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1 | 1 | //-*- C++ -*- |
2 | | -//-*- coding: utf-8 -*- |
3 | | -// |
4 | | -// Author: Bryan Riel |
5 | | -// Copyright 2018 |
6 | | -// |
7 | 2 |
|
8 | 3 | #include <iostream> |
9 | 4 | #include <string> |
| 5 | +#include <cmath> |
10 | 6 | #include <gtest/gtest.h> |
11 | 7 |
|
12 | 8 | // isce3::core |
@@ -49,6 +45,264 @@ TEST(DEMTest, MethodConstruct) { |
49 | 45 | } |
50 | 46 | } |
51 | 47 |
|
| 48 | + |
| 49 | +void test_dateline(double x0, double xf, double y0, double yf, |
| 50 | + double sampling_factor) { |
| 51 | + /* |
| 52 | + This function uses two geoid rasters (EGM96) to test the DEM |
| 53 | + interpolator for dateline crossing. The geoid raster "egm96_15.gtx" |
| 54 | + is geolocated over geographic coordinates with longitude range |
| 55 | + varying from -180 to 180 deg whereas the geoid raster |
| 56 | + "egm96_15_lon_0_360.gtx" is the "shifted" version of "egm96_15.gtx" |
| 57 | + geolocated over geographic coordinates with longitude from 0 to 360 deg. |
| 58 | + We compare the interpolated values from DEMInterpolator methods |
| 59 | + interpolateLonLat() and interpolateXY(). |
| 60 | + The `sampling_factor` determines the lat/lon step w.r.t. the geoid |
| 61 | + rasters pixel size. |
| 62 | + We compare the values from the four sources: |
| 63 | + 1 - Non-interpolated "egm96_15.gtx" values; |
| 64 | + 2 - Non-interpolated "egm96_15_lon_0_360.gtx" values; |
| 65 | + 3 - DEMInterpolator "egm96_15.gtx" values; |
| 66 | + 4 - DEMInterpolator "egm96_15_lon_0_360.gtx" values. |
| 67 | + The non-interpolated values 1 and 2 are only compared to the |
| 68 | + DEMInterpolator values 3 and 4 for the points located in the |
| 69 | + center of the pixel (where no interpolation is required). |
| 70 | + */ |
| 71 | + |
| 72 | + std::cout << "testing DEM interpolator with bbox:" << std::endl; |
| 73 | + std::cout << " start lon: " << x0 << std::endl; |
| 74 | + std::cout << " end lon: " << xf << std::endl; |
| 75 | + std::cout << " start lat: " << y0 << std::endl; |
| 76 | + std::cout << " end lat: " << yf << std::endl; |
| 77 | + |
| 78 | + // create geoid raster objects |
| 79 | + isce3::io::Raster raster_geoid(TESTDATA_DIR "egm96_15.gtx"); |
| 80 | + isce3::io::Raster raster_geoid_0_to_360(TESTDATA_DIR "egm96_15_lon_0_360.gtx"); |
| 81 | + |
| 82 | + // setup geoid DEM interpolators |
| 83 | + isce3::geometry::DEMInterpolator dem_interp_geoid(0, |
| 84 | + isce3::core::dataInterpMethod::BIQUINTIC_METHOD); |
| 85 | + auto ret_1 = dem_interp_geoid.loadDEM(raster_geoid, x0, xf, y0, yf); |
| 86 | + if (ret_1 != isce3::error::ErrorCode::Success) { |
| 87 | + throw std::runtime_error("loadDEM failed"); |
| 88 | + } |
| 89 | + |
| 90 | + isce3::geometry::DEMInterpolator dem_interp_geoid_0_to_360(0, |
| 91 | + isce3::core::dataInterpMethod::BIQUINTIC_METHOD); |
| 92 | + auto ret_2 = dem_interp_geoid_0_to_360.loadDEM(raster_geoid_0_to_360, x0, xf, y0, |
| 93 | + yf); |
| 94 | + if (ret_2 != isce3::error::ErrorCode::Success) { |
| 95 | + throw std::runtime_error("loadDEM failed"); |
| 96 | + } |
| 97 | + |
| 98 | + // read geoid raster |
| 99 | + auto width = raster_geoid.width(); |
| 100 | + auto length = raster_geoid.length(); |
| 101 | + auto dx = raster_geoid.dx(); |
| 102 | + auto dy = raster_geoid.dy(); |
| 103 | + ASSERT_GT(dx, 0); |
