Remote Sensing activities in India

Remote Sensing activities in India

M G Chandrasekhar, V. Jayaraman, K. Radhakrishnan, B. Manikiam and H Honne Gowda
Indian Space Research Organization
Antariksh Bhawan, New BEL Road

Abstract
In recent time the need for sustainable development of natural resources in consonance with the environment is felt in view of the rapidly increasing population and the impacts of human activities on climate and ecology. Space Remote Sensing is contributing significantly through its capability for periodical and accurate monitoring of the resources. India has made significant progress in operational utilization of Remote Sensing in various resource sectors. The most significant event of the year has been the successful launch and operationalization of IRS-1B satellite. IRS-1A, launched in March 1988, continues to provide Remote Sensing services beyond its expected life of three years. IRS-1B, identical to IRS-1A together provide a repetitivity of 11 days thus enhancing the scope for monitoring dynamic processes associated with natural resources and environment. The receiving station at Hyderabad has been upgraded to receive microwave data from ERS-1 satellite besides data from IRS-1 , Landsat and NOAA. The development programme for the second generation IRS satellites – IRS-1C and IRS-1D scheduled for launch during 1993-94 and 1996-97 respectively is progressing on schedule. These satellites will have better capabilities byway of higher spectral and spatial resolutions, stereo-viewing and on-board recording.

Remote Sensing applications in the country under the umbrella of the National Natural Resources Management System (NNRMS) has achieved operationlization in diverse themes, such as crop acreage/yield estimation, drought assessment, flood management, current agricultural landuse/landcover for agroclimatic zonal planning, wasteland development, water resources management, snow-melt-run-off prediction, fisheries potential, forecasting, coastal zone management, urban development, mineral prospecting and forest resources surveys. Several major projects have been completed with active involvement of the users at central, state and district level so as to ensure effective harnessing of this technology at grass root level. Mapping of ground water potential zones, land use / cover, wastelands, forests and coastal zones have been completed for the entire country. These concreted efforts have led to the development of a National (Natural) resources information system (NRIS) encompassing multidisciplinary themes. As part of the associated modeling efforts, several resource management models have been developed especially in the areas of urban development, wasteland management, mineral targeting and district level planning. Indigenous development of Geographic Information System (GIS) packages has been accomplished to support the NRIS efforts.

The state Remote Sensing application centres continued to provide support for the major national efforts besides taking up projects of direct relevance to the sate. Towards human resources development, several training institutions in the country are offering regular training programmes towards meeting the demand for trained manpower and so far over 4,800 scientists/engineers have been trained in Remote Sensing in the country. The need to strengthen the Remote Sensing components of education in order to cater to the growing demand for trained personnel has been realized and several steps has been initiated.

Specific projects have been initiated on soil moisture, ocean dynamics and monsoon forecasting as per of microwave Remote Sensing programme using data from ERS-1 satellite. An airborne version of C-band Synthetic Aperture Radar (SAR) has been developed and test flights have been conducted.

As a logical sequence to the operationalisation of Remote Sensing applications in various themes and the indigenous capabilities developed for GIS applications, a National Mission on integrated study by land and water resources using Remote Sensing data mainly for generating action plan for sustainable development has been launched in the country. Under this programme 149 districts, representing diverse terrains, agroclimatic zones and social practices have been selected with the objective of arriving at locale specific prescriptions to ensure sustained and environmental friendly development plans. This programme will from a major contribution form India during the International Space Year.

Introduction
Over the past two decades, India has achieved significant progress in space technology and applications for monitoring and management and natural resources. The successful launch and operationalization of IRS-1B and the continued satisfactory functioning of IRS-IA beyond its design life of three years are noteworthy millstones in the Indian Remote Sensing programme. The capability of space technology for obtaining systematic, synoptic, rapid and repetitive coverage on a time and cost effect manner has virtually revolutionized natural resources management and has led towards its use of sustainable development of natural resources in consonance with maintaining the environment. This aspect is gaining momentum in recent times in view of the rapidly increasing population and impacts of human activities on climate and ecology. Several nationwide, Remote Sensing applications projects have been complete during the year under the overall umbrella of National Natural Resources Management system (NNRMS). Rapid advances in computer processing and data handling capability combined with advances in sensor technology have resulted in the realization of progressively increasing spectral and spatial resolutions and in reducing the turn-around-time, crucial in disaster forecast and management.

