Quote:CARTOSAT-2[center]
CARTOSAT-2, the twelfth in the Indian Remote Sensing (IRS) satellite series, is an advanced remote sensing satellite capable of providing scene-specific spot imagery. CARTOSAT-2, launched on January 10, 2007 by PSLV-C7, carries a single panchromatic camera onboard capable of providing better than 1-meter spatial resolution imagery, with a swath of 9.6 km. The satellite has high agility with capability of steering along and across the track up to + 450 to facilitate imaging of any area more frequently. It was placed in a sun synchronous polar orbit of a nominal altitude of 630 km with a re-visit of 4-5 days and can be brought to a special orbit of 560 km with revisit periods of 4 days and 1 day respectively.
Cartosat-2 satellite has been functioning well, providing operational services to the user community. The data from the satellite is being used for cartographic applications at the cadastral level, urban and rural infrastructure development and management, as well as applications in Land Information System (LIS).
[center]Phased Array Antenna of Cartosat-2
developed at ISAC
Forthcoming Satellites
CARTOSAT-2B
The Cartosat-2B satellite, a follow on of Cartosat-2A, weighing around 690 kg, is configured to provide multi-scene imaging capability during a pass. The advanced remote sensing satellite will be carrying onboard a single panchromatic camera providing scene specific spot imageries for cartographic and a host of other civilian applications. The satellite is highly agile having a capability of steering along and across the track up to ñ 450. It will be placed in a sun synchronous polar orbit of a nominal altitude of 630 km with a re-visit period of 4-5 days. There is a provision to bring the satellite to a special orbit of 560 km with a revisit period of 1 day. The panchromatic camera is designed to provide better than 1 m spatial resolution imageries with a swath of 9.6 km. The satellite is designed for an operational life of 5 years. The spacecraft is under integration and will be launched by PSLV in the first quarter of 2010.
RISAT - 1
Radar Imaging Satellite (RISAT-1) mission will have a C-band Synthetic Aperture Radar (SAR) payload, operating in a multi-polarisation and multi-resolution mode. SAR, being an active sensor, operating in the microwave range of electromagnetic spectrum, provides target parameters such as dielectric constant, roughness, and geometry, and has the unique capability for day-night imaging, and imaging in all weather conditions including fog and haze and also provides information on soil moisture. The SAR payload is based on an active phased array technology using Transmit / Receive (TR) modules, which would provide necessary electronic agility for achieving the multi-mode capability, providing spatial resolutions of 1 m to 50 m, and 10 to 240 km swath modes to cater to different applications. The Local Time of RISAT is 06:00 hours at the descending node.
The development of complex technologies pertaining to phased array antenna of 6 m x 2 m size hosting 20736 radiative elements, 288 TR module pairs feeding the radiative elements, a number of power converters supplying power to all these elements, signal distribution and calibration network, range and azimuth compression and data compression as well as handling very high average DC power of 4.7 KW during payload operations etc., form part of the overall mission, hitherto not attempted in IRS satellites. Ground data processing systems with large computational requirements is under development. The satellite weighing around 1850 kg is in the final stages of development for launch by PSLV-XL during third quarter of 2010 into a 536 km orbit with 25 days repetitivity with an added advantage of 12 days inner cycle for CRS mode.
RESOURCESAT-2
Resourcesat-2 is a follow on mission to Resourcesat-1 to provide data continuity. Compared to Resourcesat-1, LISS-4 multispectral swath has been enhanced from 23 km to 70 km based on user needs. Suitable changes including miniaturisation in payload electronics have been incorporated in Resourcesat-2. Resourcesat-2 is slated for launch during 2010.
Megha-Tropiques
(Megha means cloud in Sanskrit and Tropiques means tropics in French) is aimed at understanding the life cycle of convective systems and to understand their role in the associated energy and moisture budget of the atmosphere in the tropical regions. ISRO and French National Space Centre (CNES) signed a Memorandum of Understanding (MOU) in 2004-05 to proceed with the development and implementation of Megha-Tropiques. The satellite will carry the following scientific instruments:
ISRO is building the Megha-Tropiques spacecraft using IRS platform and launch it using PSLV into 867 km orbit at an inclination of 20 degrees with respect to the equatorial plane. ISRO will also control the satellite in orbit and also receive, process and distribute the scientific data obtained from the satellite. All flight structure elements have been tested and assembled. Mainframe subsystems are in final stages of realisation. The electronic hardware for MADRAS payload is delivered for assembly. Testing of SCARAB and SAPHIR payloads is completed. The launch of Megha-Tropiques is planned during the fourth quarter of 2010.
