Communication and Meteorological Satellite System
INSAT
System
Established in 1983, the Indian National Satellite (INSAT) is the largest
domestic communication satellite systems in the Asia Pacific Region with
nine satellites in operation – INSAT-2E, INSAT-3A, INSAT-3B, INSAT-3C,
INSAT-3E, KALPANA-1, GSAT-2, EDUSAT and INSAT-4A. It is a joint venture
of the Department of Space, Department of Telecommunications, India Meteorological
Department, All India Radio and Doordarshan. The overall coordination
and management of INSAT system rests with the Secretary-level INSAT Coordination
Committee. The latest satellite in the series, INSAT-4B, is getting ready
for its launch from Kourou in French Guyana shortly and will give further
boost to INSAT capability, especially for Direct-To-Home (DTH) television
broadcast.
Satellites
in Service
INSAT-2E: The last of the five satellites in INSAT-2 series, INSAT-2E
is now in its eighth year of service.
It
carries the following payloads:
• Seventeen C-band and lower extended C-band transponders providing
zonal and global coverage with an Effective Isotropic Radiated Power (EIRP)
of 36 dBW.
• A Very High Resolution Radiometer (VHRR) with imaging capacity
in the Visible (0.55-0.75 micron), Thermal Infrared (10.5-12.5 microns)
and Water Vapour (5.7-7.1 microns) channels and providing 2x2 km, 8x8
km and 8x8 km ground resolution respectively.
• A Charge Coupled Device (CCD) camera providing 1x1 km ground resolution
in the Visible (0.63-0.69 micron), Near Infrared (0.77-0.86 micron) and
Shortwave Infrared (1.55-1.70 micron) bands.
Under an agreement with the International Telecommunications Satellite
Organisation (INTELSAT), eleven 36 MHz equivalent units of C-band capacity
on INSAT-2E have been leased to INTELSAT.
INSAT-3
Series
Of the five satellites, INSAT-3A through INSAT-3E, planned under INSAT-3
series, four satellites – INSAT-3A, INSAT-3B, INSAT-3C and INSAT-3E
– have already been launched and are providing satisfactory service.
INSAT-3A
The multipurpose satellite, INSAT-3A, was launched by Ariane in April
2003. It is located at 93.5 degree East longitude. The payloads on INSAT-3A
are as follows:
• 12 Normal C-band transponders (9 channels provide expanded coverage
from Middle East to South East Asia with an EIRP of 38 dBW, 3 channels
provide India coverage with an EIRP of 36 dBW and 6 Extended C-band transponders
provide India coverage with an EIRP of 36 dBW).
• 6 Ku-band transponders provide India coverage with EIRP of 48 dBW.
• A Very High Resolution Radiometer (VHRR) with imaging capacity
in the Visible (0.55-0.75 microns), Thermal Infrared (10.5-12.5 microns)
and Water Vapour (5.7-7.1 microns) channels, provide 2x2 km, 8x8 km and
8x8 km ground resolutions respectively.
• A CCD camera provides 1x1 km ground resolution, in the Visible
(0.63-0.69 micron), Near Infrared (0.77-0.86 micron) and Shortwave Infrared
(1.55-1.70 micron) bands.
• A Data Relay Transponder (DRT) having global receive coverage with
a 400 MHz uplink and
4500 MHz downlink for relay of meteorological, hydrological and oceanographic
data from unattended land and ocean-based automatic data collection-cum-transmission
platforms.
• A Satellite Aided Search and Rescue (SAS&R) payload having
global receive coverage with
406 MHz uplink and 4500 MHz downlink with India coverage, for relay of
signals from distress beacons in sea, air or land.
INSAT-3B
Launched in March 2000, INSAT-3B is collocated with INSAT-2E at 83 degree
East longitude. It carries 12 Extended C-band transponders and three Ku-band
transponders that have coverage over the Indian region. INSAT-3B also
incorporates a Mobile Satellite Services (MSS) payload with forward link
between the hub and mobile station operating in CxS band and return link
between the mobile station and the hub operating in SxC band.