Space Remote Sensing in India has established beyond doubt its potential and important role in providing vital inputs towards monitoring agricultural crops, forests, water resources, minerals, wastelands, ocean and marine resources, besides aiding drought and flood management. The availability of active microwave Remote Sensing data recently has provided further impetus to the use of Remote Sensing especially in areas such as oceanic studies in view of its additional advantages of all weather capability. The present paper reviews the state of the art of space technology and its applications/activities in the country.

Indian Remote Sensing Programme
The IRS-1A, the first of the operational Indian Remote Sensing Satellites, which was launched on March 17, 1988 is continuing to function satisfactorily, much beyond its design life of 3 years: so far, over 4,50,000 data products have been generated from IRS-1A.

The most significant scientific events of the year is the successful launch of India’s second operational Remote Sensing satellite, IS-1B, on August 29, 1991 from the Baikonur Cosmodrome in the erstwhile USSR. After a series of post launch operations carried out from the Spacedraft Control Centre at Bangalore, IRS-1B was declared operational on September 16, 1991 and the satellite has been providing good quality imageries. IRS-1B payload, identical to those of IRA-1A, consist of two types of advanced imaging sensors –Linear Imaging Self Scanners – LISS-I (Resolution of 72.5m) and each LISS-IIA and LISS-IIB (Resolution of 36.25m(. LISS-I provides a swath of 148 km while the composite swath of the two LISS-II cameras is 145 km. the cameras operate in four spectral bands in the visible and near infrared region of the electromagnetic spectrum in the range of 0.45 to 0.86 micrometers. The cameras make use of linear arrays coupled devices (CCD) as detectors with one CCD array for each spectral bands. A few improvements have been carried out on IRS-1B based on the operational experiences of IRS-1A and this includes time tagged command capability to enable multiple payload operations anywhere in the world. The combined Turn-Around-Time of 11 days is possible with IRS-1A and IRS-1B in orbit.

The second generation IRS satellites, namely IRS-1C and 1D has been designed taking into account the recent technology development scenario and use requirements during the latter part of the nineties. These satellites will have better spectral and spatial resolutions, more frequent revisits, stereo-viewing and onboard recording capabilities. Three improved cameras one operating in panchromatic camera will have off-nadir viewing capability which will help revisiting a place within 5 days. Panchromatic camera provides an imagery of better than 10 meter resolution. one multi spectral camera names LISS-III incorporates middle infrared band in addition to visible and near infrared bands. LISS-III will provide imagery at a resolution of about 23 meters covering a swath of 140km. the middle infrared band will provide imagery at 70 meters resolution cover a swath of 148 km. the third camera, named Wide-Filed Sensor (WIFS) will operate in two visible bands to provide imagery at a resolution of 188 meters covering a swath of 770 km. IRS-1C and 1D are scheduled for launch during 1993-94 and 1996-97 respectively and ensure data continuity beyond the mid 90’s.

In the area of microwave Remote Sensing, based on the experience gained from development and operationalization of a Side Looking Air-Borne Radar (SLAR), an air-borne Synthetic Aperture Radar (SAR) has been developed and test fightings conducted successfully.

As a follow-on to the second generation IRS-1C and 1D satellites, it is planned to embark upon appropriate Remote Sensing platforms which would carry payload with better spatial resolution and operating in narrow optical spectral bands. In addition active and passive microwave sensors are also planned for the Missions to ensure availability of integrated Remote Sensing databases, vital for an all-round development of the country.

