Isro to launch GSAT-7A communication satellite for IAF, Army on Dec 19

The satellite will be placed in the geostationary orbit and this communication satellite is expected to help the IAF interlink different ground radar stations, airbases and AWACS aircraft.

The Indian Space Research Organisation (Isro) is planning to launch a dedicated communication satellite for defence purposes next week.

GSAT-7A is a communications satellite which can be used by the Indian Air Force and the Indian Army.

Isro is all set to launch the communication satellite GSAT-7A on board the GSLV-F11 from Satish Dhawan Space Centre in Sriharikota on December 19, 2018. The satellite will weigh 2.2 tonnes and will be launched by the Geosynchronous Satellite Launch Vehicle (GSLV Mk II) rocket, said Isro.

The satellite will be placed in the geostationary orbit and this communication satellite is expected to help the IAF interlink different ground radar stations, airbases and AWACS (Airborne Warning And Control System) aircraft.

GSAT-7A is the 35th Indian Communication satellite built by Isro. The GSAT-7A spacecraft is configured on Isro’s standard I-2,000 Kg (I-2K) bus. The satellite is built to provide communication capability to the users in Ku-band over the Indian region. Total cost of the GSAT-7A is estimated to be in the region of Rs 6-8 billion and its life is estimated to be around nine years, according to Isro sources.

The satellite will enable the IAF to interlink different ground radar stations, ground airbase and airborne early warning and control (AWACS) aircraft, such as Beriev A-50 Phalcon and DRDO AEW&CS. The satellite will also enhance Network-centric warfare capabilities of the Indian Air Force and therefore enhance its global operations.

GSAT-7A is also expected to give a major push for drone operations as it would help the Navy reduce the reliance on on-ground control stations and take satellite-control of military unmanned aerial vehicles (UAV), which should help boost the range and endurance of the UAVs, said industry experts.

In addition to GSAT-7A, the IAF would also be getting the GSAT-7C in a few years, to boost the network-centric operations.

The GSAT 7 series was launched in 2013 as a dedicated communications satellite for the Indian Navy, which made the Navy completely independent of relying on foreign satellites.

GSAT 7 currently has a 2,000 nautical mile footprint and provides real-time inputs to Indian warships, submarines and maritime aircraft.

According to reports, India has around 13 military satellites, with most of them being remote-sensing satellites like the Cartosat-series and RISAT satellites placed in the near-earth orbit for better scanning of Earth.

However, some of the Indian military satellites are placed in the geostationary orbit. These are used for surveillance, navigation and communication purpose by the armed forces.

Business Standard

Kerala floods: How Isro satellites are playing a key part in saving lives

Data provided by the satellites is helping experts to predict the level of rains till then, what to expect in the next few hours and even about the situation in the forests and the water reservoirs.

Kerala Floods : Even as the unprecedented floods and landslides have devastated most parts of Kerala in the last fortnight, technologically the most helpful support the authorities are getting in handling the situation was updates from Indian Space Research Organisation (Isro) and its various satellites which kept their eyes open up from the atmosphere.

A set of remote sensing satellites and radar satellites has been taking pictures of various aspects of the situation in the flood-hit state from a distance of 400-800 kilometres from the Earth and sending it back with supportive data, which once crunched, helped the experts to predict the level of rains till then, what to expect in the next few hours and even about the situation in the forests and the water reservoirs.

For instance, ResourceSat-2, launched on April 20, 2011, has proved to be helpful in taking pictures on the forestry and normal terrain and how the water bodies are while ScatSat-1 can track the wind, how it flows over the sea and over the land which helps to forecast the weather. Insat 3DR, another satellite together with others can communicate how clouds are positioned and with the help of ScatSat-1, experts can come to a conclusion on how fast they are moving considering the wind speed. Insat satellites, which are geostationary, would send data in every half an hour from the atmosphere, which can give an update to the ground station.

"Satellite plays important role in detection and monitoring of flood situations over large regions. Optical remote sensing from geostationary platform (Insat-3D/3DR) provides rapid and valuable information on cloud patterns and meteorological parameters (rainfall); however, unable to image the surface water conditions in presence of cloud," says Isro.

Microwave remote sensing techniques have a unique advantage in which electromagnetic radiation penetrate the clouds and senses the surface hydrological characteristics. The data from ScatSat-1 (launched by PSLV-C35 on September 26, 2016) was used for the detection of the flood situations over India. ScatSat-1 is a continuity mission for Oceansat-2 Scatterometer for Ocean weather forecasting, cyclone detection, and tracking.

ScatSat-1 observations in Ku-band for backscattering and brightness temperatures have been analyzed for flood detection and monitoring over India with special emphasis in Gujarat and southern parts of Rajasthan in the past. Merging of backscattering and brightness temperature data helped to delineate the regions, which were flooded, partially submerged or existed in different soil wetness conditions (saturated or dry).

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