パソコンシステムによる海域画像データの解析

抄録

NOAA AVHRR images of the Kuroshio off Honshuu were analyzed by a personal computer system. After the introduction of the system configuration, the method of estimating surface current velocities of the Kuroshio based on a single NOAA AVHRR image was developed and verified by the shipacquired surface current velocities during the period from 1986 to 1987. Although influenced seasonally and spatially, the method demonstrated the fairly good agreement between the estimated and the observed current velocities along the northern edge of the Kuroshio within the rms errors of about 0.5 knot for the maximum current speed of 3 to 4 knots and of about 14 degrees in current direction. Aiming for the integration of satellite remote sensing with geographic -information system, we also presented the integrated analysis of the AVHRR image with sea surface topography expressed as the geopotential anomaly data. By analyzing three dimensional data, that is, the sea surface temperature as two dimensions plus the sea surface topography as one dimension, we made it clear that the region of the highest temperature gradient corresponded well with the region of the highest surface gradient along the northern edge of the Kuroshio. In average off Toukai, one degree temperature difference equals about one geopotential anomaly difference, which turns out to be about 0.4 knot of geostrophic velocity. In order to strengthen both technologies of satellite remote sensing and geographic information system, more integration will be needed.