INSAT-3C
Launched in January 2002, INSAT-3C is positioned at 74 degree East longitude.
INSAT-3C payloads include 24 Normal C-band transponders providing an EIRP
of 37 dBW, six Extended C-band transponders with EIRP of 37 dBW, two S-band
transponders to provide BSS services with 42 dBW EIRP and an MSS payload
similar to that on INSAT-3B. All the transponders provide coverage over
India.
KALPANA-1
KALPANA-1 is an exclusive meteorological satellite launched by PSLV in
September 2002. It carries VHRR and DRT payloads to provide meteorological
services. It is located at 74 degree East longitude.
INSAT-3E
Launched in September 2003, INSAT-3E is positioned at 55 degree East longitude
and carries 24 Normal C-band transponders provide an edge of coverage
EIRP of 37 dBW over India and 12 Extended C-band transponders provide
an edge of coverage EIRP of 38 dBW over India.
GSAT-2
Launched by GSLV in May 2003, GSAT-2 is located at 48 degree East longitude
and carries four Normal C-band transponders to provide 36 dBW EIRP with
India coverage, two Ku-band transponders with 42 dBW EIRP over India and
an MSS payload similar to those on INSAT-3B and INSAT-3C.
EDUSAT
Configured for audio-visual medium employing digital interactive classroom
lessons and multimedia content, EDUSAT was launched by GSLV in September
2004. Its transponders and their ground coverage are specially configured
to cater to the educational requirements. The satellite carries a Ku-band
transponder covering the Indian mainland region with 50 dBW EIRP, five
Ku-band spot beam transponders for South, West, Central, North and North
East regional coverage with 55 dBW EIRP and six Extended C-band transponders
with India coverage with 37 dBW EIRP.
EDUSAT is positioned at 74 degree East longitude and is collocated with KALPANA-1 and INSAT-3C.
INSAT-4A
Launched in December 2005 by the European Ariane launch vehicle, INSAT-4A
is positioned at 83 degree East longitude along with INSAT-2E and INSAT-3B.
It carries 12 Ku-band 36 MHz bandwidth transponders employing 140 W TWTAs
to provide an EIRP of 52 dBW at the edge of coverage polygon with footprint
covering Indian main land and 12 C-band 36 MHz bandwidth transponders
provide an EIRP of 39 dBW at the edge of coverage with expanded radiation
patterns encompassing Indian geographical boundary, area beyond India
in southeast and northwest regions.
HAMSAT
Launched on board PSLV-C6 as a co-passenger of CARTOSAT-1 in May 2005,
HAMSAT is an application-specific micro-satellite designed to provide
satellite based Radio Amateur Services to Indian as well as international
HAM (Amateur Radio Operators) community. The 43.5 kg HAMSAT carries Linear
Mode-B (UHF/VHF) transponders – one Indian and the other designed
by a Dutch Amateur Radio Operator from Higher Technical Institute, Venlo,
The Netherlands.
Forthcoming
Satellites
INSAT-4B
Configured with payloads identical to that of INSAT-4A, INSAT-4B will
carry 12 Ku-band and 12 C-band transponders to provide EIRP of 52 dBW
and 39 dBW respectively. Two Tx/Rx dual grid offset fed shaped beam reflectors
of 2.2 m diameter for Ku-band and 2 m diameter for C-band are used. INSAT-4B
is intended to augment the high power transponder capacity over India
in Ku-band and over a wider region in C-band.
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INSAT-4B in its final stages of assembly
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INSAT-4B is planned for launch on board the European ARIANE-5 launch vehicle
in the first quarter of 2007. It will be co-located with INSAT-3A at 93.5
degree E longitude.
During the year, integration of payload and main frame systems have been
completed. Integrated spacecraft tests have also been completed. New electronics
scheme has been configured. The spacecraft has undergone dynamic and radiation
tests and has been transported to Kourou in French Guyana for its launch.