| 104 | + ASSERT_LT(dy, 0); |
| 105 | + |
| 106 | + isce3::core::Matrix<float> geoid_array(length, width); |
| 107 | + raster_geoid.getBlock(geoid_array.data(), 0, 0, width, length, 1); |
| 108 | + |
| 109 | + isce3::core::Matrix<float> geoid_array_0_to_360(length, width); |
| 110 | + raster_geoid_0_to_360.getBlock(geoid_array_0_to_360.data(), 0, 0, |
| 111 | + width, length, 1); |
| 112 | + |
| 113 | + const int interpolation_margin = 5; |
| 114 | + const double err_tolerance = 1e-6; |
| 115 | + |
| 116 | + // Fix `xf` to be used by for loop |
| 117 | + if (xf < x0) { |
| 118 | + xf += 360; |
| 119 | + } |
| 120 | + |
| 121 | + for (double lat = yf + interpolation_margin * dy; |
| 122 | + lat > y0 - interpolation_margin * dy; |
| 123 | + lat += sampling_factor * dy) { |
| 124 | + |
| 125 | + int lat_idx = (lat - 90) / dy; |
| 126 | + |
| 127 | + for (double lon = x0 + interpolation_margin * dx; |
| 128 | + lon < xf - interpolation_margin * dx; |
| 129 | + lon += sampling_factor * dx) { |
| 130 | + |
| 131 | + /* |
| 132 | + The non-interpolated values `geoid_array` and |
| 133 | + `geoid_array_0_to_360` are only compared to the DEMInterpolator |
| 134 | + values 3 and 4 for the points located in the center of the pixel |
| 135 | + (where no interpolation is required). This condition is |
| 136 | + represented by the flag `flag_check_arrays`. |
| 137 | + */ |
| 138 | + bool flag_check_arrays = |
| 139 | + (std::fmod(lat, dy) == 0.0) && |
| 140 | + (std::fmod(lon, dx) == 0.0) && |
| 141 | + lat_idx < length; |
| 142 | + |
| 143 | + int lon_idx; |
| 144 | + if (flag_check_arrays) { |
| 145 | + |
| 146 | + // Wrap `lon` to longitude range [-180, 360] |
| 147 | + double lon_wrapped = lon; |
| 148 | + if (lon > 360 || lon < -360) { |
| 149 | + lon_wrapped = std::fmod(lon, 360); |
| 150 | + } |
| 151 | + |
| 152 | + if (lon < -180 - dx) { |
| 153 | + lon_wrapped += 360; |
| 154 | + } |
| 155 | + |
| 156 | + if (lon_wrapped < 180) { |
| 157 | + lon_idx = (lon_wrapped + 180) / dx; |
| 158 | + } else { |
| 159 | + lon_idx = (lon_wrapped - 180) / dx; |
| 160 | + } |
| 161 | + |
| 162 | + int lon_idx_0_to_360; |
| 163 | + if (lon_wrapped >= 0) { |
| 164 | + lon_idx_0_to_360 = lon_wrapped / dx; |
| 165 | + } else { |
| 166 | + lon_idx_0_to_360 = (lon_wrapped + 360) / dx; |
| 167 | + } |
| 168 | + |
| 169 | + /* Check if indexes `lon_idx` and `lon_idx_0_to_360` |
| 170 | + are within arrays' dimensions. If not, set |
| 171 | + `flag_check_arrays` to false. |
| 172 | + */ |
| 173 | + if (lon_idx >= width || lon_idx_0_to_360 >= width) { |
| 174 | + flag_check_arrays = false; |
| 175 | + } else { |
| 176 | + // compare raster values (without interpolation) |
| 177 | + ASSERT_NEAR(geoid_array(lat_idx, lon_idx), |
| 178 | + geoid_array_0_to_360(lat_idx, lon_idx_0_to_360), |
| 179 | + err_tolerance); |
| 180 | + } |
| 181 | + } |
| 182 | + |
| 183 | + // test interpolateLonLat() |
| 184 | + double deg_to_rad_factor = M_PI / 180.0; |
| 185 | + double geoid_value = dem_interp_geoid.interpolateLonLat( |
| 186 | + lon * deg_to_rad_factor, lat * deg_to_rad_factor); |
| 187 | + |
| 188 | + double geoid_0_to_360_value = |
| 189 | + dem_interp_geoid_0_to_360.interpolateLonLat( |
| 190 | + lon * deg_to_rad_factor, lat * deg_to_rad_factor); |
| 191 | + |
| 192 | + if (flag_check_arrays) { |
| 193 | + ASSERT_NEAR(geoid_array(lat_idx, lon_idx), |
