A 3-D DIGITAL TERRAIN MODEL ORIENTED TO
DESIGN A CLUTTER PREDICTOR
E. Gonzalez-Ramirez (1), I. D. Cluckie (1), M. Tecpoyotl-Torres (2), M. A.
Rico-Ramirez (1), G. Cerda-Villafaña (1), J. Escobedo-Alatorre (2) and J.
(1) Water and Environmental Management Research Centre (WEMRC), University of Bristol.
(2) Research Center of Applied Sciences and Engineering (CIICAp), Autonomous University
of Morelos State (UAEM), firstname.lastname@example.org /Fax: +52 777 3297084.
The variation of rainfall intensity with height makes mandatory to look at rainfall as
close to the ground as possible when scanning the atmosphere by means of weather
radars. Using small elevation angles is a logical strategy for this. Weather radar mea-
surements contain many errors, which reduce the quality of the rainfall data. Ground
clutter has a strong relationship with the beam elevation angle and the Digital Terrain
Model (DTM) around the radar site.
Clutter is present when the radar beam intercepts obstacles creating a beam blockage
reflecting back part of the incident energy. Due to this relationship it is possible to
predict clutter from a DTM by calculating the amount of the "blocked" energy.
In this paper we present a software tool able to manipulate a DTM in order to de-
sign a clutter predictor for weather radar. Visual C++ has been used as a programming
language together with opengl libraries and MFC classes. This software allows the ex-
ploring of the image in four directions (North, South, East and West), rotate it, zoom
in and out, calculate geographic parameters (distance between two points, true north,
true azimuth of a point with respect to a reference point, conversion among coordi-
nate systems, etc.), and have functions to deal with the radar propagation through the
atmosphere (Earth curvature, beam bending due to refractive index and calculation of
the height when increasing range).
Software able to display a DTM in 3-dimensions is available but it is not possible to
manipulate data according to the specific necessit