Page 91 - Digital Analysis of Remotely Sensed Imagery

62 Cha pte r T w o

dynamic range of 10 bits preprocessed to three levels: 1A (radiometric
correction), 2A (radiometric and geometric correction), and ortho
(SPOT Image, 2004). Similar to Formosat, Kompsat data may be
purchased from SPOT Image at 10 euro/km for either panchromatic
2
or multispectral bands at the 1A or 2A levels. A minimum order
2
of 225 km is imposed for level 1A data. This size drops to 100 km 2
for level 2A data. Price is higher for data acquired via special
programming.
COSMO-SkyMed is an Earth observation remote sensing system
designed for both military and civilian applications. Consisting of
four satellites, the first COSMO-SkyMed was launched on June 7,
2007, followed by COSMO-2 on December 9, 2007. COSMO-3 will be
launched in 2008. All satellites share the same orbital plane, though
not the same bands (i.e., C, L, and P bands are used, respectively).
Unlike other very high spatial resolution imagery, COSMO-1 imagery
is microwave SAR at 9.6 GHz (X band). The area of interest can be
sensed several times a day. There are two constellation configurations:
stand alone or interferometric. In the second configuration, a pair of
3D SAR imagery is created by joining two radar images that are
recorded at slightly different incident angles (Wade, 2007). Image
resolution varies from 1 m in the Spotlight/frame mode to 3 to 15 m
in the Himage mode in which strip images covering a swath width of
40 km are acquired. It degrades further to 30 m and 100 m in the
WideRegion mode and the HugeRegion mode, respectively. Swath
width doubles from 100 km to 200 km as the mode switches from the
WideRegion to HugeRegion. Major civilian applications of COSMO
data include seismic hazard analysis, monitoring of environmental
disasters such as landslides and floods, monitoring of coastline and
sea waters, and agricultural mapping (e.g., harvest planning and
management of treatment cycles).
Unlike the above satellites, Pleiades-1 is still at the planning
stage, scheduled for launch into a sun-synchronous orbit at a height
of 695 km in 2009. It is intended as a follow up of the SPOT satellite
program with improved resolution over a field 20 km wide. Similar
to SPOT, it also retains the stereoscopic viewing capability. It records
one panchromatic band of 0.7 m resolution and four multispectral
bands of 2.8 m resolution, identical to those of Kompsat-3, and EROS
C imagery.

2.5 Hyperspectral Data
The third trend in data acquisition that emerged about a decade ago is
termed hyperspectral remote sensing because it involves sensing the
target in hundreds of spectral bands simultaneously, in sharp contrast
to tens of spectral bands that have been the norm of multispectral
remote sensing. These hyperspectral bands cover roughly the same
wavelength range as that of multispectral bands. Hence, each