|
CONTENTS
|
Geo-stationary Satellite Services The
Geo-stationary Satellites which are placed in an orbit, about 36,000 km
over the equator are Satellites in Service INSAT-2C: INSAT-2C, which was launched on December 7, 1995 is located at 93.5 degree east longitude. INSAT-2DT: To partly augment the capacity of the INSAT system consequent to the loss of INSAT-2D (in October, 1997), an in-orbit satellite, ARABSAT-1C was procured from ARABSAT Organisation, a regional inter-governmental satellite consortium of Arab States. The satellite, designated as INSAT-2DT, is located at 55 degree east. INSAT-2E: INSAT-2E was launched on April 03, 1999. It is located at 83 degree east longitude. 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 under a commercial agreement. INSAT-3B: INSAT-3B, the first satellite launched in the INSAT-3 series on March 22, 2000 is located along with INSAT-2E at 83 degree east longitude.
Payloads on INSAT-3 Satellites in Service
INSAT-3C:
One of the major accomplishments during the
year was the realisation of
Payloads on Follow-on INSAT-3 Satellites
During
the year, assembly of flight structure of METSAT has been completed. North,
south and earth view decks have been realised. Thermal design has been
completed. VHRR cooler housing has been fabricated. Fabrication of solar
array mechanism is nearing completion. All control simulations have been
completed. Experimental
Satellites - GSAT GSAT-1 All
new spacecraft technology elements that were flown on GSAT-1 have been
evaluated. These include (i) Fast Recovery Star Sensor (FRSS) which provides
enhanced accuracy of measuring satellite orientation and for quick earth-lock
recovery in case of loss of lock, (ii) a new earth sensor using pyro electric
detectors, (iii) an alternate strategy for orbit raising using a combination
of four 22 Newton thrusters (iv) thermal control using heat pipes (v)
new technique of power management through charger arrays for improving
the overall efficiency When GSAT-1 is within the radio visibility of INSAT Master Control Facility (MCF), Hassan, it is being used for conducting several spacecraft operations experiments and configuring the spacecraft for unattended mode of operation. Development and equatorial plane. A minor shortfall of 0.6 percent in the velocity of injection of the satellite resulted in a reduction of orbital apogee of the satellite while the perigee and inclination were close to targeted values. Through a series of orbit manoeuvres, the orbit of GSAT-1 was raised close to near-geo-synchronous orbit with an apogee of 35,665 km, perigee of 33,806 km and inclination of 0.997 degree. It has an 4 orbital period of 23 hr 2 minutes. During the orbit raising operations, consumption of propellant on board the satellite was more than planned resulting in a shortage of about 10 kg to implementation of a special software for the on-board AOCE computer to carry out momentum dumping automatically has been specially developed and implemented on the satellite.
GSAT-2 GSAT-2 to be launched by the second developmental flight, GSLV-D2, will have the following payloads:
GSAT-2 will also carry instruments to conduct experiments like total radiation dose monitor, surface charge potential monitor, coherent radio beacon experiment and solar X-ray spectrometer. During the year, assembly of flight structure and dynamic analysis have been completed. Fabrication of solar array deployment mechanism components, C-band reflector components have been completed. All control simulations have been completed. GSAT-3 and GSAT-4 are under planning. One of these satellites is proposed to carry Ka-band regenerative transponders and a large unfurlable antenna and besides other new technologies. INSAT-4
Series INSAT-4 Satellites
Master
Control Facility (MCF) MCF has Spacecraft Control Centre, Telemetry Tracking and Command Network, and associated support facilities. MCF closely interacts with user agencies for payload operations. MCF is equipped with Satellite Control Earth Stations (SCES) with a variety of antenna’s to suit the mission requirements. It has a computer network with servers and workstations for spacecraft mission operations. A multi-mission spacecraft health monitoring and control software has been implemented on this network.
