Immediately after the bouquets for what appeared to be a textbook launch of the indigenous Polar Satellite Launch Vehicle (PSLV-CI), ISRO was pelted with brickbats. The PSLV launch was not been as perfect as it seemed. The liquid engine in the fourth stage of the launch vehicle had under-performed for just 25 seconds in its total 435 seconds of firing. But the drop in the drop in the thrust was enough to put IRS-1D – the indigenous remote sensing satellite that it carried – in an elliptical orbit around the poles rather than a circular one. ISRO’s rocket scientists did succeed in raising IRS-1D to its planned orbit. It is performing well and the quality of pictures is superb. Indeed, ISRO scientists feel that, in spite of the fuel consumed in the orbit-raising operations have proven the robustness of the basic design of the IRS satellite and its subsystem.
The IRS-1D satellite is similar to the IRS-1C launched on December 28, 1995. The IRS-1D will also be providing, as its predecessor IRS-1C, pictures with a resolution of 5.8 m, the highest available in the world.
Indian has a very good potential for marketing our remote sensing data, since we have the largest constellation of remote sensing satellites in operation. Polar orbiting satellites, IRS-1A, IRS-1B, IRS-P2, P3 and 1C have highlighted India’s capability in this area of spacecraft technology. India’s achievements in the application of space based remote sensing technology have won international recognition. These satellite provide multispectral imageries with varying resolutions ranging from 180 m to 23 m and a shorter repetitively cycle (taken together), for vital information on forests, environment, agricultural crops, soil conditions, wasteland identification, flood and drought monitoring, ocean resource development, mineral exploration, land use and monitoring of underground and surface water resources, to the entire nation on a continuing basis.
Antrix, the marketing arm or ISRO has teamed up with Earth Observation Satellite Company EOSAT of the U.S. (now known as Space Imagining – EOSAT) for the distribution and marketing of data from IRS constellation of satellites for use of the international remote sensing community. The firt ground station outside India to start receiving IRS data has been the one in Norman, Oklahoma (U.S.), which has been doing so since mid 1994. With the capability to receive and process IRS-1C data recently established, this station has been able to cater to the entire North American market. The Germen station at Neustrelitz, Berlin, is also receiving IRS data since min-1996. The Thailand station in Bangkok has also been equipped to receive and process IRS-1C data since May 1997. Another station in Japan has also come up recently which is receiving this data. More ground stations are expected to be part of the IRS network soon. Antrix and SI-E will also cooperate in the field of providing information on data products and value added services.
ISRO has a commercial contract to launch a Korean satellite alongwith the IRS-P4 satellite, when will be launched next year.
Space Programmes: Past, Present and Future
Indian remote Sensing Satellite System (IRSS)
Indian Remote Sensing Satellite (IRS) system was established with the launch of IRS-1A in March 1998. The IRS system, at present, has four ISRO-built satellites, IRS-1B launched in August 1991, IRS-1C launched in December 1995, IRS-P2 launched in October 1994 and IRS-P3 were launched by India’s Polar Satellite Launch Vehicle, PSLV, during its second and third development launches.
IRS-1A
IRS-1A, carries two types of cameras, LISS-I and LISS-II with spatial resolution of 72.5 m and 36.25 m, respectively. LISS-I has a swath of 148 km and the two LISS-II cameras have a composite swath of 145 km.
IRS-1B
IRS-1B is like its predecessor IRS-1A. The satellite continues to perform well in orbit.
IRS-1C
IRS-1C has enhanced capabilities in terms of spatial resolution, additional spectral bands, stereoscopic imaging, wide field coverage and a more frequent revisit capability than its predecessors. It caries a tap-recorder on board for recording the data when data is not being transmitted in real time. IRS-1C has three cameras on board.
Panchromatic camera (PAN) which has a spatial resolution of 5.8 m, operates in Panchromatic region of the Electro-magnetic spectrum, with a swath of 70 km and can be steered up to 26 degrees across track thus enabling generation of stereoscopic imagery and improved revisit capability
Linear Imaging Self Scanner – III (LISS-III) camera operating n four spectral bands three in Visible/Near Infrared (VNIR) and one in Short Wave Infrared (SWIR) region. It has a spatial resolution of 23.5 m in VNIR bands and 70 m in SWIR band and a swath of 142 km and 148 km, respectively.
Wide Field Sensor (WiFS), a coarse resolution camera with spatial resolution of 188.3 m and covering a wide swath of 810 km with 2 spectral bands in visible and NIR region.
IRS-P2
IRS-P2 has LISS-II cameras similar to those of IRS-1A and IRS-1B, but with improved resolution of 32 m and a swath of 148 km.
