摘要：In this paper, the possibilities of satellite-based and
ground-based stereoscopy of clouds are examined,
with the objective to derive cloud top and cloud base
heights and motion. These parameters are very important for a better description of clouds for nowcasting
and numerical weather prediction models. For the satellite part, images of ATSR2 (on ERS-2) and MISR
(on EOS Terra) are used. As stereo image pairs from
polar-orbiting satellites are never perfectly synchronous
(time delay of some seconds between the image
reeeption from the different viewing angles), the height
error of the cloud top heights, introduced by the
along-track motion component, is corrected with the
cloud top winds extracted from Meteosat-6 and -7.
For MISR, with nine viewing angles, this height correction is not needed when at least three images from
non-symmetric cameras are used; then, it is possible
to directly separate the along-track parallax (due to
cloud height) from the along-track wind contribution
(due to cloud motion). Our new ground-based imager
System was operated in eoineidence with an overpass
of ERS-2 in October 1999. The ground measurements
proved to be an interesting technique to validate satellite-based cloud top height and motion of vertically
thin clouds and to additionally detect more detailed
cloud features, which is particularly important for aecurate
noweasting in mountainous terrain.
