legendry Ahmedabad Earth Station built in 1966
Centre (SAC), is a major research and development centre of the
Indian Space Research Organisation (ISRO). It plays a key role in
realizing vision and mission of ISRO. Located at Ahmedabad, SAC is
spread across two campuses having multi-disciplinary activities.
The core competence of the centre lies in development of
space borne and air borne instruments/payloads and their
applications for national development and societal benefits. These
applications are in diverse areas and primarily meet the
communication, navigation and remote sensing needs of the country.
Besides these, the centre also contributes significantly in
scientific and planetary missions of ISRO like Chandrayan-1, Mars
Orbiter Mission etc.
transponders developed at this centre for Indian National
Satellite (INSAT) and Geo Synchronous Satellite (GSAT) series of
satellites are used by government and private sector for VSAT,
DTH, internet, broadcasting, telephony etc. These satellites are
instrumental in reaching remote parts of the country. The payloads
for major navigation systems of the country - Indian Regional
Navigation Satellite System (IRNSS) and GPS Aided Geo Augmented
Navigation (GAGAN) are being developed by this centre.
This centre designs and develops the optical and microware sensors
for the satellites, signal and image processing software, GIS
software and many applications for Earth Observation (EO)
programme of ISRO. These applications are in diverse areas of
Geosciences, Agriculture, Environment and Climate Change, Physical
Oceanography, Biological Oceanography, Atmosphere, Cryosphere,
The facilities at SAC includes
highly sophisticated payload integration laboratories, electronic
and mechanical fabrication facilities, environmental test
facilities, systems reliability/assurance group, image processing
and analysis facilities, project management support group and a
well-stocked library. SAC has active collaborations with industry,
academia, national and international institutes for research and
development. The centre also has state-of-art in-house and mobile
exhibitions to propagate space technology and applications amongst
students and public.
The Centre also conducts
nine-month post graduate diploma courses for students from the
Asia Pacific region under the aegis of the Centre for Space
Science and Technology Education (CSSTEAP) in satellite
meteorology and communication.
Genesis and History
genesis of the centre dates back to 1966, with establishment of
the Experimental Satellite Communication Earth Station (ESCES), by
late Dr. Vikram Sarabhai in Ahmedabad. It was an experimental
Earth Station and training centre where scientists and engineers
of India and other developing countries could receive training and
firsthand experience in the design, development and operations of
an earth station for communications and broadcasting.
Later in 1972, the different units of ISRO in Ahmedabad
pursuing research in applications of space technology were merged
to form SAC. During 1975-76 a unique experiment called the
Satellite Instructional Television Experiment (SITE) was conducted
by SAC/ISRO utilizing the American ATS-6 satellite. This involved
telecasting educational programmes aimed at socio-economic
development of rural India, which covered 2400 villages - spread
over six states - through experimental Direct Reception Sets. SITE
was followed by communication techniques developmental project
called Satellite Telecommunications Experiments Projects (STEP),
carried out with the Frenco-German satellite, Symphony.
The payload for first experimental communication satellite
of India, ‘APPLE’ was designed, fabricated and qualified at SAC.
It was launched onboard the first experimental flight of the
Arian. An exhaustive communication applications programme called
the APPLE Utilization Programme (AUP) was also conceived and
The INSAT-1 series of satellite was custom designed and
made as per the unique requirements of the country by a US
company. The INSAT 2A, 2B, 2C, 2D and 2E, launched in the years
1992, 1993, 1995, 1997 and 1999 respectively, were designed,
fabricated and qualified / indigenously at SAC.
The present remote sensing programme of ISRO started in
early 1970s. Payload development at SAC was started with balloon
experiments followed by aerial photography for remote sensing. At
the same time activities were also carried in the field of
meteorology with available data from foreign satellites and from
indigenously developed airborne thermal scanner.
The first phase saw the development of airborne thermal
sensors, multispectral scanner, linear Charge Coupled Device (CCD)
camera, Side Looking Radar, Colour Infrared (CIR) based
photographic systems and a number of photo interpretation and
ground truth equipment. Based on above initial work, a strong
applications programme was evolved around these instruments.
Foundations for space borne sensors were laid during this period.
Under the programme ‘Satellite for Earth Observation (SEO)’, two
satellites were launched and called Bhaskara satellites after
their Launch onboard Russian launch Vehicle. Bhaskara carried a 1
km resolution 2 बैंड TV camera systems and a three channel
microwave radiometer. These were designed, developed and
successfully qualified in house. Bhaskara I and II were the first
Indian Meteorological satellites which carried microwave
radiometer called SAMIR to provide information on sea state and
atmospheric water vapour content for use in meteorological
The second phase in 1980s witnessed the results of earlier
efforts of experimental satellites. The IRS 1A programme was
successfully launched and the users started receiving
multispectral imagery with 36m resolution. Major applications in
agriculture, hydrology, geology and other areas were defined in
close interaction with user agencies and the IRS utilization
programme was carried out successfully. These efforts led to
semi-operational applications of IRS 1A data.
Strong foundation was also laid for airborne SAR system
development, its data processing and applications at SAC. The
advanced activities carried out at at the centre during the third
phase in 1990s put India at par with many other advanced nations
through the design of high resolution sensors in the optical and
microwave regions including a successfully flown airborne SAR
system and a very sophisticated application programme tuned to our
country's needs. The 5.8 m resolution Pan Camera of IRC 1C & 1D
revolutionized the applications concept in the country. Being the
best resolution civilian sensor in the world at that time, it
attracted the attention of foreign users.
SAC has state of the art General Circulation Models for
experimentation with satellite data. Prediction of weather in the
extended range and prediction of Ocean state in the short range
are the fields of active research.