Subsections

• 14.21.1 Product PPOMEGA: aperture dimensions and solid angles for P1, P2, and P3
• 14.21.2 Product PC1OMEGA: dimensions and solid angles for C100 pixels
• 14.21.3 Product PC2OMEGA: dimensions and solid angles for C200 pixels

14.21 Effective Solid Angles of Apertures and Pixels

Description Parameter:	 Sections 4.5.1,  5.2.5 and 5.3
Processing Level:	 AAR
Usage in processing:	 Section 8.4.7
File Type:		 Binary FITS Table
File Names:		 PPOMEGA, PC1OMEGA, PC2OMEGA

In the conversion from flux per pixel or per aperture (in Jy/beam) to surface brightness (in MJy/sr) the effective solid angles ${\Omega}_{eff}$ are required. In the present set of Cal-G files, the effective solid angles were obtained from a model calculation which takes into account the ISO primary mirror, secondary mirror, tripod, and the linear sizes of the apertures and the detectors as measured pre-flight.

The Cal-G files also contain the dimensions of the apertures (in case of P1, P2, and P3) or the offsets and dimensions of the detector pixels (in case of C100 and C200) as projected on the sky in arcseconds. Fields for the uncertainties of all parameters are included.

The Cal-G files related contain the following limitations:

• all uncertainties have been set to zero,
• the effective solid angles of the PHT-P apertures are the physical dimensions of the apertures in the focal plane projected on the sky.

In case the PHT-P aperture areas (in mm$^2$) are required, OLP uses a hardcoded list of aperture versus focal plane area (parameter $A(a)$ in Section 5.2.5 and in Section 7.10.3). The values of the areas are listed in Section A.1.2.

14.21.1 Product PPOMEGA: aperture dimensions and solid angles for P1, P2, and P3

Binary FITS table with record length 32. The record fields are:

Field	 Offset	Number Type Description
PPOMFILT 0	1      I*4  Filter (CHW position)
PPOMAPER 4	1      I*4  Aperture (CHW position)
PPOMDASY 8	1      R*4  Aperture diameter in Y in arcsec
PPOMDAYU 12	1      R*4  Uncertainty in aperture diameter in Y in arcsec
PPOMDASZ 16	1      R*4  Aperture diameter in Z in arcsec
PPOMDAZU 20	1      R*4  Uncertainty in aperture diameter in Z in arcsec
PPOMOMEG 24	1      R*4  Effective Omega (in $10^{-7}$sr)
PPOMOMUN 28	1      R*4  Uncertainty in Omega (in $10^{-7}$sr)

14.21.2 Product PC1OMEGA: dimensions and solid angles for C100 pixels

Binary FITS table with record length 48. The record fields are:

Field	 Offset	Number Type Description
PC1OMFIL 0	1      I*4  Filter (CHW position)
PC1OMPIX 4	1      I*4  Pixel in SPD order
PC1OMOFY 8	1      R*4  Offset in y relative to centre of array in arcsec
PC1OMOYU 12	1      R*4  Uncertainty in offset in y in arcsec
PC1OMOFZ 16	1      R*4  Offset in z relative to centre of array in arcsec
PC1OMOZU 20	1      R*4  Uncertainty in offset in Z in arcsec
PC1OMDAY 24	1      R*4  Aperture dimension y in arcsec
PC1OMDYU 28	1      R*4  Uncertainty in aperture dimension y in arcsec
PC1OMDAZ 32	1      R*4  Aperture dimension z in arcsec
PC1OMDZU 36	1      R*4  Uncertainty in aperture dimension z in arcsec
PC1OMOME 40	1      R*4  Effective Omega (in $10^{-7}$sr)
PC1OMOMU 44	1      R*4  Uncertainty in omega (in $10^{-7}$sr)

14.21.3 Product PC2OMEGA: dimensions and solid angles for C200 pixels

Same file and record structure as PC1OMEGA (Section 14.21.2), however all keywords start with `PC2' instead of PC1.