Communication and Meteorological Satellite System


 

INSAT System

The Indian National Satellite (INSAT) system is a joint venture of the Department of Space (DOS), Department of Telecommunications (DOT), India Meteorological Department (IMD), All India Radio (AIR) and Doordarshan. The overall coordination and management of INSAT system rests with the Secretary-level INSAT Coordination Committee (ICC). Established in 1983, INSAT has become one of the largest domestic communication satellite systems in the Asia Pacific Region with eight satellites in operation — INSAT-2E, INSAT-3A, INSAT-3B, INSAT-3C, INSAT-3E, KALPANA-1, GSAT-2 and EDUSAT.

Satellites in Service

EDUSAT

The launch of EDUSAT, India's first thematic satellite for addressing the educational services on September 20, 2004, was an important landmark during the year. The satellite is specially configured for audio-visual medium, employing digital interactive classroom and multimedia, multi-centric system. The satellite transponders and their ground coverage are specially configured to cater to the educational requirement of the country.


EDUSAT under final stages of assembly and testing

EDUSAT carries:

  • One Ku-band national beam transponder covering the Indian mainland region, with 50 dBW Effective Isotropic Radiated Power (EIRP).
  • Five Ku-band spot beam transponders - South, West, Central, North East, and North with 55 dBW EIRP.
  • Six Extended C-band transponders with Indian coverage with 37 dBW EIRP.

After its injection into Geostationary Transfer Orbit by GSLV, EDUSAT was successfully manoeuvred to its allocated orbital slot of 74 degree East longitude where it is collocated with Kalpana-1 and INSAT-3C. The communication transponders of EDUSAT have been tested and the satellite is ready for use.

INSAT-2 Series

INSAT-2E, the last of the five satellite in the series, is now in its sixth year of service. It carries the following payloads:

  • Seventeen C-band and lower extended C-band transponders providing zonal and global coverage with an EIRP of 36 dBW.
  • A Very High Resolution Radiometer (VHRR) with imaging capacity in 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 Visible (0.63-0.69 micron), Near Infrared (0.77-0.86 micron) and Shortwave Infrared (1.55-1.70 microns) bands.

Under an agreement with the International Tele-communications 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 on April 10, 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 providing India coverage with an EIRP of 36 dBW).
  • 6 Ku-band transponders providing India coverage with EIRP of 48 dBW.
  • A Very High Resolution Radiometer (VHRR) with imaging capacity in Visible (0.55-0.75 microns), Thermal Infrared (10.5-12.5 microns) and Water Vapour (5.7-7.1 microns) channels, providing 2x2 km, 8x8 km and 8x8 km ground resolutions 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.
  • 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

INSAT-3B was launched on March 23, 2000. It is collocated with INSAT-2E at 83 degree East longitude. INSAT-3B comprises the following payloads covering Indian region:

  • 12 Extended C-band transponders.
  • 3 Ku-band transponders.
  • A Mobile Satellite Services (MSS) payload with forward link between the hub and mobile station operates in CXS band and return link between the mobile station and the hub operates in SXC band.


INSAT-3C

INSAT-3C was launched on January 24, 2002. It is positioned at 74 degree East longitude. Following are the INSAT-3C payloads with India coverage:

  • 24 Normal C-band transponders providing an EIRP of 37 dBW.
  • 6 Extended C-band transponders with EIRP of 37 dBW.
  • 2 S-band transponders to provide BSS services with 42 dBW EIRP.
  • A Mobile Satellite Services (MSS) payload similar to INSAT-3B.


KALPANA-1

KALPANA-1 is an exclusive meteorological satellite which was launched by PSLV on September 12, 2002. The satellite comprise a VHRR and a DRT payload to provide meteorological services. It is located at 74 degree East longitude.

INSAT-3E

INSAT-3E was launched on September 28, 2003. It is positioned at 55 degree East longitude. The payloads of INSAT-3E comprise the following:

  • 24 Normal C-band transponders providing an edge of coverage EIRP of 37 dBW over India.
  • 12 Extended C-band transponders providing an EIRP of 38 dBW over India.