INSAT-4CR
Fabrication of INSAT-4CR was taken up during the year as a replacement
for INSAT-4C, the launch of which was unsuccessful in July 2006. INSAT-4CR
will be identical to INSAT-4C with 10/12 Ku-band transponders with an
EIRP of 51.5 dBW. It will
be positioned at 74 degree E longitude co-located with INSAT-3C, KALPANA-1
and GSAT-3.
During the year, all layouts have been finalised and subsystems are under
fabrication. All electronics packages are under wiring and testing. Spacecraft
structure is in the final stages of integration. Solar panel substrates
have also been realised and solar cell bonding is in progress. Payload
system elements are under realisation.
GSAT-4
GSAT-4 is envisaged as a technology demonstrator. Its communication payload
consists of multi-beam Ka-band bent pipe and regenerative transponder and navigation payload
in C, L1 and L5 bands.
GSAT-4 will also carry a scientific payload, TAUVEX, comprising three Ultra-Violet band telescopes developed by Tel Aviv University and Israel space agency (ELOP) for surveying a large part of the sky in the 1400-3200 A wavelengths.
GSAT-4 employs several new technologies like electric propulsion with four stationary plasma thrusters, Bus Management Unit (BMU), miniaturized dynamically tuned gyros, 36 AH Lithium ion battery, 70 V bus for Ka-band TWTAs, on-board structural dynamic experiment, thermal control coating experiment and vibration beam accelerometer. GSAT-4 is planned for launch by GSLV during 2007-08.
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Ka-band Segmented Multi-beam Antenna and Feed Systems for GSAT-4 |
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During the year, north and south equipment panel have been realised and TAUVEX engineering and structural model interface validation tests completed. Preliminary design review of Ka-band shaped segmented multi beam antenna, electrical and mechanical systems have been completed.
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Antenna tests of INSAT-4B in the Compact Antenna Test Facility at ISITE |
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| INSAT-3D Meteorological Sounder under integration and test |
GSAT-5/INSAT-4D
Configured as an exclusive C-band communication satellite, GSAT-5/INSAT-4D
will carry
12 normal C-band transponders and six extended C-band transponders with wider coverage
in uplink and downlink coverage over Asia, Africa and Eastern Europe as
well as zonal coverage with minimum of 35 dBW EIRP. It will be launched on board GSLV during 2008-09 and positioned at 82 deg E longitude.
During the year, GSAT-5/INSAT-4D payload configuration has been finalised. Spacecraft antenna configuration has been finalised to include two deployable shaped reflectors and one single shell shaped reflector.
GSAT-6/INSAT-4E
GSAT-6/INSAT-4E will carry digital multimedia broadcasting payload. The
satellite will cover entire India through five S-band spot beams using
SxC and CxS transponders. The C-band coverage for the feeder link will
have India coverage. The satellite is planned to be launched during 2009-10
by GSLV.
GSAT-7/INSAT-4F
GSAT-7/INSAT-4F is proposed as a multi-band satellite carrying payloads in UHF, S-band, C-band and Ku-band. It is
planned to be launched during 2010-11 by GSLV.
GSAT-8/INSAT-4G
GSAT-8/INSAT-4G is proposed as a Ku-band satellite carrying 18 transponders
similar to
that of INSAT-4A and INSAT-4B. It will also carry 2 BSS transponders
and a GPS Aided
Geo Augmented Navigation (GAGAN) payload. The satellite
is expected to be launched during 2009-10.
INSAT-3D
INSAT-3D is a meteorological satellite planned to be launched in the 2008-09.
The satellite has many new technology elements like star sensor, micro
stepping Solar Array Drive Assembly (SADA) to reduce the spacecraft disturbances
and Bus Management Unit (BMU) for control and telecomm and/telemetry function.
It also incorporates new features of bi-annual rotation and Image and
Mirror motion compensations for improved performance of the metrological
payloads.
W2M
W2M is being developed and built for EUTELSAT, jointly with EADS-Astrium
under a contract through ANTRIX. EADS Astrium is the prime contractor
in charge of overall programme management and will build the communications
payload. ANTRIX/ISRO will build the satellite bus, based on the flight
proven I-3K model, integrate and test the spacecraft. ISRO will also be
in charge of early in-orbit operations.