Data Reception, Processing and Dissemination
The NRSA Data reception station at Shadnagar near Hyderabad with capability to receive data from the IRS-1A, IRS-1B, Landsat, ERS-1 & NOAA satellites provides a wide choice of Remote Sensing data to the Indian users with reduced turn-around-times. The facilities are designed to generate, on an operational basis, photographic and digital, data products at various levels/formats meeting the throughout and turn-around-time requirements of the users.

An integrated Information Management System (IIMS) has been developed to efficiently manage the large volume of information on data acquisition, archival, processing and dissemination and to optimize the utilization of the expanding data processing capability at National Remote Sensing Agency (NRSA). NRSA data Center supplied about 15,500 data products during the year with about 75% covering from IRS-1A/1B. Work on the augmentation of data reception station for acquiring higher resolution data from IRs-1C and IRS-1D satellites has been initiated.

Remote Sensing Applications for National Development
The Indian Space Programme has made great strides in using the sophisticated Remote Sensing technology in a timely and cost-effective manner to maximally benefit the grass-root level of the nation. Even with the relatively modest investment made. So far, the nation has established is now playing a crucial role in the management of natural resources.

Several areas of applications have been operationlised with the active involvement of use departments / agencies thus ensuring effective harnessing of this modern technology solving locale specific problems of relevance to the country.

Major highlights of the achievements in different resource sectors are as follows :

Landuse/land cover mapping on 1:250,000 scale have been prepared for the whole country using IRS-1 multi data to help in the preparation of operational plans for 15 agroclimatic zones of India through adaptation of cropping patterns, fallow lands, grazing lands, wastelands and surface water bodies.
Low resolution satellite data is providing advance information, at tehsil/district level, on the extent and severity of agricultural drought conditions and fortnightly drought assessment bulletins are being issued for 240 odd drought prone districts in the country. Efforts are on to integrate meteorological data and information on surface/ground water availability to further improve the usefulness of the drought forecasts.
Identification of crops, acreage estimation and forecasting their yield have been operatinalzied for all major corps such as wheat, rive, sorghum, Cotton, groundnut, tobacco, tea etc. Remote Sensing based preharvest acreage estimates for cops have become an integral part of the agricultural management in the country. Efforts are on to extend the methodology to mixed crop regions of the country, horticulture and agricultural plantations.
Satellites Remote Sensing data is being successfully used for obtaining real time information on area affected by major floods towards assisting rehabilitation measures. Quantitative estimation of the flood damage to infrastructure and agricultural crops is also being provided.
Wasteland maps giving information on type and extend of wastelands at village level are being used in conjunction with geographical information system to generate comprehensive plans for reclamation of wastelands.
Space Remote Sensing has been very effectively used in India for identifying prospective ground water potential zones for suitable exploitation with reduced time and efforts. The hydrogeomorphological maps generated for satellite data have been effectively put to use for locating sites for over 2 lakhs borewells with high success rats of 85 – 92%.
Satellite data is contributing significantly for the forest management through biennial forest cover mapping and use of these maps for maintaining of ecological balance in critical areas.
In the are of water resources management, Remote Sensing data is being used for prioritization of watersheds, surface water monitoring, rainfall run-off studies, snowmelt runoff forecasting and irrigation scheduling.
Digital analysis of mulitdate date has been used to prepare urban sprawl maps of major cities in the country with over 1 million population, as a baseline information for perspective planning of their growth. Geographical information system is being utilized for analyzing the multi-parameter data for providing guidelines to city planners to solve urban related problems.
Study of the entire coastal line of the country for tidal wetlands, coastal landforms, potential aquacultures sites, mangroves, estuarine dynamics/shoreline changes, and off-shore aspects like suspended sediment dynamics and coastal currents, near shore bathymetry, internal waves has been made.
Preliminary maps on coral reefs h been completed details of coral reef extent and related environmental aspects.
A national programme on ocean Remote Sensing programme is I progress focusing (i) Sea Surface Temperature (SST) retrieval and applications, (ii) microwave applications, (iii) setting up of a national ocean information system and (iv) ocean modeling.
Fisheries prospects charts based on location of thermal fronts derived from sea surface temperature charts are being generated from all Maritime States. The feedback from the users has indicated improved fish catch in notified areas.

