- 14.23.1 Product PP2FOOTP: PHT-P2 footprint matrices
- 14.23.2 Product PP3FOOTP: PHT-P3 footprint matrices
- 14.23.3 Product PC1FOOTP: PHT-C100 footprint matrices
- 14.23.4 Product PC2FOOTP: PHT-C200 footprint matrices

14.23 Footprint Matrices for PHT-P and C

Description Parameter: none Processing Level: none, service to observer Usage in processing: N/A File Type: FITS Image File names: PP2FOOTP, PP3FOOTP, PC1FOOTP, PC2FOOTP

Using a model for the primary mirror, secondary mirror and tripod, the
theoretical point spread function (PSF) was obtained assuming a given
wavelength.
By convolving the PSF with the geometrical properties of the apertures
and detectors, synthetic * footprints* or * beam profiles* were
derived for each filter. The footprints are monochromatic assuming the
reference wavelength of the filter.
The footprint matrices give at each listed position the fraction of the
total power in the PSF falling on the aperture or pixel if the geometrical
centre of the aperture or pixel is placed at position (0,0). The matrices
are aligned with the spacecraft Y and Z-directions.

The high degree of asymmetry found in the measured P1 beam profiles cannot be explained with the present model. It has been decided to postpone the release of synthetic P1 footprints until a refined understanding of the P1 beams is available.

The footprint matrices can be used for accurate photometry in maps, e.g. for extracting accurate point source fluxes from an underlying extended component or in crowded fields.

14.23.1 Product PP2FOOTP: PHT-P2 footprint matrices

NAXIS = 4

TYPE = R*4

AXIS Length Description 1 2 Filters (20, 25m 2 14 Apertures (Change Wheel position) 3 87 Y-direction - steps for apertures steps for apertures 4 87 Z-direction - steps for apertures steps for apertures

14.23.2 Product PP3FOOTP: PHT-P3 footprint matrices

NAXIS = 4

TYPE = R*4

AXIS Length Description 1 2 Filters (60, 100m 2 14 Apertures (Change Wheel position) 3 87 Y-direction - steps for apertures steps for apertures 4 87 Z-direction - steps for apertures steps for apertures

14.23.3 Product PC1FOOTP: PHT-C100 footprint matrices

NAXIS = 3

TYPE = R*4

AXIS Length Description 1 7 Filters (C100, in wheel position order) 2 35 Y-direction - steps 3 35 Z-direction - steps

14.23.4 Product PC2FOOTP: PHT-C200 footprint matrices

NAXIS = 3

TYPE = R*4

AXIS Length Description 1 5 Filters (C200, in wheel position order) 2 35 Y-direction - steps 3 35 Z-direction - steps