- Microwave Analysis and Detection of Rain and Atmospheric Structures (MADRAS), an Imaging Radiometer to be developed jointly by CNES and ISRO
- SAPHIR, a six channel Humidity Sounder
- SCARAB, a four channel Scanner for Radiation Budget Measurement
- GPS-ROS - GPS Radio Occultation System to provide vertical profiles of temperature and humidity of the earth's atmosphere
SARAL
The Satellite for ARGOS and ALTIKA (SARAL) is a joint ISRO - CNES mission, and will be launched by PSLV into a sun-synchronous, 6 am - 6 pm orbit at an altitude of around 800 km. The Ka band altimeter, ALTIKA, provided by CNES operates at 35.75 GHz. A dual frequency total power type microwave radiometer (23.8 and 37 GHz) is embedded in the altimeter to correct tropospheric effects on the altimeter measurement. Doppler Orbitography and Radiopositioning Integrated by Satellite (DORIS) on board enable precise determination of the orbit. A Laser Retroreflector Array (LRA) helps to calibrate the precise orbit determination system and the altimeter system several times throughout the mission.
SARAL / ARGOS Data Collection System (DCS) represents a joint contribution of ISRO and CNES to the development and operational implementation of the global ARGOS Data Collection System. The main objective is to receive data from Data Collection Platforms and transmit these to the ARGOS Ground Segment, for subsequent transmission to the ARGOS Data Processing and Distribution Centre in Toulouse, France. In addition, ARGOS Payload allows the transmission of short messages directly to Data Collection Platforms equipped with a receiver.
SARAL payload will be accommodated in the mini-satellite bus ranging between 400-450 kg class, named as SSB-1 (Small Satellite Bus). SARAL will provide Data Products to the operational and research user communities, in support of Marine meteorology and sea state forecasting; Operational oceanography; Seasonal forecasting; Climate monitoring; and Ocean, Earth system and climate research. Preliminary Design Review has been completed. SARAL simulator has been delivered to CNES. Spacecraft Mainframe systems are under fabrication and payload delivery is expected in May 2010. The satellite launch is planned during 2011.
Ground Segment
ISRO Telemetry, Tracking and Command Network (ISTRAC) with its headquarters at Bangalore is providing TTC and mission control support to launch vehicle missions and near earth orbiting satellites through an integrated network of ground stations at Bangalore, Lucknow, Sriharikota, Port Blair, Thiruvananthapuram Mauritius, Tromso and Svalbard (Norway) & Troll (Antartica) and Biak (Indonesia), has a multimission Spacecraft Control Centre at Bangalore.
ISTRAC provides:
During the year, ISTRAC provided the launch, preliminary orbit determination and on-orbit support for the launch of RISAT-2 and OCEANSAT-2 satellites. It continued to track, monitor and control TES, Oceansat-1, Resourcesat-1, CARTOSAT-1, CARTOSAT-2, CARTOSAT-2A, IMS-1, RISAT-2 and OCEANSAT-2. Remote sensing payload operations were carried out during the year on IRS-1C and IRS-1D over Indian stations at Shadnagar, and also over 15 Foreign Data Reception Stations (FDRS). About 350 to 400 payload operations are carried out per month for each satellite. Payload operations of OCEANSAT-1 were carried out over Indian station. IRS-P3 payload was operated about 250 times per month over Shadnagar in India and Neustralitz (Germany), Wallops (USA) and Maspolamas (Spain). TES Payload (PAN) operations are regularly carried out over India. [/center]
- Telemetry Tracking and Command (TTC) support to ISRO launch vehicle missions from Satish Dhawan Space Centre SHAR from lift-off till satellite injection, down range tracking support for satellite injection monitoring and Preliminary Orbit Determination (POD)
- TTC support including house-keeping data acquisition throughout the mission life for low earth orbiting satellites and their health monitoring and control operations
- Scientific payload data reception and processing for payload scientists ISTRAC also provides TTC support to international space agencies under commercial agreements through ANTRIX Corporation. ISTRAC has also established the SPACENET, connecting various ISRO Centres.
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