th order (TBC)

In the photometric calibration analysis a fixed aperture for each filter is used to extract the source counts. The value of the cumulative PSF is normalized to 1.0 at this fixed aperture radius. The aperture radius is listed for each filter elements in the keyword APERTURE. The integrated flux within the radius APERTURE. is defined to contain 100% of the source flux. The aperture radii in the analysis of UV data are generally larger than in the visible. Therefore the aperture radius is listed separately for each filter in the keyword APERTURE of the filter extensions.

The stretching of the PSF as function of field position is described as function of the distance r between the detector location (x,y) and the boresight, i.e. as function of


. The functional form is a third order polynomial in r (cf. section 3.5.9). The parameters of the third order polynomial are stored as keywords in the extension headers.

In the binary extensions the radial PSF at the central detector position of the specified filter is stored as integrated intensity (column INTENSITY) between the radial bins RMIN and RMAX. The PSF is stored for different count to framerate ratios (column CFRR).

The binary extensions have the follow structure:

Binary table: PSF-FilterId

keyword keyword keyword keyword comment
name type unit value comment
APERTURE E pixel varies aperture radius of photometric calibration
PARX0Y0 E not applicable varies  
PARX1Y0 E not applicable varies  
PARX2Y0 E not applicable varies  
PARX3Y0 E not applicable varies  
PARX0Y1 E not applicable varies  
PARX1Y1 E not applicable varies  
PARX2Y1 E not applicable varies  
PARX0Y2 E not applicable varies  
PARX1Y2 E not applicable varies  
PARX0Y3 E not applicable varies  

column name column type column unit comment
CFRR E counts/frame/resolution element count to framerate ratio
RMIN 20E subpixel lower radius limit of bin
RMAX 20E subpixel upper radius limit of bin
INTENSITY 20E not applicable intensity in [RMIN,RMAX]

next up previous contents
Next: Generation from Ground Calibration Up: PSF1DRB Previous: PSF1DRB   Contents
Michael Smith 2011-09-20