IRS-P3
IRS-P3 caries two remote sensing payloads for applications related to oceanography and vegetation dynamics, as follows:
A Wide Fild Sensor (WiFS), similar to that of IRS-1C but with an additional Short Wave IR (SWIR) band for the study of vegetation dynamics.
A Modular Opto-electronic Scanner (MOS), designed and developed by DLR, Germany, and 18 channel imaging spectrometer in visible / near-IR region providing an effective ground resolution f 500 m X 500 m and a swath of around 200 km. MOS payload is optimised for oceanographic applications.
Besides, IRS-P3 also carries an X-ray Astronomy Payload to study the time variability and spectral characteristics of cosmic X-ray sources and for detection of transient X-ray sources.
IRS-1D
IRS-1D, similar to IRS-1C, was launched on 29th September 1997 on PSLV-C1
IRS-P4
IRS-P4 is planned for launch on-board PSLV-C2 during 1998-99. It will have payloads specifically tailored for measurement of physical and biological oceanography parameters; an Ocean Colour Monitor (OCM) and a Multi-frequency Scanning Microwave Radiometer (MSMR) – both for oceanographic application. Additionally, a Satellite Positioning System (SPS) is also being planned to be incorporated.
OCM is a solid state camera operating in push broom scanning mode, using a linear array Charge Coupled Devices (CCD) for generating ocean biological parameters. The camera provides a resolution of 360m covering a swath of 1,420 km. The camera operates is 8 VNIR bands.
MSMR, with its all weather capability will be useful for measuring sea surface temperature and meteorological parameters like atmospheric water vapour and sea surface winds. The MSMR is configured to have measurements in four channels at a constant incident angle of 50 degrees with an overall swath of 1,380 km. Satellite Positioning System (SPS) has been included as a part of main frame to provide a location accuracy of 50m.
IRS-P5
IRS-P5 is intended for cartographic application with two panchromatic cameras providing better than 2.5 m resolution with steerable swath of 30 km. The cameras provide stereo pairs of images needed for the generation of Digital Terrain Model (DTM) / Digital Elevation Models (DEM). The satellite will provide cadastrsal level information up to 1:50,000 scale for thematic applications. IRS-P5 is planned to be launched by PSL-C3 during 1999-2000.
IRS-P6
IRS-P6 is planned to carry multispectral camera LISS-III, similar to that of IRS-1C/1D providing 23m spatial resolution in all four bands and LISS-IV , a high resolution multispectral camera, providing better than 6m resolution working in green , red and near infrared bands. An Advanced Wide Field Sensor (AWiFS) camera with a spatial resolution of around 80-100 m in three spectral bands and a swath of around 800 km is also planned to be included. IRS-P6 will be useful for resource applications in newer areas like vegetation and multi-crop discrimination, species level discrimination , etc. It will help in microlevel decisions for resources management as well as in providing continuity of services of IRS-1C / 1D systems. IRS-P6 is planned to be launched by PSLV during 2000-2001.
| Satellite | Country | Resolution |
| Landsat 5 | US | 30m multispectral |
| SPOT 1 & 2 | France | 10m panchromatic, 20m multispectral |
| JERS-1 | Japan | 18m multispectral, extended infrared capability |
| IRS 1C / 1D | India | 6m panchromatic, 18m multispectral |
| COSMOS | Russia | 2m / 10m photo-digitised |
| Radarsat | Canada | dynamic energy system, variable resolutions from 8m to 100m |
Programmes of other countries
(Extracted from the Prof. Pisharoty Lecture Series – Inauagural Lecture delivered by George Joseph, Space Application Centre on February 23, 1996 at Space Application Centre, Ahmedabad and organised by Ahmedabad Chapter of ISRS)
NASA
One of the important international mission is Mission to Planet Earth of NASA, USA. The important component of this mission is the Earth Observation System (EOS). Under EOS a series of satellites are planned, carrying a variety of playloads to cover different components viz., land, ocean and atmosphere. Two of the payloads are described here. The Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) is an interesting payload for producing multispectral imagery from the visible to thermal infrared range. It has three bands with 15 m resolution, in the 0.5 t 0.9 m range and six bands with 30 m resolution in the 1.6 and 2.5 m Range and 5 thermal infrared channel between 8 and 10 m range with 90 m resolution. One of the VNIR bands will provide along track stereo view with a base to height ratio of 0.6. The instruments for land and ocean application of interest is Moderate Resolution Imaging Spectrometer (MODIS). MODIS has 36 discrete bands between 0.4 and 14.4 m with spatial resolution varying from 250 m to 1 km.
Japan
The Japanese future Remote Sensing Satellite Programme include the ADEOS-I and II which carry sensors for the ocean, land and atmospheric studies. One of the most advanced sensors beyond 2000 will be Japan’s Advanced Land Observing System (ALOS) which has 10 m multispectral and a Panchromatic camera with force and aft capability with 2.5 m resolution.
