Application of Oceansat-1 MSMR analysed winds to marine navigation

Abstract

The launch of the Indian Remote Sensing Satellite IRS-P4 (Oceansat-1) has opened up many important applications. Meteorological navigation is one of the new avenues, which was suffering due to the lack of a synoptic wave database. The research in this area was hindered mainly by the unavailability of real-time wind data. Now, it has become feasible to carry out routine wave forecasting. The Multi-frequency Scanning Microwave Radiometer (MSMR) channel of the satellite gives scalar wind information. This is analysed at the National Center for Medium-range Weather Forecast (NCMWF), India and converted to vector wind information. The 6-hourly u- and v-components of wind in a 1.5° grid covering both the north and south Indian Ocean are available to the research community for further application. In the present study the information has been used to force a third generation spectral wave model (WAM). The simulations are performed for the rough weather month of July 1999 for the regional grid system of the Indian Ocean. This simulated wave climate formed the basis for computing effective ship velocity in the irregular seaway. This study gives a quantitative estimation of change in ship velocity in the open Indian Ocean for a tanker. The optimal path is charted using Dijkstra's algorithm for the optimum route voyage from Calcutta to Singapore and vice versa.

Acknowledgments

This work is an extension of the Ph.D thesis of Dr J. K. Panigrahi, under the faculty of Marine Science, Berhampur University, India. The input data used are from the Space Application Center and the National Center for Medium Range Weather Forecasting, India. The WAM model is implemented by the authors assimilating IRS-P4 analysed wind fields at the Naval Physical & Oceanographic Laboratory, India under the guidance of Dr J. Swain. The authors are grateful to the Director, NPOL, Director, SAC and Director, NCMRWF, for availing these data during IRS-P4 utilization program.