1 October 2003
Figure 5-24. Digital elevation model (DEM). The brightness
values in this image represent elevation data. Dark pixels cor-
respond to low elevations while the brightest pixels represent
higher elevations. Taken from the NASA tutorial at
(c) DEMs can be created for a study site with the use of a high resolution
raster topographic map. The method involved in creating a DEM is fairly ad-
getting starting in DEM production.
(4) Advanced Methods in Image Processing. Remote sensing software fa-
cilitates a number of advanced image processing methods. These advanced meth-
ods include the processing of hyperspectral data, thermal data, radar data, spectral
library development, and inter-software programming.
(a) Hyperspectral Data. Hyperspectral image processing techniques
manage narrow, continuous bands of spectral data. Many hyperspectral systems
maintain over 200 bands of spectral data. The narrow bands, also known as chan-
nels, provide a high level of detail and resolution. This high resolution facilitates
the identification of specific objects, thereby improving classification (Figure 5-
24). The advantage of hyperspectral imaging lies in its ability to distinguish indi-
vidual objects that would be otherwise grouped in broadband multi-spectra im-
agery. Narrow bands are particularly useful for mapping resources such as crop
and mineral types. The narrow, nearly continuous bands create large data sets,
which require advance software and hardware to store and manipulate the data.