MIPAS Pointing assessment
(1) IMK Karlsruhe, Forschungszentrum Karlsruhe, 76344 Eggenstein-Leopoldshafen, Germany
M. Kiefer, T. von Clarmann, B. Funke*, N. Glatthor, U. Grabowski,
M. Hoepfner, S. Kellmann, A. Linden, M. Lopez-Puertas*, M. Milz,
T. Steck, G.P. Stiller, D.-Y. Wang, and H. Fischer
Forschungszentrum Karlsruhe, Institut fuer Meteorologie und
Klimaforschung (IMK), Karlsruhe, Germany
*Instituto de Astrofisica de Andalucia, CSIC, Granada, Spain
The scientific L2 retrieval processor for MIPAS operated at IMK
allows to retrieve pointing information, in terms of tangent altitudes,
along with temperature. The retrieved tangent altitudes are independent
of engineering line-of-sight information.
The difference of pointing retrieved from the reprocessed high
resolution MIPAS spectra and the engineering pointing information
was examined wrt spatial/temporal behaviour.
Among others the following characteristics of MIPAS pointing could be
Prior to December of 2003 there is a drift of about 50-100 m/h, which is
due to a slow change in the satellite attitude.
A correction of this attitude is done twice a day, which leads to
discontinuities in the order of up to 2 km in the pointing.
Further there is a systematic difference of mispointing between the
poles which amounts to 1.5-2 km, i.e. there is a conspicuous orbit-periodic
The analysis of the correlation between the instrument's viewing angle
azimuth and differential mispointing supports the hypotheses that part
of this latter phenomenon can be attributed to an uncorrected roll angle
of the satellite/instrument system of approx. 30-50 mdeg.
Keywords: ESA European
Space Agency - Agence spatiale europeenne,
observation de la terre, earth observation,
satellite remote sensing,
teledetection, geophysique, altimetrie, radar,
chimique atmospherique, geophysics, altimetry, radar,