IEEE Geoscience and Remote Sensing Magazine - December 2014 - 47

Bhaskara-I RS D-1 Bhaskara-II RS D-2
1979
1981
1981
1983

1980

IRS-1B
1991

INSAT-2A INSAT-2B
1992
1993

INSAT-1B
1983

IRS-P2
1994

1990

IRS-1A
1988

1985
IRS-1C
1995

IRS-P3
1996

IRS-1D
1997

INSAT-1C
1988

INSAT-1E
1999

1995
TES
2001

2000
Cartosat-2B
2010

Kalpana-1 Resourcesat-1
2002
2003

2010

2000

Cartosat-1
2005

2005
ResourceRISAT-1
INSAT-3D
sat-2
2013
2011 Megha 2012 SARAL
2013
Tropiques
2011

1990
Oceansat-1
1999

Cartosat-2 Cartosat-2A IMS-1 RISAT-2
2007
2008
2008
2009 Oceansat-2
2009

2010

ISO's EO Programme at a Glance

2015

Figure 1. Evolution of ISRO's EO Programme.

A. ElEctro opticAl cAmErA BAsEd sEnsors
The first Electro Optic sensor flown on BHASKARA-1
and -2 was based on vacuum tube technology (Vidicon
TV camera), yet ISRO was the first, along with SPOT, to
introduce CCD-based push broom imaging in IRS-1A. It
was a significant departure from the whiskbroom technology in MSS (Multi Spectral Scanner), adopted for the
contemporary Landsat series.
ISRO's first operational satellite, designed for Earth
resource monitoring, was IRS-1A, followed by IRS-1B.
The satellite was configured for a near-circular sun-synchronous polar orbit. The payloads consisted of two cameras: one low resolution four band multispectral camera
named the Linear Imaging Self Scanner (LISS-1) and the
other a medium resolution four band multi spectral scanner (LISS-2).
The push-broom cameras selected for these missions
employed all solid state technology (2048 elements, 13
micron pixel CCD) to provide better SNR and radiometric accuracy. For all 4 bands, separate camera systems with
separate electronics were used, avoiding single point failure. This called for sophisticated band-to-band registration
algorithms in the ground processing software.
december 2014

ieee Geoscience and remote sensing magazine

The experience obtained in using IRS-1A/1B data provided the configuration definition for IRS-1C/1D. A threetier imaging capability was incorporated with the (a) WiFS
(Wide field sensor) camera, providing coarse ground resolution (188 m) data with wide swath (700 km) (b) LISS-3
camera, providing medium resolution data (23.5 m in
VNIR and 70 m in SWIR) with a swath of 140 km and
(c) Panchromatic camera, providing high resolution data
(5.8 m) with a swath of 70 km. The entire electro-optical
module was mounted on a payload steering mechanism
to facilitate faster revisit (+/-26° across track) and also
acquiring across track stereo pairs.
Resourcesat-1 had further improvements over IRS1C/1D with new detectors and technologies. They are: (a)
the 5.8 m panchromatic camera was enhanced to be multispectral (LISS-4) (b) a resolution of 23.5 m was introduced
in the SWIR channels of LISS-3 and (c) WiFS was enhanced
to Advanced WiFS (AWiFS) to finer resolution (70 m) and
to incorporate 4 bands (B2, B3, B4 and SWIR).
Further improvements were made in Resourcesat-2 by
improving contrast in LISS-4 and 100% albedo coverage
in a single gain setting using DPCM for LISS-4 and LISS-3.
Resoursat-2 has 10 bit radiometric resolution as well as
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Table of Contents for the Digital Edition of IEEE Geoscience and Remote Sensing Magazine - December 2014