RESOURCESAT-1
Resourcesat-1, the tenth satellite in IRS series, was launched on board PSLV-C5 in October 2003. It was placed in an 820 km high polar Sun Synchronous Orbit. Resourcesat-1 carries three cameras:
* A high resolution Linear Imaging Self Scanner (LISS-4) operating in three spectral bands in the Visible and Near Infrared Region (VNIR) with 5.8 metre spatial resolution with 70 km (mono) and 23 km (multispectral) swath and steerable up to + 26 deg across track to obtain stereoscopic images and achieve five day revisit capability
* A medium resolution LISS-3 operating in three spectral bands in VNIR and one in Short Wave Infrared (SWIR) band with 23.5 metre spatial resolution with 142 km swath
* An Advanced Wide Field Sensor (AWiFS) operating in three spectral bands in VNIR and one band in SWIR with 56 metre spatial resolution and a combined swath of 730 km achieved through two AWiFS cameras
In addition, RESOURCESAT-1 has 120 Gigabits of on-board memory that allows for out-of-contact imaging. Uniqueness of this satellite is the availability of simultaneous multispectral data at three spatial resolutions from the same platform with scene coverage varying from 576 sq km to 19,600 sq km to 5,42,000 sq km.
The images are being used for advanced applications like vegetation dynamics, crop yield estimates, disaster management support, etc.
OCEANSAT-1
OCEANSAT-1, intended to study physical and biological aspects of oceanography, was launched onboard PSLV-C2 on May 26, 1999. It carries an Ocean Colour Monitor (OCM) and a Multifrequency Scanning Microwave Radiometer (MSMR). OCM operates in 402-422, 433-453, 480-500, 500-520, 545-565, 660-680, 745-785 and 845-885 nm bands with 360-meter spatial resolution and 1420 km swath. OCM data is collected over the Indian region and also over International ground stations.
Technology Experiment Satellite (TES)
TES was launched on board PSLV-C3 on October 22, 2001. The satellite was intended to demonstrate and validate technologies that could be used in the future cartographic satellite missions. Some of the technologies demonstrated in TES were: attitude and orbit control system, high torque reaction wheels, new reaction control system with optimised thrusters and a single propellant tank, light weight spacecraft structure, solid state recorder, X-band phased array antenna, improved satellite positioning system, miniaturized TTC and power system and two-mirror-on-axis camera optics. TES carries a panchromatic camera with a spatial resolution of 1 m and swath of 13 km. The satellite has been functioning well even after its intended mission life.
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 ± 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:
* 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
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.
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:
* 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.
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.
Satellite Data Acquisition and Processing
The National Remote Sensing Centre (NRSC), Hyderabad is the nodal agency for satellite remote sensing data reception, archival, processing and dissemination in the country. NRSC acquires and processes data from all Indian remote sensing satellites like CARTOSAT-1, CARTOSAT-2, RESOURCESAT-1, IRS-1D, OCEANSAT-1, OCEANSAT-2 and IMS-1. NRSC Shadnagar Ground station acquires data from various Indian remote-sensing satellites and few foreign satellites. The station receives around 22 passes regularly at a station efficiency of 99%. As per the Remote Sensing Data Policy, NRSC is the national agency identified for acquisition/distribution of all the satellite data within India. Accordingly, NRSC is disseminating satellites data from Indian and foreign satellites to Indian users. During the year, more than 29,000 data products were disseminated to Indian as well as foreign users.
During the year, the ground segment has been upgraded for reception, processing and product generation. RISAT-1 and RISAT-2 data reception station and a small terminal for IMS satellite data reception have been established. Integrated Multi-mission Ground segment for Earth Observation Satellites (IMGEOS) is conceived, with an objective to have a highly reliable, easily adaptable system to future mission requirements using state-of-art technologies and world class infrastructure towards meeting the requirement of reduced turnaround time for the data product generation.
The preparatory activities for setting up of Oceansat-2 data reception at INCOIS, Hyderabad, a mobile transportable ground receiving station to RISAT-2 data for NTRO has been also developed. The Algiers ground station is being upgraded to receive ALSAT-2A/2B data. Installation and configuring of Resourcesat -1 data processing facility was taken up at Cuiaba station in Brazil as part of the ISRO-INPE (National Institute for Space research, Brazil) co-operative agreement.
Aerial Remote Sensing
The aerial remote sensing facility of NRSC offers value-added services like aerial photography and digital mapping, infrastructure planning, scanner surveys, aeromagnetic surveys, large scale base map, topographic and cadastral mapping, etc. Two aircraft with modern navigational aids, aerial cameras and sensors are available to carry out these activities.
NRSC has inducted the Large Format Digital Metric Camera for Aerial Services and Digital Mapping activities. The Ultracam D camera, with its maximum resolution of 3 cm is one of the leading frame type digital cameras and is expected to give a new impetus to digital photo-grammetric applications. Both the existing aircraft were modified for installation of LFDC system and the system was accepted after test sorties.
400 hours of flying was completed during Apr- Dec 2009 and is expected to touch 550 hrs by March 31, 2010. DMSAR flying over Bihar was completed for 85,000 sq kms (post flood). Aerial photography tasks covering Bangalore (2,500 sq kms), Kolkata (2,300 sq kms and Karimnagar district of A.P. (8,000 sq kms out of 15,000 sq kms) were completed. Under NUIS project, Aerial photography has been completed for 67 towns and planned to be completed for 146 towns. Both the existing aircraft were modified for installation of LFDC system and the system was accepted after test sorties. The test data sets were collected and analyzed in different resolutions of 5 & 10 cm Ground Sampling
LFDC system installed in NRSC aircraft
Distance (GSD) for Shadnagar site, 10 cm GSD for Kamareddy town (Nizamabad district, AP), and 30 & 50 cm GSD for part of Hyderabad. Processing of ALTM data of Sabari basin in AP (800 sqkm) and Mahanadi basin in Orissa (8000 sqkm) are in progress and planned to be completed by March 2010. ALTM - DC data survey for Kosi and Bhagmati basin, Bihar (12100 sq km) is in progress. 3D geospatial database generation for NIC in 1:1000 scale from 1:6000 scale aerial photographs for Hyderabad, Bangalore and Kolkata cities are in various stages of completion.
The recently procured Ultracam D Large Format Digital Camera has been successfully put into use during the search and rescue operations of the missing helicopter in Kurnool district for Government of Andhra Pradesh.