MARINE SATELLITE INFORMATION SERVICE

A satellite platform with its synoptic view and capability to provide spatially continuous data on a repetitive basis is ideal for the study of oceans. Realising the vast potential of satellite remote sensing techniques, the Department of Ocean Development is implementing a project entitled `Marine Satellite Information Service' (MARSIS), since 1990. The major thrust of the project is to develop society-related data products, either directly relevant for use by the coastal communities or for use in the planning and developmental activities of the coastal zone, apart from scientific research.

INSTITUTIONAL ARRANGEMENT

The infrastructure and the expertise available at a number of national institutes and laboratories under other departments of the Government of India have been beneficially used for implementing the project. The National Remote Sensing Agency (NRSA) at Hyderabad under the Department of Space is the Central Coordinating Agency. The National Institute of Oceanography (NIO), Goa, the Space Application Centre of Department of Space (SAC) at Ahmedabad, the Central Marine Fisheries Research Institute (CMFRI) of the Indian Council of Agriculture Research of Cochin, the Centre for Mathematical Modelling and Computer Simulation (C-MMACS) of the National Aerospace Laboratory, Bangalore, under the Council of Scientific & Industrial Research, the Insitute of Ocean Management (IOM), Anna University, Madras, and the Orissa State Remote Sensing Application Centre (ORSAC), Bhubaneswar, are the major collaborating institutes.

STRUCTURE OF MARSIS

The MARSIS programme consists of the following four major projects :
Application of ocean related remote sensing. Sea Truth Collection. MARSIS Centres. Ocean Modelling. Under the first project, data products are generated at NRSA, Hyderabad. Data and imageries from NOAA (National Ocean & Atmospheric Administration), IRS, INSAT, LANDSAT, GEOSAT, ERS satellites are used for generation of data products. Drifting and moored buoys are deployed by NIO, Goa for collection of sea truth data on Sea Surface Temperature, salinity, wind speed, etc. The five MARSIS centres at NRSA, NIO, CMFRI, IOM, ORSAC undertake dissemination of data products and user interaction campaign. The MARSIS Centres are also developing information systems for the management of the coastal zone. All the data generated under the project will be used to develop mathematical models for prediction of waves, winds marine productivity, etc.

MARSIS PRODUCTS

The data products generated under MARSIS are briefly described below:

Sea Surface Temperature

Sea Surface Temperature (SST) is retrieved from the NOAA Satellite on a daily basis and weekly averaged SST charts on 15' x 15' and 1deg.x 1deg. grid are produced. The data product is used for weather prediction and for meteorological research. The SST is also very advantageously used for the delineation of Potential Fishing Zone in the Indian seas. The Sea Surface Temperature derived from the Satellite is duly validated by the sea truth data.

Fishing Zone Potential Information

Based on the weekly averaged SST, thermal gradients are identified and marked on the SST chart. Fish is expected to congregate in the thermal front areas and those areas are delineated as Potential Fishing Zone (PFZ). The information on PFZ is now disseminated to more than 100 fishing centres located along the Indian coast twice a week, that is, on Mondays and Thursdays. Information is going via fax, telex, radio, TV. Daily newspapers are also used for dissemination of the information. The information communicated contains the distance of the PFZ from a known coastal point, bearing and the depth of water at the zone. Adequate training is imparted to the fishermen in the utilisation of the information including the guidance for reaching the PFZ location in the sea.

The information is reaching the coastal zone since three years. The feedback obtained from the Fishing Centres has indicated that the catch in the PFZ area is substantially higher compared to the other areas. Typical histograms showing the catch per unit effort in PFZ areas are given below.

Wetland Maps

Coastal wetland and shore line change maps have been produced covering two of the maritime States of India, that is, Tamil Nadu and Kerala. These maps show particularly the locations of lagoons, backwaters, estuaries, mud flats, etc. They are useful for planning of aquaculture and such wetland based projects. The maps are prepared in the scale 1:50,000.

Coral Reef Maps

Coral reefs are present in the areas of Gulf of Kachch, Gulf of Mannar, Andaman & Nicobar and Lakshadeep Islands. Using satellite imageries, maps for all coral reef areas are produced in 1:50,000. These maps indicate the condition of corals, density, etc and will be useful for monitoring the coral eco-system. It is proposed to bring out such maps at periodical frequency for comparing the conditions and the extent of the corals and for taking appropriate action to protect the coral eco-system.

COASTAL ZONE INFORMATION SYSTEM

The Coastal Zone in India assumes greater importance because of its high productivity, delicate eco-system and extensive and growing use of these areas for socio-economic development. Availability of proper data for the preservation, conservation and management of the coastal zone is hence very critical. Coastal zone information system is developed as a tool to assemble, analyse, store, utilise, retrieve and manipulate the data for the purpose of coastal zone management. A pilot project of the development of coastal zone information system (CZIS) was taken up and completed for the Rameshwaram Taluk, Tamil Nadu State on the east coast of India by application of computer techniques.

These maps provide a set of benchmarks and reference conditions, usually called baseline data, in the coastal areas to monitor longterm trends of the dynamics of the coastal system. Work is now on to develop the information system for the entire Indian coast.