Indian National Satellite System
The Indian National Satellite System or INSAT, is a series of multipurpose geostationary satellites launched by the Indian Space Research Organisation (ISRO) to satisfy telecommunications, broadcasting, meteorology, and search and rescue operations.
The satellites also incorporate transponder(s) for receiving distress alert signals for search and rescue missions in the South Asian and Indian Ocean Region, as ISRO is a member of the Cospas-Sarsat program.
INSAT system ushered in a revolution in India's television and radio broadcasting, telecommunications and meteorological sectors.
It enabled the rapid expansion of TV and modern telecommunication facilities to even the remote areas and off-shore islands.
All the transponders provide coverage over large part of the Indian Ocean region covering India, Bangladesh, Bhutan, Maldives, Nepal, Seychelles, Sri Lanka and Tanzania for rendering distress alert services.
[5] INSAT-3DR is a weather satellite meant to provide meteorological services to India using a 6-channel imager and a 19-channel sounder, it was launched on 9 September 2016 by the GSLV Mk II F05,[6] and is a follow-up to INSAT-3D.
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.
INSAT-A 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.
INSAT-4B augments the high power transponder capacity over India in Ku band and over a wider region in C-band.
[10] The national space agency Indian Space Research Organisation (ISRO) has allotted nearly seven Ku band transponders to Sun Direct; a DTH service provider from South India, and the other five to Doordarshan's DD Direct Plus.
He also pointed out that Stuxnet was discovered just a month before the Indian satellite was hit by the power glitch, the reason for which still remains unknown.
It carries 12 Ku band 36 MHz bandwidth transponders employing 140 W TWTAs to provide an Effective Isotropic Radiated Power of 51.5 dBW at Edge of Coverage with footprint covering Indian mainland.
Launched by the second flight of 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.
Configured for audio-visual medium employing digital interactive classroom lessons and multimedia content, GSAT-3 (EDUSAT) was launched by a GSLV in September 2004.
It serves with C and Ku band transponders, and includes a navigation payload to augment GAGAN capacity.
The 12 Extended C-band transponders of GSAT-12 will augment the capacity in the INSAT system for various communication services like Tele-education, Telemedicine and for Village Resource Centres (VRC).
GSAT-15 is similar to GSAT-10 and is used to augment the capacity of transponders to provide more bandwidth for Direct-to-Home television and VSAT services.
It additionally carries a dedicated transponder for data relay (DRT) and search-and-rescue (SAR) services.
Launched on 5 June 2017, GSAT-19 is a communication satellite testbed for the modular I-6K satellite bus, carrying experimental technologies such as ion thrusters for manoeuvring and stabilisation, active thermal control using thermal radiators, a miniaturised inertial reference unit, indigenously produced lithium-ion batteries, and C-band traveling-wave-tube amplifiers.