Integrated Studies for Sustainable Development
A unique approach has been evolved to use satellite Remote Sensing data, suitably integrated with socio-economic and meteorological information, to arrive at developmental plans that will ensure sustainable development of natural resources at microlevel. The developmental plans so arrived at are also ecologically balanced and environmental friendly. Locale specific solutions / prescriptions are arrived at through the use of an integrated data base created using Geographical Information System and follow-up scientific discussions with the resource experts and planners in the region.

The methodology (fig. 1) involves generation of thematic maps showing current land use/ cover, type of wastelands, forest cover / types, surface water resources, drainage pattern, ground water potential zones, geomorphology (landforms), geology (rock types, structural details, mineral occurrence), soil types etc., derived using satellite data. While the slope map is prepared using the topographic contour information and meteorological data (rainfall intensity and distribution) collected from existing data bases. Based on these data, maps showing land capability, land irrigability, soil erosion status, run-off potential, priority watersheds, etc are prepared. While existing information on the area is used as collateral data base validation of the above maps through selective field check is also an integral part of the exercise.

Figure 1. Integration of resources data with socio-economic & meteorological information - schematic
The socio-economic, socio-cultural and demographic information is taken from the available data bases and through specific surveys as required all the above maps and information are integrated, through use of go Geographic Information systems. The priority watersheds/blocks demarcated based on their degradation status are further subdivided into a number of microlevel spatial units which are unique in terms of their resource potential and constraints. To give an example, a typical microlevel spatial unit may have identical status on soil limitations, terrain characteristics, erosion status, salinity/alkanity, moisture holding capacity, rainfall distribution, water resources potential etc specific action plans are formulated for such spatial units to ensure optimum management of land and water resources. While doing, so the cultural acceptability and environmental compatibility of the recommended practices is ensured (Fig. 2).

Figure 2. Action plan for sustainable development (part of Bhiwani district)
Under the integrated approach for sustainable development, Department of Space had initiated pilot studies for 21 districts in India during 1990, representing diverse terrains, agro-climatic zones and social and cultural practices. Based on the encouraging results obtained from the pilot scale studies, a major programme covering 149 drought prone and problem districts of the country (covering nearly 45% of India’s geographical area has been initiated.

New areas of applications

Monitoring of volcanic activity in Barren Islands
Study on volcanic eruption in Barren Islands of Anadaman & Nicrobar Archipelago during March 1991 using IRS-1 data has indicated that the eruption started around Mach 25, 1991 and the pre-eruption warming took place even earlier. The smoke plumes during the eruption and the volcanic vent with high temperature (around 11000C) are very clear on the satellite data.

Geosphere-Biosphere Studies
Considering the importance of global climatic changes and its impact on natural resources, Department of space has initiated a programme on Geosphere-Biosphere studies. This programme utilizes the inputs available from archived satellite data and data from upper atmosphere studies carried out under Indian Middle Atmospheric Programme (IMAP). The projects initiate under the programme are:

Cloud-radiation interaction
Ocean productivity and carbon cycling.
Impact of Biosphere on climate.
Surface hydrology modeling
Cryosampler development for upper air measurements of minor constituents.
Baseline monitoring of Ozone/CH4/CO
Development of instrumentation for CO2/NOx monitoring
Atmospheric boundary layer experiments
Biomass and net primary productivity estimation.

Microwave Applications
Considering the future India’s programme on microwave & the present availability of ERS-1 data, a set of application projects have been initiated in the areas of soil moisture estimation; geomorphological mapping, estimation of SST and cloud height; wave action modeling in the coastal and offshore regions; oceanic eddies and internal waves; bathymetric analysis and heat budget study of the equatorial Indian Ocean.

