Satellite News Gathering and Dissemination
Satellite News Gathering using INSAT system enables on the spot real-time news coverage and important events at different locations for transmission to a Central Station at Delhi or to State Capitals for rebroadcast over respective DD channels. Prasar Bharati has 13 C-band and
18 Ku-band Digital Outdoor-Broadcast DSNG terminals operating through INSAT, IS-10 (INTELSAT) and IS-906 (INTELSAT) network. 15 more DSNGs in C-Band are proposed to be introduced in the network by DD.

Eight transportable uplink terminals (DSNG) are being utilised by AIR for coverage of events taking place at remote locations and for relay of programmes directly from the spot via INSAT. These terminals are capable of uplinking CD quality music channel from any remote location.

Radio Networking
Radio Networking (RN) through INSAT provides a reliable high-fidelity programme channels for national as well as regional networking. At present, 235 All India Radio (AIR) stations have been equipped with S-band receive terminals out of which around 200 AIR stations have been equipped to receive C-band Analogue and Digital RN carriers also and rest of the stations are going to be equipped with digital C-band RN Terminals by the end of the 11th Five Year Plan.

A total of 85 RN channels are being up-linked at present. For this, AIR is utilising one S-band transponder (S2) and one C-band transponder of INSAT-3C. A total of 90 carriers in CxC band are being envisaged for up-linking by utilising one full transponder of INSAT-3C.

In AIR network, a total of 32 earth stations are present with facility to uplink in both CxS and CxC band frequency. The Central earth station at Broadcasting House, New Delhi, has been augmented to up-link 26 RN carriers in CxS and CxC band.

At present, AIR uplinks 21 radio channels on DTH platform in Ku-band with TV carriers from Todapur, New Delhi on INSAT-4B. Efforts are underway to augment this to 30 channels, and efforts are also being made to uplink 6 radio channels on DTH C-Band to cover Andaman Nicobar areas.

Telecommunications
A total of 883 Earth stations and 1,37,618 VSATs telecommunication terminals of various sizes and capabilities are operating in INSAT telecommunications network providing 9709 two-way speech circuits and providing transmission backhaul point to point connectivities. These include 101 BSNL, 231 Earth stations +435 VSATs for government users and 551 Earth stations +1,32,137 VSATs Closed User Group(CUG)/Commercial VSAT operators earth stations. 46 Multi Channel per Carrier (MCPC) VSATs and 5000 Ku band VSATs under HVNET are working with BSNL. A total of 1,37,618 CUG VSATs are operating through INSAT.

Captive satellite-based networks for National Stock Exchange, Bombay Stock Exchange, National Thermal Power Corporation, Gas Authority of India Ltd., Nuclear Power Corporation, Oil and Natural Gas Commission, National Fertilizers Limited, Coal India Limited, DPNET, ERNET, Karnataka Power Transmission Corporation Limited, ITI, GNFC, BPCL, Indian Railway Project Management Unit and ICAR, West Bengal State Electricity Distribution Co. Ltd, IOCL, Khazane Net are operational. A number of captive private networks are also working with INSAT. More organisations are in the process of implementing their own captive networks using INSAT.

Mobile Satellite Services
S-band Mobile Satellite Service (MSS) payloads are supported on INSAT-3C and GSAT-2. The following two classes of services were provided using MSS:

INSAT Type-D Service
A small portable satellite terminal that works with INSAT for voice/data communication has been developed with the participation of Indian industries. The terminal is useful for voice communication, especially during disasters when other means of communication break down. It can be used from any location in India for emergency communication. Transmit and receive frequencies of the terminal are in S-band. This service is mainly used by government users.

The portable terminal connects to the EPABX at central hub station through satellite channel and hence could be considered as an extension of EPABX and call could be made between local phones through EPABX. Calls could also be made between the portable terminals.

INSAT Type-C Service (Reporting system)
This consists of low bit rate one-way reporting service using shared channels with hand-held terminals. Short messages from this terminals are relayed through the satellite to the hub and are automatically forwarded to the respective user headquarters via Fax or data links. There is a provision to attach a GPS receiver to the reporting terminal for position information.