INSAT Services Telecommunications Under Remote and Rural Area Communications using MCPC-VSATs, 245 VSATs are operating in the DOT network and another 102 are being added. High speed VSAT Network (HVNET) terminals are being offered on lease for data-only terminal and for data and voice services. Seventeen long distance subscriber telephone terminals are operational and 20 more are under consideration. The Bangalore-Delhi digital network with two 34 Mbps streams has been commissioned. Augmentation of existing eight Mbps connectivities amongst four metropolitan cities is planned by using digital channel multiplexing equipment. Captive satellite-based networks for National Thermal Power Corporation (NTPC), Gas Authority of India Ltd (GAIL), Nuclear Power Corporation (NPC), Indian Telephone Industries (ITI), Oil and Natural Gas Commission (ONGC), National Fertilisers Limited (NFL) and Coal India Limited (CIL) are operational. A CIL earth station at Poonch has been commissioned. The National Stock Exchange (NSE) VSAT network in extended C-band is operational. A number of captive government networks are also working with INSAT. More organisations are in the process of implementing their own captive networks using INSAT capacity. DOT has licensed a few private operators to provide value-added services to the public using the extended C-band. Mobile Satellite Services With the launch of INSAT-2C in December 1995, an S-band Mobile Satellite Service (MSS) was added to the INSAT system on an experimental basis. The following two classes of services were identified for MSS:
Television INSAT has been a major catalyst for the rapid expansion of television coverage in India. At present, 33 TV channels are operating through the C-band transponders of INSAT system as follows:
At present, 1,199 transmitters are working in the INSAT system out of which 1,104 transmitters (92 HPTs, 711 LPTs and 280 VLPTs) and 21 transposers are working in the DD-1 network and 90 TV Transmitters (39 HPTs, 45 LPTs and 6 VLPTs) are working in the DD-2 network. Three HPTs and two LPTs are used for other services. Educational
TV Programmes for university students are produced by Education Media Research Centres and Audio Visual Research Centres at different places. These programmes provide quality education within the reach of students in small towns and villages. Syllabus-based programmes for students enrolled in Indira Gandhi National Open University (IGNOU) are also relayed on this channel. Satellite
News Gathering and Dissemination Press Trust of India (PTI) is implementing a system to provide its news and information services at higher speed and increased volume and variety directly to a wider range of media and other users by utilising the broadcast facilities of INSAT. The project utilises a Radio Networking (RN) type of channel on one of the broadcast (CxS) transponders of the satellite. The PTI satellite news and facsimile dissemination project is working with 15 terminals (14 from PTI and one shared with AIR). Radio Networking There are 45 RN channels operating at present — 36 in S-band and 9 in C-band. Single channel captive uplink earth stations have been provided at 20 major programme producing centres (Srinagar, Ahmedabad, Bhopal, Cuttack, Patna, Guwahati, Shillong Thiruvananthapuram, Hyderabad, Bangalore, Jaipur, Shimla, Lucknow, Imphal, Kohima, Agartala, Aijwal, Chennai, Borivili and Hanagai). The captive earth station at Broadcasting House (BH), Mumbai is providing uplink of two Vividh Bharati channels. The earth station at Broadcast House at Delhi, has been augmented to provide uplink for seven RN carriers in CxS band and four in CxC band. Four RN carriers are uplinked from Sikanderabad station of DOT for national networking. C-band RN carriers are being received by 37 AIR stations. Transportable uplink terminals have been acquired by AIR for coverage of events taking place at remote locations and for relay of programmes directly from the spot via INSAT. AIR has also acquired DSNG RN terminals which are capable of uplinking CD quality music channel from any remote locations to a central place such as Delhi. Training
and Developmental Communication Andhra Pradesh is setting up
an integrated satellite network for the purpose of distance education,
health care and rural development. The network envisages Internet facilities
to villages in Andhra Pradesh. It is proposed to utilize IP based Digital
Transmission Technologies and DVB techniques In Gujarat, DOS has set up the up-link and studio with funding by State Government. The system is operational since August 2000. The Training programmes are being conducted regularly. In addition, engineering college network is now used on a daily basis. Various user departments have set up about 200 DRS. The Karnataka State Government
has decided to fund the total TDCC network for the state. The up-link
has been established and the studio installation is in progress. The conversion
of existing In Orissa, training programmes are being conducted for 5 to 10 days a month using the Fly-Away Terminal (FAT) located at the Cuttack Studio. The DRS network includes all 30 districts and 80 blocks in (Koraput-Bolangir-Kalahandi) districts. The network is proposed to be upgraded using VSAT options to cater to various other services such as E-governance, NRIS, DMS, etc. For the North Eastern Space Applications Centre (NE-SAC), several DRS have been installed and the training programme is expected to commence soon. For the Andaman and Nicobar Islands 7 locations are proposed to be covered in the first phase. Priority will be given for interactive training programmes for field functionaries, educational institutes and schools. For Goa, the uplink and studio have been established by the Goa University. The training of resource persons has been carried out. The DRS network covers 20 locations, which will be expanded to cover additional 80 locations. The follow up action on a pilot proposal for Jhalwad and Baran districts in Rajasthan is being taken up. An assessment of available studio equipment and other facilities has been made. New technologies are being used in TDCC network for multimedia lecture delivery and interactive distance learning. The network is being converted to digital mode to improve the capacity and quality of the system. It will also enable off-line downloading of lessons from servers at teaching end by the students. Jhabua Development Communications Project (JDCP) JDCP, which was started on November
1, 1996, is aimed at setting up an operational satellite-based broadcast
and interactive network for developmental communication and training.