W2M will operate typically 26 transponders in Ku-band and up to 32 depending on operational modes, for a designed operational lifetime of 15 years. W2M displays great flexibility to operate a wide range of services from television broadcasting to data networks and broadband. It will have a fixed beam coverage for Europe, North Africa and Middle East and a steerable beam which can be re-oriented in orbit according to market requirements, notably towards Africa and central Asia.
W2M is to be delivered to Eutelsat for launch in the second quarter of
2008.
During the year the tasks completed include: equipment qualification status
review, material and process control board review for the declared materials
list, finalisation of reflector configurations and interfaces, preparation
of interface reference drawings, baseline design review and finalisation
and release of solar array mechanisms components for fabrication.
Satellite Navigation
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| IRNSS concept |
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| Location of IRNSS satellites |
The Government has approved the Indian Regional Navigation Satellite System
(IRNSS).
It consists of a constellation of seven satellites – three
in Geo Stationary Orbit (GSO) and four in Near-GSO. Indian Regional Navigation
Satellite System (IRNSS) management structure for system implementation
has been established and detailed system definition (space segment and
ground segment) work has begun. IRNSS is expected to provide
position
accuracies comparable to the declared position accuracies by other global
constellations in a region centred over India and extending to adjoining
areas. It is expected to implement this regional navigation system in
about 5 to 6 years. IRNSS satellites will transmit ranging codes and navigation
data in S and L-5 bands. The Navigation software and user receiver specifications
are being finalized.
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| C-band upconverter and Surface Acoustic Wave (SAW) Filter for GAGAN |
The Technology Demonstration System (TDS) phase of the Indian Satellite-Based Augmentation System GAGAN is coming to a close. Eight Indian Reference Stations, one Master Control Centre (MCC) and one Indian Land Uplink Station have been commissioned. The Preliminary System Acceptance Test was successfully carried out in May 2006. TheFinal System Acceptance Test is scheduled to be completed in early 2007.
The first navigation payload flight model is almost ready and it is proposed to be flown on GSAT-4 expected to be launched in 2007. Two more payloads will be subsequently flown on GSAT-8 and GSAT-9.
ANUSAT
ANUSAT, a 35 kg micro-satellite, is being designed by Anna University,
Chennai. The main objective is to involve universities in building micro
satellites as a means to promote and encourage intra-disciplinary technologies
with the help of ISRO.
ANUSAT carries a digital store and forward payload for amateur communication. In addition, a number of technological payloads like digital receiver and turbo coder, MEMS-based gyro and magnetic field sensor are planned to be flown on board. Structure, solar panels, chemical battery, sensors and actuators will be supplied by ISRO. The payloads and the other satellite subsystems are designed and fabricated at Anna University.
The configuration of this satellite has been finalised and preliminary design review completed. Breadboard design of core electronic systems has also been completed. The flight model is expected to be realised during 2007-08.
Advanced Technology Development
Development of stratospheric platforms for broadband communication applications
are being studied involving the use of airship. Other developments in
satellite technology include smart structures, large unfurlable antenna
for GSAT-6 spacecraft, robatics, etc, have continued during the year.
Master Control Facility (MCF)
MCF continue to provide in orbit operation of geostationary satellites
during the year. It is
now controlling nine on orbit satellites – INSAT-2E, INSAT-3B, INSAT-3C,
INSAT-3A, INSAT-3E, INSAT-4A, KALPANA-1, GSAT-2 and EDUSAT. Seven of these
satellites are controlled from MCF, Hassan and two (EDUSAT and INSAT-3B)
from MCF Bhopal. MCF, Hassan has an integrated facility consisting of
seven satellite control earth stations. MCF, Bhopal, is configured with
11 m diameter full motion antenna and three 7.2 m diameter limited motion
antenna. During the year one limited motion antenna terminal operating
in C-band was added to MCF, Bhopal.
