Next: 13.19 Colour corrections Up: 13 Calibration G Products Previous: 13.17 Conversion from power

13.18 Effective solid angles of apertures and pixels


Description Parameter:	 sections 4.5.1 and 5.3
Processing Level:	 AAR
Usage in processing:	 section 8.4.10
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 to OLP Version 7 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.

13.18.1 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
PPOMDAEG	24		1		R*4		Effective Omega (in 10^-7sr)
PPOMDAUN	28		1		R*4		Uncertainty in Omega (in 10^-7sr)

13.18.2 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
PC1OMDAY	32		1		R*4		Aperture dimension z in arcsec
PC1OMDYU	36		1		R*4		Uncertainty in aperture dimension z in arcsec
PC1OMOME	40		1		R*4		Effective Omega (in 10^-7sr)
PC1OMOMU	44		1		R*4		Uncertainty in omega (in 10^-7sr)

13.18.3 Product PC2OMEGA: dimensions and solid angles for C200 pixels

Same file and record structure as PC1OMEGA (section 13.18.2), however all keywords start with ``PC2'' instead of PC1.

Next: 13.19 Colour corrections Up: 13 Calibration G Products Previous: 13.17 Conversion from power

ISOPHOT Data Users Manual, Version 4.1, SAI/95-220/Dc