Context: Recently, the Ministry of Defense has given the Acceptance of Necessity for the GSAT-7B satellite. This satellite will be a dedicated satellite for the Indian Army.

• The satellite would help the Indian Army enhance its surveillance in border areas.
• Currently, India has only two dedicated military satellites — the GSAT-7 (Rukmini) and GSAT-7A (Angry Bird) — used by the Indian Navy and Air Force respectively.

What are the GSAT 7 series satellites?

• GSAT 7 satellites are advanced satellites developed by the ISRO to meet the communication needs of the defence services.
• The satellite was injected into a geosynchronous transfer orbit (GTO) of 249 km perigee (nearest point to earth), 35,929 km apogee (farthest point to earth) and an inclination of 3.5 degree with respect to the equator.
• The GSAT 7 satellite was launched in August 2013 from an Ariane 5 ECA rocket from Kourou in French Guiana.
• It is a 2,650 kg satellite which has a footprint of nearly 2,000 nautical miles in the Indian Ocean region.

Utility of this satellite

• This satellite is mainly used by the Indian Navy for its communication needs.
• The GSAT 7 provides a gamut of services for military communication needs, which includes low bit voice rate to high bit rate data facilities, including multi-band communications.
• Named Rukmini, the satellite carries payloads in UHF, C-band and Ku-band, and helps the Navy to have a secure, real time communication link between its land establishments, surface ships, submarines and aircraft.

What will be the role of the GSAT 7B satellite?

• The GSAT 7B will primarily fulfil the communication needs of the Army.
• Currently, the Army is using 30 per cent of the communication capabilities of the GSAT 7A satellite, which has been designed for the Indian Air Force (IAF).
• The GSAT 7B will also help the Army enhance its surveillance in border areas.
• While many features of this satellite are still a closely guarded secret, it is expected that the state of the art, multi-band, military-grade satellite shall be a shot in the arm for the communication and surveillance needs of the Army.

What is the role of the GSAT 7A satellite, which is already operational?

• The GSAT 7A was launched in 2018 from the Satish Dhawan Space Centre in Sriharikota.
• It has gone a long way in boosting the connectivity between the ground radar stations, airbases and the airborne early warning and control aircraft (AEW&C) of the IAF.
• It also helps in satellite controlled operations of unmanned aerial vehicles (UAVs) which gives a great deal of reliability to the operations as compared to ground-controlled operations.
• This satellite has 10 channels in Ku band with switchable frequency for mobile users, one fixed Gregorian or parabolic antenna, and four steerable antennae.

Future plans
A GSAT 7C satellite is on the cards for the IAF, and a proposal to this effect was cleared by the DAC in 2021.

• This satellite would facilitate real time communication with IAF’s software defined radio communication sets.
• It will increase the capability of the IAF to communicate beyond the line of sight in a secure mode.

What other kinds of military satellites does India have?

• An Electromagnetic Intelligence Gathering Satellite (EMISAT), developed by ISRO, was launched in April 2020 through a Polar Satellite Launch Vehicle (PSLV-C45).

It has an Electronic Intelligence (ELINT) package called Kautilya, which allows the interception of ground-based radar and also carries out electronic surveillance across India.

• The ELINT package provides the capability in direction-finding of radar and fixing their locations.
• It is placed in a 748-km orbit, and is said to be based on the Israeli satellite system.
• This satellite circles the globe pole-to-pole, and is helpful in gathering information from radars of countries that have borders with India.

India also has a RISAT 2BR1 synthetic aperture radar imaging satellite, which was launched in December 2019 from Sriharikota.

• It has the capability to operate in different modes including very high resolution imaging modes of 1×0.5 metre resolution and 0.5×0.3 m resolution with a swath of 5-10 km.