National (Natural) Resources Information System (NRIS)
A configuration for the National (Natural) Resource Information System for the country considering all sectors and their hierarchy levels (District/State/Regional/National) has been prepared. Pilot projects initiated under the NRIS in the themes of urban and regional information systems, wastelands development system, watershed management, regional mineral targeting and district level planning have made significant progress. As part of modeling efforts, several resources models have been developed. Development of indigenous Geographic information system (GIS) packages has been accomplished to support the NRIS efforts.

Infrastructure Development
The five operational Regional Remote Sensing Service Centres (RRSSCs) at Bangalore, Dehradun, Jodhpur, Kharagpur and Nagpur are actively supporting the execution of various national level projects, user projects, application validation projects and software development activities. Twenty-one states have set up Remote Sensing Application Centres equipped with interpretation facilities towards harnessing the Remote Sensing potentials for natural resource management. Most of the States are in the Process of upgrading the facilities by adding digital image processing systems. The State centres continued to provide support for major national efforts besides taking up projects of direct relevance to the States.

Remote Sensing Training and Education
Increased awareness of the role of space Remote Sensing and its application potential has resulted in increased demand for trained manpower in the country. The existing training institutes, viz., Indian institute of Remote Sensing (IIRS) – Dehradun, Centre for studies in Resource Engineering (CSRE-IIT), Bombay, Institute of Remote Sensing – Anna University (IRS-AU), Madras, Geological Survey of India Training Institute (GSI-TI), Hyderabad, National Bureau of Soil Survey and Landuse Planning (NBSS& LUP), Nagpur, forest Survey of India (FSI), Dehradun, National Remote Sensing Agency (NRSA), Hyderabad and regional Remote Sensing Service Centres (RRSSCs) etc., continued to provide training programmes for user scientists. So far, about 4800 scientists / engineers have been trained in Remote Sensing in the country. Specific efforts are on for introduction of Remote Sensing at upper secondary school and post-graduate levels.

Information Dissemination and User Interaction
Towards apprising the user community on the recent developments in space technology and Remote Sensing applications, several user meetings and discussions have been conducted. Also, several technical reports/publications/application notes have been brought out. Among them few important publications are NNRMS bulletins from NNRMS Secretariat, Bangalore, Interface from NRSA, Hyderabad and IRS News Letter from Space Applications, Centre, Ahmedabad.

International Cooperation
As part of the International Cooperation, India continued to provide support to the cause of developing countries establishing viable Remote Sensing programmes. India as the Current Chairman of the Intergovernmental Consultative Committee of Regional Remote Sensing Programme ESCAP/UNDP, hosted the meeting of the Directors of National Programme of member countries during September 1991 at Hyderabad. The discussions during the meeting led to further focusing of efforts in the region for use of Remote Sensing and geographical information system for Sustainable development of natural resources. Under the SHARES programme, India continued to provide training support to scientists from developing countries.

Conclusions
With the launching and operationalisation of IRS-1A and 1B and backed by appropriate ground segments, Indian Remote Sensing programme has emerged as a viable, self-reliant and operational system contributing for the national development. The second generation satellites IRS-1C/1D will provide continued and assured space Remote Sensing services to the user community in the country. Remote Sensing based integrated studies for sustainable development of natural resources is of great significant and Indian experiences in this regard has been quire encouraging. Geographic Information System and development of Natural Resources Information System (NRIS) should provide appropriate action to be taken I the coming decades for sustainable developing within the carrying capacity of our resources. Satellite Remote Sensing by virtue of its capabilities to generate resource information at various scales in a cost effective manner will benefit in the long run development and monitor factors contributing to necessary infrastructure and trained manpower availability have been established for the development of a country.

Acknowledgment
The authors acknowledges the valuable inputs provided by the NNRMS user community. The authors also thank Ms. S. Vanaja for neat typing of the manuscript.

References

U.R.Rao, Remote Sensing for National Development, Current Science, Vol. 61, Aug. 1991, p. 121-128.
K. Kasturirangan, et al., IRS Mission Current Sceince, Vol. 61, Aug. 1991, p. 136-152.
M.G. Chandrasekhar, et al., Remote Sensing Activities in India, ACRS Kaulalumpur, Sept. 1991.