More than 2000 programmes have been produced and broadcast in JDCP network
Telemedicine Meteorology INSAT-VHRR imageries are used by Doordarshan during news coverage and by newspapers as part of weather reporting. At present, repetitive and synoptic weather system observations over Indian Ocean from geostationary orbit are available only from INSAT system. The INSAT-VHRR data is available in near real-time at 32 Meteorological Data Dissemination Centres (MDDC) in various parts of the country. With the commissioning of direct satellite service for processed VHRR data, MDDC type of data can now be provided at any location in the country. One hundred meteorological Data Collection Platforms (DCPs) have been installed all over the country and also at Schiramacher, the Indian base station in Antarctica. The DCP services are provided using the Data Relay Transponders of INSAT-2B. Central Water Commission (CWC) and Snow and Avalanche Study Establishment (SASE) are using INSAT for real-time hydro-meteorological data collection in the Mahanadi and Chambal basins. Narmada Control Authority (NCA) is also planning to use the INSAT DRT data. About 250 Cyclone Warning Dissemination
System (CWDS) receivers have been installed A cooperative agreement has also been signed with the European meteorological satellite, EUMETSAT, for using data from METEOSAT-5 satellite, which is located at 63 degree east longitude in exchange for weather pictures of India’s INSAT. Satellite Aided Search
and Rescue (SAS&R) In addition, INSAT-2B is equipped with 406 MHz Search and Rescue payload, which picks up and relays alert signals originating from the distress beacons of maritime, aviation and land users. Based on the performance demonstrations of INSAT, the system has now been adopted as an integral part of the international COSPAS-SARSAT system for satellite-aided search and rescue operations complementing the LEOSAR system. Indian LUTs provide coverage to a large part of Indian Ocean providing distress alert services to Bangladesh, Bhutan, Kenya, Maldives, Nepal, Seychelles, Somalia, Sri Lanka and Tanzania. The operations of INMCC/LUT are funded by the participating agencies, namely, Coast Guard, Airports Authority of India (AAI) and Director General of Shipping and Services. INSAT-GEOSAR Local User Terminal (GEO LUT), located at Bangalore, is integrated with INMCC. The distress alert messages originating from the Indian service area are detected at INMCC which are passed on to Indian Coast Guard and Rescue Coordination Centres (RCCs) at Mumbai, Kolkata, Delhi and Chennai. Coast Guard, Navy and Air Force carry out the search and rescue activities. The INMCC is linked to the RCCs and other international MCCs through automatic telex and Aeronautical Fixed Telecommunication Network (AFTN). The Indian LUTs and MCC provide service round the clock and maintains the data base of all 406 MHz registered beacons equipped on Indian ships and aircraft. The Indian search and rescue system has detected and supported the following three real distress signals that resulted in the rescue of 40 people during the year.
Standard Time and Frequency
Signal Dissemination Satellite Navigation The SBAS is planned to be implemented in three phases—Technology Demonstration System (TDS), Initial Experimental Phase (IEP) and Final Operational Phase (FOP). The Indian SBAS system is expected to bridge the gap between the European EGNOS (European Geo-stationary Navigation Overlay System) and the Japanese MSAS (MTSAT Space Augmentation System) to provide seamless navigation of aircraft from west to east and vice versa. An organisational structure for implementation of the TDS and the Initial Experimental System has been formalised. When implemented, the Indian SBAS system is expected to play an important role in the introduction of satellite- based navigation services in Asia and the Pacific region. The Indian SBAS system will be known as GAGAN (GPS And GEO Augmented Navigation). |
|
|||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||