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/*
* Copyright (C) 2005-2022 Centre National d'Etudes Spatiales (CNES)
*
* This file is part of Orfeo Toolbox
*
* https://www.orfeo-toolbox.org/
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
/* Example usage:
./DEMHandlerExample Input/DEM/srtm_directory Input/DEM/egm96.grd 40 8.434583 44.647083 383.580313671 0.001
*/
// Since release 8.0, OTB relies on GDAL for elevation handling. Since release 3.16,
// there is a single configuration class \doxygen{otb}{DEMHandler} to manage elevation
// (in image projections or localization functions for example). This configuration
// is managed by the a proper instantiation and parameters setting of this
// class. These instantiations must be done before any call to geometric
// filters or functionalities. GDAL internal accesses to elevation are also
// configured by this class and this will ensure consistency throughout the
// library.
#include "otbDEMHandler.h"
int main(int argc, char* argv[])
{
if (argc != 8)
{
std::cerr << "Usage: " << argv[0] << " demdir[path|no] geoid[path|no] defaultHeight longitude latitude targetValue tolerance" << std::endl;
return EXIT_FAILURE;
}
std::string demdir = argv[1];
std::string geoid = argv[2];
double defaultHeight = atof(argv[3]);
double longitude = atof(argv[4]);
double latitude = atof(argv[5]);
double target = atof(argv[6]);
double tolerance = atof(argv[7]);
// This class is a singleton, the New() method is deprecated and will be removed
// in future release. We need to use the \code{Instance()} method instead.
auto & demHandler = otb::DEMHandler::GetInstance();
bool fail = false;
// It allows configuring a directory containing DEM tiles (DTED or SRTM
// supported) using the \code{OpenDEMDirectory()} method. The \code{OpenGeoidFile()} method
// allows inputting a geoid file as well. Last, a default height above ellipsoid
// can be set using the \code{SetDefaultHeightAboveEllipsoid()} method.
demHandler.SetDefaultHeightAboveEllipsoid(defaultHeight);
if (!demHandler.IsValidDEMDirectory(demdir.c_str()))
{
std::cerr << "IsValidDEMDirectory(" << demdir << ") = false" << std::endl;
fail = true;
}
demHandler.OpenDEMDirectory(demdir);
demHandler.OpenGeoidFile(geoid);
// We can now retrieve height above ellipsoid or height above Mean Sea Level
// (MSL) using the methods \code{GetHeightAboveEllipsoid()} and
// \code{GetHeightAboveMSL()}. Outputs of these methods depend on the
// configuration of the class \doxygen{otb}{DEMHandler} and the different
// cases are:
//
// For \code{GetHeightAboveEllipsoid()}:
//
// \begin{itemize}
// \item DEM and geoid both available: $dem\_value + geoid\_offset$
// \item No DEM but geoid available: geoid\_offset
// \item DEM available, but no geoid: dem\_value
// \item No DEM and no geoid available: default height above ellipsoid
// \end{itemize}
//
// For \code{GetHeightAboveMSL()}:
//
// \begin{itemize}
// \item DEM and geoid both available: srtm\_value
// \item No DEM but geoid available: $0$
// \item DEM available, but no geoid: srtm\_value
// \item No DEM and no geoid available: $0$
// \end{itemize}
otb::DEMHandler::PointType point;
point[0] = longitude;
point[1] = latitude;
double height = -32768;
height = demHandler.GetHeightAboveMSL(point);
std::cout << "height above MSL (" << longitude << "," << latitude << ") = " << height << " meters" << std::endl;
height = demHandler.GetHeightAboveEllipsoid(point);
std::cout << "height above ellipsoid (" << longitude << ", " << latitude << ") = " << height << " meters" << std::endl;
// Check for Nan
if (vnl_math_isnan(height))
{
std::cerr << "Computed value is NaN" << std::endl;
fail = true;
}
double error = std::abs(height - target);
if (error > tolerance)
{
std::cerr << "Target value is " << target << " meters, computed value is " << height << " meters. error (" << error << " meters) > tolerance (" << tolerance
<< " meters)" << std::endl;
fail = true;
}
if (fail)
{
return EXIT_FAILURE;
}
return EXIT_SUCCESS;
}
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