Investigation of volcanic discoloured water by LANDSAT data.
Since a LANDSAT ground station in Japan was into operation in January 1979, it has become easier to obtain LANDSAT data covering seas around Japan. Consequently, the model areas have been selected in those sea areas adjacent to isolated volcanic islands and submarine volcanoes around Japan, and investigations using LANDSAT data have been attempted for discoloured water caused by volcanic activities in such areas. The LANDSAT data obtained for the eight model areas during the past year or so were, for most images, intercepted by clouds, so that data having high quality images were about 3 percent in number. However, information on the discoloured water was detected from data including that concerning seas around Satuma-Io Sima. Accordingly, as a result of the investigations, it was covering ascertained that information on the volcanic discoloured water could be detected from LANDSAT data. The image data on the film of the LANDSAT data is useful for the analysis of the discoloured water and its qualitative analysis which can be easily conducted with composite images by using the colour viewer system, while use of computer compatible tapes (CCT) is in its minute quantitative analysis. However, there are some problems still unsolved useful in the analysis by CCT, and it is especially important to establish the levels of radiancy among the spectral bands and their normalization, for determination of the characteristics of the volcanic discoloured water. In detecting information on the volcanic discoloured water, it is advisable that the data should be received and processed in the high gain, since the level range of radiancy of seawater is lower and narrower than that of land areas. In addition, data covering thermal infrared spectra are also essential to investigations of this kind. Key words : remote sensing-submarine volcano
| Main Authors: | , , |
|---|---|
| Format: | Journal Contribution biblioteca |
| Language: | Japanese |
| Published: |
1981
|
| Online Access: | http://hdl.handle.net/1834/16241 |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|