Meteorology
The meteorological data of INSAT system is processed and disseminated by INSAT Meteorological Data Processing System (IMDPS) of India Meteorological Department (IMD). The products derived from the satellite data include: Cloud motion vectors, Water Vapour, sea surface temperature, long-wave radiation, quantitative precipitation estimates, Upper tropospheric Humidity and Normalised Difference Vegetation Index. Cloud images in the Visible, Infra-red and Water Vapour Channel are obtained from the satellites. The products are used for weather forecasting, both synoptic and numerical weather prediction.

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. INSAT VHRR data is available in near real-time at 40 Digital Meteorological Data Dissemination (DMDD) stations in various parts of the country as well as in neighboring countries Nepal, Maldives and Srilanka.

With the commissioning of direct satellite service for processed VHRR data, DMDD type of data can be provided at any location in the country.
IMD has installed 522 meteorological Data Collection Platforms (DCPs) and other agencies have installed about 1000 DCPs all over the country.

IMD has also installed 356 Automatic Rain Gauge (ARG) Stations. DCP and ARG services are operational by using the Data Relay Transponders (DRT) of Kalpana-1 and INSAT-3A. ISRO has indigenously developed a low cost automatic weather station for deployment in the country in large numbers.

For quick dissemination of warnings against impending disaster from approaching cyclones, specially designed receivers have been installed at the vulnerable coastal areas in Andhra Pradesh, Tamil Nadu, Orissa, West Bengal and Gujarat for direct transmission of warnings to the officials and public in general using broadcast capability of INSAT. IMD’s Area Cyclone Warning Centres generate special warning bulletins and transmit them every hour in local languages to the affected areas. 352 such receiver stations have been installed by IMD. Out of these 100 are Digital CWDS (DCWDS) based on advanced technology. Efforts are on to replace the network of CWDS/DCWDS by ISRO developed DTH modified type CWDS.

Satellite Aided Search and Rescue (SAS&R)
India is a member of the international COSPAS-SARSAT programme for providing distress alert and position location service through LEOSAR (Low Earth Orbit Search And Rescue) satellite system. Under this programme, India has established two Local User Terminals (LUTs), one at Bangalore and the other at Lucknow. The Indian Mission Control Centre (INMCC) is located at ISTRAC, Bangalore.

INSAT-3A, located at 93.5 deg East, is equipped with 406 MHz Search and Rescue payload that picks up and relays alert signals originating from the distress beacons of maritime, aviation and land users. INSAT and GOES systems have become an integral part of the COSPAS-SARSAT system and they complement the LEOSAR system.

Indian LUTs provide coverage to a large part of Indian Ocean region rendering distress alert services to Bangladesh, Bhutan, Maldives, Nepal, Seychelles, Sri Lanka and Tanzania. The operations of INMCC/LUT are funded by the participating agencies, namely, Coast Guard, Airports Authority of India (AAI) and Directorate General of Shipping and Services.

INSAT GEOSAR Local User Terminal (GEO LUT) is established at ISTRAC, Bangalore and integrated with INMCC. The distress alert messages concerning the Indian service area, detected at INMCC, are passed on to Indian Coast Guard and Rescue Coordination Centres at Mumbai, Kolkata, Delhi and Chennai. The search and rescue activities are carried out by Coast Guard, Navy and Air Force. INMCC is linked to the RCCs and other International MCCs through Aeronautical Fixed Telecommunication Network (AFTN). The Indian LUTs and MCC provide service round the clock and maintain the database of all 406 MHz registered beacons equipped on Indian ships and aircraft.

Development of indigenous search and rescue beacons has been completed, and is now in certification phase. Shortly it will be released to the Indian fishermen community.

During the year 2010, INMCC provided search and rescue support to 4 distress incidents through INSAT GEOSAR system and contributed in saving 12 lives (within INSAT coverage).

During 2010, about 4485 new radio beacons have been added in Indian database that shows rapid growth of the users in India (3459 on ships/boats, 846 on aircraft, 180 Personal). Till date, there are about 550 registered user agencies (Maritime & Aviation) in India with more than 9801 radio beacons in use.

