IEEE Geoscience and Remote Sensing Magazine - December 2020 - 140

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be done by incorporating syllabi related to generating DEMs; characterizing their errors; devising descriptors via geometry, algebra, physics,
and mathematics; developing physics-based algorithms for processing
and analysis DEMs; and processing
and analyzing DEMs using robust
spatial algorithms. This dedicated,
mathematically sound curriculum
should be developed as a joint effort
with mathematicians, statisticians,
and scientists drawn from across
disciplines: cartographers, computer engineers, photogrammetrists, and
remote sensing specialists.

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(c)
FIGURE 2. (a) An SRTM DEM of the lower Indus River subbasin, (b) a watershed-wise classification based on global roughness indexes computed using granulometric analysis, and (c)
a watershed-wise classification of high-directional granulometric index values computed via
directional granulometric analysis. For mathematical details, see [55].

geosciences, should be made mandatory, as should the
necessary foundational mathematical courses required
for these studies. This will both foster the self-reliance
described previously and broaden the interdisciplinary
nature of the field.
DEMs themselves are rich enough as a subject to warrant inclusion as a full-length subject at undergraduate
and postgraduate levels, establishing a rigorous curriculum to train the next generation of geoscientists. This can
140

ACKNOWLEDGMENTS
Discussions via personal communications with Dr. Paul Rosen on the
initial version and with Prof. Gabor
Korvin on both versions helped improve the article significantly. The
author is also grateful to the anonymous reviewers and the editor-inchief, Prof. James Garrison, for their
constructive criticism and many suggestions that helped strengthen this
opinion piece.
AUTHOR INFORMATION
B.S. Daya Sagar (bsdsagar@isibang
.ac.in) is a full professor at the Systems
Science and Informatics Unit, Indian
Statistical Institute, Bangalore Centre,
India. His research interests include
mathematical morphology; geographic information sciences; digital image
processing; and fractals and multifractals and their applications in extraction,
analyses, and modeling of geophysical
patterns. He is an IEEE Geoscience and
Remote Sensing Society (GRSS) Distinguished Lecturer for 2020-2022.
He is a Senior Member of IEEE and
the GRSS.

REFERENCES
[1]	 G. H. Rosenfield, " Stereo radar techniques, " Photogramm. Eng.,
vol. 34, no. 6, pp. 586-594, 1968.
[2]	 R. M. Goldstein and H. A. Zebker, " Two-dimensional phase unwrapping, " Radio Sci., vol. 23, no. 4, pp. 713-720, 1988. doi: 10.1029/
RS023i004p00713.
[3]	 T. Toutin, " Generating DEM from stereo images with a photogrammetric approach: Examples with VIR and SAR data, " EARSeL J. Adv. Remote Sens., vol. 4, no. 2, pp. 110-117, 1995.
IEEE GEOSCIENCE AND REMOTE SENSING MAGAZINE

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IEEE Geoscience and Remote Sensing Magazine - December 2020

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