Create Bathymetry Map in Matlab from xyz Data

Matlab is a high-level computing language. There are many purpose using this program. In this post, I will describe how to make bathymetry map from xyz data in Matlab. Main idea of the process is only make x data, y data and z data to be a grid because of use surf command, so simple.

OK lets start .....

Before make a Matlab script, you must have xyz data, as an example I use data from  ETOPO 1 National Geophysical Data Center (NGDC) NOAA, you can download here. Select your area of interest and choose xyz data as an output format.

Steps in Matlab :

• Load your xyz data.
• x data is longitude, y data is latitude and z data is depth.
• Use unique command for x data and y data.

lon = unique(yourdata(:,1));
lat = unique(yourdata(:,2));

• Make a grid from lon and lat data

[LAT LON]=meshgrid(lat,lon);

• Make z data as a grid using this command.

for n=1:length(yourdata)
   ilon = find(lon==yourdata(n,1));
   ilat = find(lat==yourdata(n,2));
   depth(ilon,ilat) = yourdata(n,3);
end

• Use surf command.

surf(LON,LAT,depth);
shading interp;

• Run your matlab script.

This is example of resulting display

Bathymetry Map of England

Bathymetry Map of Indonesia

Bathymetry Map of Japan