Document Title - Geoscience Australia

Lord Howe High Resolution Grids
SATELLITE DERIVED BATHYMETRY DATA
Two sources of satellite derived bathymetric data were available.
Quickbird
In shallow water areas less than about 20 metres deep it is possible to use multi-spectral satellite data
for the determination of water depth. Images from the Quickbird satellite were obtained and
processed to extract bathymetry in areas close to shore. A complete explanation of the processes
involved in obtaining bathymetry from multi-spectral satellite data is given in Appendix 2. The data
distribution is shown in Figure 19.
ETOPO1
In deep water areas, satellite observations of sea height can be processed to determine the
gravitational field over the ocean surface and estimate an underlying bathymetry (Smith and
Sandwell, 1997). The latest release of this bathymetric dataset is known as ETOPO1 which was
mentioned earlier as one of the publicly available grids covering the Lord Howe Island area.
Unfortunately in the Lord Howe Island area ETOPO1 was found to be about 150 metres too shallow
in many places and too deep in others when compared to soundings data. It was decided to only use
subsets of this dataset in the vicinity of two seamounts. This data was obtained from the NGDC and
is shown with other NGDC data as the two squares of data in Figure 17.
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