INSAT 3D

India’s advanced weather satellite INSAT-3D, launched in the early hours of July 26, 2013 from Kourou, French Guyana, was successfully placed in Geosynchronous orbit after three orbit raising manoeuvres commanded from ISRO`s Master Control Facility at Hassan. INSAT-3D is an advanced weather satellite of India configured with improved Imaging System and Atmospheric Sounder. INSAT-3D is designed for enhanced meteorological observations, monitoring of land and ocean surfaces, generating vertical profile of the atmosphere in terms of temperature and humidity for weather forecasting and disaster warning.

It carries four payloads -

• 6 channel multi-spectral Imager
• 19 channel Sounder
• Data Relay Transponder (DRT)
• Search and Rescue Transponder

The payloads of INSAT-3D will provide continuity and further augment the capability to provide various meteorological as well as search and rescue services. INSAT-3D has a lift-off mass of 2060 kg, which includes about 1125 kg of propellant. The propellant carried by INSAT-3D is mainly required to raise the satellite from the Geosynchronous Transfer Orbit (GTO) to its final Geostationary Orbit and to maintain the satellite attitude during its life. INSAT-3D is based on ISRO’s two Tonne Class platform (I-2K bus) employing light-weight structural elements like Carbon Fibre Reinforced Plastic (CFRP). The satellite has a solar panel generating 1164 Watts of power.

INSAT-3D was launched into a Geosynchronous Transfer Orbit (GTO) by Ariane-5 VA-214 launch vehicle from Kourou, French Guiana. The solar panel of the satellite deployed immediately after its injection into GTO. Following this, ISRO‘s Master Control Facility (MCF) at Hassan takes control of the satellite and performed the initial orbit raising maneuvers using the Liquid Apogee Motor (LAM) on-board the satellite, finally placing it in the circular Geostationary Orbit. Later, INSAT-3D was put into its final orbital configuration and positioned at 82 deg East longitude. The designed in-orbit operational life of INSAT-3D is 7 years.

For meteorological observations, INSAT-3D carries a multi-spectral Imager (optical radiometer) capable of generating the images of the earth in six wavelength bands significant for meteorological observations, namely, visible, shortwave infrared, middle infrared, water vapor and two bands in thermal infrared regions. The Imager will generate images of the earth disk from geostationary altitude of 36,000 km every 26 minutes and provide information on various parameters, namely, outgoing long-wave radiation, quantitative precipitation estimation, sea surface temperature, snow cover, cloud motion winds, etc. Imager payload is an improved version of VHRR flown on INSAT-3A and Kalpana-1 satellites with significant improvements in spatial resolution, number of spectral channels and functionality.

INSAT-3D also carries a newly developed 19 channel sounder, which is the first such payload to be flown on an ISRO satellite mission. The Sounder has eighteen narrow spectral channels in shortwave infrared, middle infrared and long wave infrared regions and one channel in the visible region. It will provide information on the vertical profiles of temperature, humidity and integrated ozone. These profiles will be available for a selected region over Indian landmass every one hour and for the entire Indian Ocean Region every six hours. Data Relay Transponder (DRT) on-board INSAT-3D will be used for receiving meteorological, hydrological and oceanographic data from remote, uninhabited locations over the coverage area from Data Collection Platforms (DCPs) like Automatic Weather Station (AWS), Automatic Rain Gauge (ARG) and Agro Met Stations (AMS). The data is relayed back for down linking in extended C-Band.

INSAT-3D is equipped with a Search and Rescue payload (operating in 406 MHz) that picks up and relays the alert signals originating from the distress beacons of maritime, aviation and land based users to the Indian Mission Control Centre (INMCC) located at ISRO Telemetry, Tracking and Command Network (ISTRAC), Bangalore. The major users of Satellite Aided Search and Rescue service in India are the Indian Coast Guard, Airports Authority of India (AAI), Directorate General of Shipping, Defence Services and fishermen. The Indian service region includes a large part of the Indian Ocean region covering India, Bangladesh, Bhutan, Maldives, Nepal, Seychelles, Sri Lanka and Tanzania for rendering distress alert services.

Indian Space Research Organization (ISRO) has taken up the responsibility of end-to-end reception and processing of INSAT-3D data and derivation of meteorological parameters with India Meteorological Department (IMD), New Delhi. An indigenously designed and developed INSAT-3D Meteorological Data Processing System (IMDPS) is installed and commissioned at IMD, New Delhi with a Mirror Site at Space Applications Centre, Bopal, Ahmedabad. IMDPS will cater to the processing of all data transmitted by the Imager and Sounder payloads. The data archival and dissemination is through IMD, New Delhi and Meteorological and Oceanographic Satellite Data Archival Centre (MOSDAC) websites. IMDPS comprises of three major sub-systems - (i) Data Acquisition and Quick Look Display System (ii) Data Products System and (iii) Geo-Physical Parameter Retrieval System.

In its tenth flight (GSLV-F05) conducted 08 September 2016, India's Geosynchronous Satellite Launch Vehicle, equipped with the indigenous Cryogenic Upper Stage (CUS), successfully launched the country's weather satellite INSAT-3DR, into a Geosynchronous Transfer Orbit (GTO). The achieved orbit is very close to the intended one. The launch took place from the Second Launch Pad at the Satish Dhawan Space Centre SHAR (SDSC SHAR), Sriharikota, the spaceport of India. This was the first operational flight of GSLV equipped with CUS and the fourth to carry the indigenous CUS. The GSLV flight was the third consecutive success achieved by GSLV carrying indigenous CUS and the 2211 kg INSAT-3DR is the heaviest satellite to be launched from the Indian soil.