Page 163 - MATLAB Recipes for Earth Sciences

158 7 Spatial Data

colormap(flipud(gray.^4))
axis equal, view(0,90)
colorbar

This script opens a new figure window, generates the gray surface using
interpolated shading in an overhead view (Fig. 7.3).

7.5 The Shuttle Radar Topography Mission SRTM

The Shuttle Radar Topography Mission (SRTM) incorporates a radar
system that flew onboard the Space Shuttle Endeavour during an 11-day

mission in February 2000. SRTM is an international project spearheaded
by the National Geospatial-Intelligence Agency (NGA) and the National
Aeronautics and Space Administration (NASA). Detailed info on the SRTM

GTOPO30 Data Set
5
5500
4
5000
3
4500
2 4000

1 3500
Latitude 0 3000

2500
-1
2000
-2
1500
-3
1000
-4 500

-5 0
30 31 32 33 34 35 36 37 38 39 40
Longitude

Fig. 7.3 Display of the GTOPO30 elevation data set. The map uses the function surf for generating
a gray surface. We use the colormap gray to power of four in order to darken the colormap with
respect to the higher elevation. In addition, we flip the colormap in up/down direction using

flipud to obtain dark colors for high elevations and light colors for low elevations.