Centre d'Etudes Spatiales des Rayonnements, BP 4346, F-31028 Toulouse cedex 4, France
The LWS Parallel Observing Mode (in use when another instrument than LWS is
prime during routine pointed observations), and the LWS Serendipity
Observing Mode (in use when the satellite is slewing from one source to
another), allow to probe the Interstellar Medium, particularly along the
galactic ridge.
We present here some preliminary results of these observing modes and the
calibration and data processing procedures.
In these observing modes, all LWS mechanisms are frozen, and using part of
the housekeeping telemetry, we transmit to the ground one information per
detector and per second. This allows to obtain every second, during the
whole orbit, a spectrum of the position aimed by ISO in ten narrow
wavebands (
), between 46
m and
178m.
The Parallel Observing Mode is optimum when the prime instrument is
performing a raster observation, allowing LWS to map the sky emission in
its ten narrow wavebands.
In the Serendipity Observing Mode, the satellite velocity is
/minute, leading to a virtual field of view of about
70" x 490". The numerous slews of ISO during his life will allow to build a
catalog of cold far infrared sources.