Future Earth observation missions for oceanographic applications: Indian perspectives

Significant progress has been achieved in India in demonstrating the utilit y of remote sensing data for various oceanographic applications during the last one decade. Among these, techniques have been developed for retrieval of ocean surface waves, winds, wave forecast model, internal waves, sea sur face temperature and chlorophyll pigments. Encouraged from these results as well as for meeting the specific and increasing data requirements on an as sured basis by oceanographers, India is making concerted efforts for develo ping and launching state-of-the-art indigenous satellites for ocean applica tions in the coming years. The first in the series of ocean satellites planned for launch is Oceansat- 1 (IRS-P4) by early 1999. Oceansat-1 carries on-board an Ocean Colour Monit or (OCM) and a Multi-frequency Scanning Microwave Radiometer (MSMR). OCM wi ll have 8 narrow spectral bands operating in visible and near-infrared band s (402-885 nm)with a spatial resolution of 360 m and swath of 1420 km. The MSMR with its all weather capability is configured to have measurements at 4 frequencies viz., 6.6, 10.65, 18 & 21 GHz in dual polarisation mode with a spatial resolution of 120, 80, 40 & 40 km, respectively with an overall s wath of 1360 km. The Oceansat-1 with repetitivity of once in two days will provide global data for retrieval of various oceanographic and meteorologic al parameters such as chlorophyll (primary productivity), sea surface tempe rature and wind speed, besides a host of other parameters of relevance to m eteorology. A full fledged satellite for ocean applications known as Oceansat-2 (IRS-P7 ) is also planned for launch during 2002. This satellite with payload mix o f microwave (Scatterometer, Altimeter 8 Passive Microwave Radiometer), Ther mal (TIR) and Optical (OCM) sensors, will provide greater in-sight into the global understanding of ocean dynamics/resources. This mission is expected to provide a complete set of oceanographic measurements, which are useful for providing operational oceanographic services. Efforts are also on towards development of missions having multi-frequency, multipolarisation and multi-look angle microwave payloads including Synthe tic Aperture Radar (SAR) and advanced millimeter wave sounders, besides dev elopment of imaging spectrometers by 2005. A well-knit plan has been initiated in India for utilisation of planned Oce ansat data. Important efforts initiated in this direction include SATellite Coastal and Oceanographic Research and Ocean Information Services, which a re being carded out on an integrated basis aiming at providing services to the down stream users. The paper highlights these efforts in India towards providing an operational ocean information services in the coming years. (C ) 1998 International Astronautical Federation Published by Elsevier Science Ltd. All rights reserved.