The Indian Remote Sensing Satellites use indigenously developed high resolution cameras for generating data related to
vegetation, landform /geomorphic and geological boundaries. This data from this camera is used for working out maps at
1:12500 scale for national level policy development for town planning, vegetation etc. The LISS-4 Camera was launched
onboard Resourcesat-1 satellite by ISRO in 2003. LISS-4 is a high-resolution multi-spectral camera with three spectral
bands and having a resolution of 5.8m and swath of 23Km from 817 Km altitude. The panchromatic mode provides a
swath of 70Km and 5-day revisit. This paper briefly discusses the configuration of LISS-4 Camera of Resourcesat-1, its
onboard performance and also the changes in the Camera being developed for Resourcesat-2.
LISS-4 camera images the earth in push-broom mode. It is designed around a three mirror un-obscured telescope, three
linear 12-K CCDs and associated electronics for each band. Three spectral bands are realized by splitting the focal plane
in along track direction using an isosceles prism. High-speed Camera Electronics is designed for each detector with 12-
bit digitization and digital double sampling of video. Seven bit data selected from 10 MSBs data by Telecommand is
transmitted. The total dynamic range of the sensor covers up to 100% albedo. The camera structure has heritage of IRS-
1C/D. The optical elements are precisely glued to specially designed flexure mounts. The camera is assembled onto a
rotating deck on spacecraft to facilitate ± 26° steering in Pitch-Yaw plane. The camera is held on spacecraft in a stowed
condition before deployment. The excellent imageries from LISS-4 Camera onboard Resourcesat-1 are routinely used
worldwide. Such second Camera is being developed for Resourcesat-2 launch in 2007 with similar performance. The
Camera electronics is optimized and miniaturized. The size and weight are reduced to one third and the power to half of
the values in Resourcesat-1.
This paper deals with the salient features of LISS-3* Camera of Resourcesat-1, its onboard performance and also the
highlights of Camera being developed for Resourcesat-2. LISS-3* camera is based on linear push-broom technique
and contains four independent refractive optics, detectors and associated electronics for each band. The field of view
is 10° and is covered with a single 6000 element linear detector in each band. The visible bands use Silicon CCDs,
having 10μ x 7μ element size and 10μ pitch. The SWIR band uses 13μ pitch staggered InGaAs linear active detector.
Camera Electronics is custom designed for each detector and adopts simultaneous readout mode. The video signal is
digitized with 7-bit ADC in VNIR bands and the gain selection of 1:3 is incorporated to cover wide range. In case of
SWIR band the video digitized with 12 bits of which 10MSBs are transmitted. Four gains are implemented with bit
sliding. The camera components are mounted in a precisely fabricated and stable structure made out of Invar. The
LISS-3* Camera onboard Resourcesat-1 is providing excellent imageries and the data is routinely used world over
primarily for vegetation monitoring. Similar Camera is being developed for Resourcesat-2 keeping the overall
performance characteristics same but minimizing electronic hardware.
Remote sensors were developed and used extensively world over using aircraft and space platforms. India has
developed and launched many sensors into space to survey natural resources. The AWiFS is one such Camera,
launched onboard Resourcesat-1 satellite by ISRO in 2003. It is a medium resolution camera with 5-day revisit
designed for studies related to forestry, vegetation, soil, snow and disaster warning. The camera provides 56m (nadir)
resolution from 817 km altitude in three visible bands and one SWIR band. This paper deals with configuration
features of AWiFS Camera of Resourcesat-1, its onboard performance and also the highlights of Camera being
developed for Resourcesat-2.
The AWiFS is realized with two identical cameras viz. AWiFS-A and AWiFS-B, which cover the large field of view
of 48°. Each camera consists of independent collecting optics and associated 6000 element detectors and electronics
catering to 4 bands. The visible bands use linear Silicon CCDs, with 10μ × 7μ element while SWIR band uses 13μ
staggered InGaAs linear active pixels. Camera Electronics are custom designed for each detector based on detector
and system requirements. The camera covers the total dynamic range up to 100% albedo with a single gain setting and
12-bit digitization of which 10 MSBs are transmitted. The Camera saturation radiance of each band can also be
selected through telecommand. The Camera provides very high SNR of about 700 near saturation. The camera
components are housed in specially designed Invar structures. The AWiFS Camera onboard Resourcesat-1 is
providing excellent imageries and the data is routinely used world over.
AWiFS for Resourcesat-2 is being developed with overall performance specifications remaining same. The Camera
electronics is miniaturized with reductions in hardware packages, size and weight to one third.