European Space Agency (ESA)
ERS-1 and 2 carrying microwave sensors (specially SAR) is an important contribution to the remote sensing community by European Space Agency (ESA). Future ESA Remote Sensing Missions will have two types of satellites, ENVISAT which books at the environment and METOP for meteorological observation. METOP will provide continuity to the operational meteorological satellite services. The future French satellites SPOT-4 proposed to be launched in 1997 will have an additional spectral band in the range 1.55 to 1.7 m compare to SPOT 5 which is planned around 2005 may have 10 m multispectral capability and PAN camera with 5 m that are being talked about. One of the system, Eye-glass, is expected to produce resolution.
There are a number of high resolution imaging systems imagery with 1 m resolution. However, such systems have only very small swath (10 to 15 km) and can be used only for sampling earth surface without giving data on a continuos basis and assured temporal resolution.
Publication
INDIA IN ORBIT: Mohan Sundara Rajan,
Publication Division, Ministry of Information and Broadcasting,
Government of India, Patiala House,New Delhi-110001 Rs. 70
Mohan Sundara Rajan, in his book with the appropriate title “India in Orbit” has documented India’s space efforts spread over a period of 30 years.
There are seven colour plates of which two – one on the vegetation index map of India compiled from the Data given by coastal region of Vishakapatnam – are outstanding.
The book has a foreword from the eminent nuclear physicist, Dr. Raja Ramanna, who has congratulated the author on “writing a highly readable narrative which – will be useful to all those who wish to be better informed about the country’s space technology and its application.” Coming from some one of Dr. Ramanna’s stature, that is an eloquent testimony to the merit of the book.
| Name of the Satellite | Resolution (panchromatic) | Resolution (multispectral) | Expected year of launch |
| Earth Watch Early Bird |
3 m | 15 m | 1997 end |
| Space Imaging IKONSOS |
1 m | 4 m | 1997 end |
| Earth Watch | .82 m | 3.28 m | 1998 end |
| OrbImage Orbview3 | 1 m | 4 m | ~ 1999 |
| Israeli Aircraft/Core Software |
1.8 m | ~ 1999 | |
| Boeing Resource 21 | 1 m | 10 m | ~ 1999 |
| Aerospatiale Helios2 | 1 m | ~ 1999 |
The Earth Watch Programme
Earth Watch Incorporated is launching a constellation of high-resolution commercial imaging satellites and creating the Digital Globe product database. The first satellites in this constellation, EarlyBird I, will be launched in 1997 and provide 3-meter panchromatic and 15 metre multispectral imagery. The QuickBird I 0.82-meter panchromatic and 3.28 multispectral imaging satellite will be launched in 1998.
Earth Watch will have a constellation of four satellites in orbit, providing frequent revisits on an average once per day, and acquiring imagery at different times of the day to facilitate the acquisition of cloud-free data in the tropics. The in-track acquisition of stereo imagery enables the rapid production of accurate image maps including Digital Elevation Models and 3D imagery for mapping.
The Earth Watch Digital Globe database is the first global geographic information database of the planet incorporating digital imagery acquired by satellites and airborne sensors, digital elevation models, map products, and other geographic data. On-line access to the Digital Globe archives via the Internet will provide customers with a direct-to-desktop connection to Earth Watch products. The Digital Globe database comprises a variety of geographic data archives in addition to the imagery from the Earth Watch satellite systems. This database will be regularly updated to provide complete high-resolution global coverage with on-line availability, at an affordable cost.
The Digital Globe database and world-wide distribution network serves the geographic information needs of global customers in areas such as forestry, land development, environmental monitoring and land management, oil and gas exploration, tansportation, agribusiness and defence. For more information contact:[email protected]; https://www.digitlglobe.com
| Date | Spacecraft | Nature of failure |
| Dec ‘94 | Ariane-42P | Failed launch |
| Jan ‘95 | Long March-2E (Chinese launcher) |
Launch vehicle exploded 50 sees after lit-off |
| Mar ‘95 | START (Russian 5-stage launcher) |
Failed launch |
| Feb ‘96 | Long March-2E (Chinese) |
Vehicle veered 25 sees after lift-off and crashed |
| Feb ‘96 | Proton (Russian workhorse) |
Delivered the Russian RADUGA satellite in a useless elliptical orbit |
| Mar ‘97 | Anik-E1 | Power failure |
| Jan ‘97 | Telstar-401 | Complete failure of telemetry and telecommand systems |
| Jun ‘97 | ADEOS-1 Japanese |
Solar array collapsed in orbit |
| Jul ‘97 | GOES-10 (Loral Aerospace) |
Lost ability to keep solar array positioned towards the sun |
| Sep ‘97 | Intelsat-605 | Began sending incomplete telemetry |