GSAT-2

GSAT-2 was launched on May 8, 2003 by GSLV from SDSC SHAR. It is located at 48 degree East and carries the following payloads:

  • 4 Normal C-band transponders to provide 36 dBW EIRP with India coverage.
  • 2 Ku-band transponders with 42 dBW EIRP over India.
  • A Mobile Satellite Services (MSS) payload similar to INSAT-3B and INSAT-3C.


Forthcoming Satellites

INSAT-3D

INSAT-3D carries the state-of-the-art meteorological payloads namely 6 channel imager and 19 channel sounder. During the year, configuration of the spacecraft has been finalised and design of all subsystems completed. The launch is planned during 2007-08.

INSAT-4 Series

INSAT-4 series is planned to have seven satellites. The transponder configuration of the series has been worked out after evaluating the requirement projected by different users/user departments. INSAT will have about 225 active transponders in various frequency bands by 2007, which can cater to the demand up to 11 GBPS capacity with present day technology. The transponders on INSAT-4 series are distributed as follows:




INSAT-4A spacecraft structure undergoing test

INSAT-4A

INSAT-4A the first in the INSAT-4 series will carry 12 Ku-band and 12 C-band transponders. The Ku-band transponders will primarily meet the growing demand of DTH. The launch of INSAT-4A is planned in the first half of 2005. During the year all the subsystems for the satellite have been realised and the spacecraft integration completed.

INSAT-4B

INSAT-4B will also carry 12 Ku-band and 12 C-band transponders. The Ku-band transponders on INSAT-4B will meet the additional demand. It is planned for launch during 2005-06. The realisation of the subsystems have progressed well during the year and the payloads are expected to be ready by the first quarter of 2005. The satellite integration is planned by the middle of 2005.

INSAT-4C

INSAT-4C is an exclusive Ku-band satellite with 12 transponders. During the year, the configuration of the spacecraft including the communication payload and antenna systems, has been finalised. The launch interface has also been defined.

GSAT-4

GSAT-4 is primarily an experimental satellite for Ka band communication payload. The payload composition is as follows:

  • Eight transponders for Ka-band regenerative and bend-pipe payload. Regenerative payload can cater to countrywide demand of hubless VSAT connectivity.
  • Navigation payload as part of GAGAN project using CXL and CXC links to augment GPS system to Category-1 type navigation.
  • Tel Aviv University Ultra Violet Experiment (TAUVEX) consisting of three UV imagers for surveying the sky in the wavelengths of 1400 to 3200 Ao .

During the year, spacecraft level design review has been completed. The interface for the TAUVEX payload has been reviewed. The layout of the equipment on the north, south and earth viewing panels has been finalised. The launch of GSAT-4 is planned during 2006-07.

GSAT-5/INSAT-4D

The government has approved the GSAT-5 project during the year. It is an exclusive C-band satellite carrying 24 transponders. Of these, 12 transponders have India coverage and other 12 have expanded coverage. The satellite is slated for launch on board GSLV during 2006-07.

HAMSAT

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, planned for launch on board PSLV-C6 as a co-passenger of CARTOSAT-I, will carry Linear Mode B (UHF/VHF) transponders — one Indian transponder and the other designed by a Dutch Amateur Radio Operator from Higher Technical Institute, Venlo, The Netherlands.

During the year, the transponder chain has been integrated and spacecraft level thermovac test completed.

ANUSAT

ANUSAT is a 50 kg micro satellite being designed and fabricated at Anna University, Chennai. The aim is to bring university based academicians and research and development experts of ISRO together to implement a project in university environment. ANUSAT carries a digital store and forward payload for amateur communication. In addition, a number of technological payloads like digital receiver and turbo coder and MEMS based gyro and magnetic field sensor are planned to be in this micro satellite. During the year, the configuration of this satellite has been finalised and breadboard/design verification models of the core electronic systems completed.

Master Control Facility (MCF)

During the year, MCF successfully carried out the launch and early orbit phase operations of EDUSAT.

The Satellite Control Centre at MCF is interfaced with all the Satellite Control Earth Stations thus providing flexibility in operations. The new network switches added to the MCF mission computer network last year is being extensively used for archival of telemetry data from all the satellites.

MCF-Bhopal

MCF- Bhopal is configured with one 11 meter diameter full motion antenna and three 7.2 meter diameter limited motion antennas, a satellite control centre and a power complex. Civil construction of the technical facilities has progressed well and is nearing completion. Installation of equipment is in progress.