tailieunhanh - Báo cáo " Bathymetry Mapping from Satellite Images for Ly Son Island, Quang Ngai Province "

Up to present, in Vietnam, the traditional methods used to map marine bathymetry are still very popular. These techniques have advantages of giving a high accuracy but still show big disadvantages of taking too much time for the data acquisition and processing and of being very expensive for the field works. Compensated to these cons the remote sensing technique seems to be an ideal solution since the images covers almost places on the earth with very high frequency (hours) of acquisition and served with a reasonable price even some of them can be downloaded from the internet for. | vnu journal of science earth sciences n0i 2007 bathymetry mapping from satellite images for ly son island quang ngai province Le Nhu Nga Nguyen Thi Kim Nga Institute of Mechanics ABSTRACT. Up to present in Vietnam the traditional methods used to map marine bathymetry are still very popular. These techniques have advantages of giving a high accuracy but still show big disadvantages of taking too much time for the data acquisition and processing and of being very expensive for the field works. Compensated to these cons the remote sensing technique seems to be an ideal solution since the images covers almost places on the earth with very high frequency hours of acquisition and served with a reasonable price even some of them can be downloaded from the internet for free of charge. In this paper LANDSAT-7 ETM optical-multispectral image a space-born sensor of Ly Son Island area Quang Ngai Province where the water is relatively clear was used some state-of-the-art methods of bathymetry mapping from optical-multispectral satellite images were reviewed and tested the data from marine chart was used for the model calibration and quality assessment and the discussion on the potential of these data sources for mapping coastal areas of Vietnam was also conducted. 1. Introduction The bathymetry is a branch of the oceanography that deals with the measurement of the depths of the sea and studies its configuration and evolution over time. It is an important data for activities on marine and coastal areas such as engineering navigation researches management and for hydro-dynamical applications as input data. In Vietnam the echo-sounding technique with sonar equipment mounted on a ship or boat has been being applied mostly for the bathymetry mapping Dang 1998 . In the world the remote sensing technique has been being used for decades IfM HH. 2005 Green et al. 2000 from different sensors such as optical RADAR and LIDAR. RADAR was used for global and regional scale while .