Bibcode
Klaas, U.; Ábrahám, P.; Acosta-Pulido, J. A.; Héraudeau, P.; Kiss, C.; Laureijs, R. J.; Lemke, D.; Richards, P. J.; Schulz, B.; Stickel, M.
Referencia bibliográfica
`The calibration legacy of the ISO Mission', proceedings of a conference held Feb 5-9, 2001. Edited by L. Metcalfe, A. Salama, S.B. Peschke and M.F. Kessler. Published as ESA Publications Series, ESA SP-481. European Space Agency, 2003, p. 19.
Advertised on:
0
2003
Número de citas
6
Número de citas referidas
6
Descripción
ISOPHOT, the imaging spectro-photo-polarimeter on board ISO, supported
performance of aperture and mapping photometry, low-resolution
spectroscopy and polarimetry, both in staring and chopped mode. In
addition, the 170 μm ISOPHOT Serendipity Survey was performed while
slewing from one target to the next. Its calibration had to be
connected to the pointed and raster observations. One initial aspect
of the calibration program was the finding of optimal observation
strategies (chopping, mini-maps, absolute photometry) depending on
source type. FIR detection limits were determined facing the in-orbit
radiation environment and the inhomogeneous sky background. ISOPHOT's
large wavelength range from 2.5 to 240 μm, covered by 25 filters in
combination with subsets of 17 different apertures or array/pixel sizes,
combined with a large dynamic range set the frame of requirements on
calibration measurements and standards. Based on the pre-flight
characterisation a list of requirements was worked out as a guide for
the calibration planning. An important item in the absolute photometric
calibration was the reference to celestial standards via a transfer
calibration using the internal reference sources. This became
particularly demanding when one of the internal reference sources
changed its radiation properties in the early routine phase. We give an
overview of standard sources, calibration strategies for each main
observational mode and the accuracies achieved so far. With the end of
the ISO Post Operations Phase the scientific validation status of most
of the ISOPHOT observing modes has been established.