Migration from LEOSAR and GEOSAR to MEOSAR system has been undertaken. Design of an upcoming MEOSAR system is ready and will be implemented in 2 years.

Standard Time and Frequency Signal Dissemination Services
A Standard Time and Frequency Signal Dissemination Service using a Radio Networking (RN) carrier on INSAT-3C is being operated by the National Physical Laboratory. This service is available round-the-clock in a broadcast mode at a downlink frequency in S-band and is receivable on a set up consisting of a 2.4 m diameter antenna, a front-end converter, an FM demodulator and a microprocessor controlled signal decoder. The service consists of a train of 5 KHz bursts signal, which is frequency modulated on the carrier. The time has a precision of better than one microsecond and accuracy of better than 20 microseconds.

GPS AIDED GEO AUGMENTED NAVIGATION (GAGAN)
The Indian Satellite Based Augmentation System (SBAS) called GAGAN has entered into the implementation of Final Operational Phase (FOP) since July 2009 and is planned to be ready for operations and certification by June 2013.

The GAGAN-FOP would have a total of 15 INRES, 3 INLUS, 2 INMCC, 2 DCN and 3 GEO satellites configuration. Currently, the major ground equipments are at various stages of installation, site acceptance and integration. One of the major elements in ensuring the APV-1.0/1.5 performance for GAGAN is the selection of ionosphere model (IGM-MLDF), which has been developed by ISAC and is currently under implementation in the operational system.

The next major milestone in GAGAN is the conduct of PSAT (Preliminary System Acceptance Testing) which has been successfully completed in Dec 2010. The first GAGAN navigation payload is slated on GSAT-8 scheduled in the second quarter of 2011. The second GAGAN payload is scheduled to be launched on GSAT-10 in the first quarter of 2012. The third GAGAN payload is planned on another GEO satellite.

INDIAN REGIONAL NAVIGATION SATELLITE SYSTEM (IRNSS)
IRNSS constellation consists of seven satellites. Three satellites will be placed in Geostationary orbit (GEO) at 34°E, 83°E & 131.5°E and two satellites each will be placed in the Geosynchronous orbit (GSO) with equatorial crossing at 55°E and 111.5°E with an inclination of 29° to the equator. Two spare satellites are also planned. IRNSS provides two services – a Standard Positioning Service (SPS) for common civilian users and a Restricted Service (RS) for special authorised users on L5 and S bands.

Navigation Payload configuration is frozen and Preliminary Design Review (PDR) has been completed. The EVM model is being integrated and tested. The proto flight model and flight model subsystems are under realisation. The EM and PFM models of Rb Atomic Frequency Standards and Atomic Clock Monitoring Units have been delivered. IRNSS Signal and Data structure has been prepared after extensive study and review by groups at the work centers and reviewed.

The civil construction work for the Navigation Control Centre at Bangalore and the Satellite Control Facility at Hassan is in progress. The associated Servers, Data Archival systems, Communication units, Work terminals have been procured and are under installation. Multipath and Noise Survey has been completed at most of the Reference Stations. The TT&C stations and CDMA ranging stations are being established at the designated places.

The satellites of the constellation are configured identically, with each spacecraft weighing 1380 kg. Fabrication of six structural cylinders is completed. Efforts are on to productionise the standard subsystems. The spacecraft is basically configured with I-1K Bus to be compatible with launch onboard PSLV.

The navigation software for IRNSS is being indigenously developed at ISRO Satellite Centre. As a part of this activity, many analysis modules have been developed and used in various studies like Coverage Studies, Error Analysis, Uplinking scheme for Navigation Parameters, CDMA Ranging Analysis, etc. The realisation of the Payload Engineering Model is progressing satisfactorily.

The breadboard model of user receiver is being realised. Efforts are on to develop the IRNSS Signal Simulator to be used for testing of IRNSS receivers. ISRO is collaborating with NPL to realise space qualified Rb Atomic Frequency Standard.