| 194 | + geoid_value, err_tolerance); |
| 195 | + ASSERT_NEAR(geoid_array( |
| 196 | + lat_idx, lon_idx), geoid_0_to_360_value, |
| 197 | + err_tolerance); |
| 198 | + } |
| 199 | + |
| 200 | + // test interpolateXY() |
| 201 | + double geoid_value_xy = dem_interp_geoid.interpolateXY(lon, lat); |
| 202 | + double geoid_0_to_360_value_xy = |
| 203 | + dem_interp_geoid_0_to_360.interpolateXY(lon, lat); |
| 204 | + |
| 205 | + ASSERT_NEAR(geoid_value, geoid_0_to_360_value, err_tolerance); |
| 206 | + ASSERT_NEAR( |
| 207 | + geoid_value_xy, geoid_0_to_360_value_xy, err_tolerance); |
| 208 | + } |
| 209 | + } |
| 210 | +} |
| 211 | + |
| 212 | + |
| 213 | +TEST(DEMTest, DatelineCrossing) { |
| 214 | + |
| 215 | + std::cout << "dateline crossing test" << std::endl; |
| 216 | + |
| 217 | + double y0 = -90, yf = 90; |
| 218 | + |
| 219 | + // offset test wrapping of longitude coordinates around 360 degrees |
| 220 | + for (int offset = -360; offset <= 360; offset += 360) { |
| 221 | + std::cout << "offset:" << offset << std::endl; |
| 222 | + |
| 223 | + // global with longitude range [-180, 180] |
| 224 | + double sampling_factor = 4; |
| 225 | + double x0 = -180 + offset; |
| 226 | + double xf = 180 + offset; |
| 227 | + test_dateline(x0, xf, y0, yf, sampling_factor); |
| 228 | + |
| 229 | + // global with longitude range [0, 360] |
| 230 | + x0 = 0 + offset; |
| 231 | + xf = 360 + offset; |
| 232 | + test_dateline(x0, xf, y0, yf, sampling_factor); |
| 233 | + |
| 234 | + // longitude values within ]-180, 0[ |
| 235 | + x0 = -170 + offset; |
| 236 | + xf = -10 + offset; |
| 237 | + test_dateline(x0, xf, y0, yf, sampling_factor); |
| 238 | + |
| 239 | + // longitude values within ]0, 180[ |
| 240 | + x0 = 10 + offset; |
| 241 | + xf = 170 + offset; |
| 242 | + test_dateline(x0, xf, y0, yf, sampling_factor); |
| 243 | + |
| 244 | + // longitude values within ]180, 360[ |
| 245 | + x0 = 190 + offset; |
| 246 | + xf = 350 + offset; |
| 247 | + test_dateline(x0, xf, y0, yf, sampling_factor); |
| 248 | + |
| 249 | + // dateline 179.5 to 180.5 |
| 250 | + sampling_factor = 0.05; |
| 251 | + x0 = 179.5 + offset; |
| 252 | + xf = 180.5 + offset; |
| 253 | + test_dateline(x0, xf, y0, yf, sampling_factor); |
| 254 | + |
| 255 | + // test DEM right edges |
| 256 | + x0 = 179 + offset; |
| 257 | + xf = 179.875 + offset; |
| 258 | + test_dateline(x0, xf, y0, yf, sampling_factor); |
| 259 | + |
| 260 | + x0 = 359 + offset; |
| 261 | + xf = 359.875 + offset; |
| 262 | + test_dateline(x0, xf, y0, yf, sampling_factor); |
| 263 | + |
| 264 | + // test DEM right edges (global) |
| 265 | + sampling_factor = 8; |
| 266 | + x0 = -180 + offset; |
| 267 | + xf = 179.875 + offset; |
| 268 | + test_dateline(x0, xf, y0, yf, sampling_factor); |
| 269 | + |
| 270 | + x0 = 0 + offset; |
| 271 | + xf = 359.875 + offset; |
| 272 | + test_dateline(x0, xf, y0, yf, sampling_factor); |
| 273 | + |
| 274 | + // test DEM left edges |
| 275 | + sampling_factor = 0.05; |
| 276 | + x0 = -180.125 + offset; |
| 277 | + xf = -179 + offset; |
| 278 | + test_dateline(x0, xf, y0, yf, sampling_factor); |
| 279 | + |
| 280 | + x0 = -0.125 + offset; |
| 281 | + xf = 1.0 + offset; |
| 282 | + test_dateline(x0, xf, y0, yf, sampling_factor); |
| 283 | + |
| 284 | + // test DEM left edges (global) |
| 285 | + sampling_factor = 8; |
| 286 | + x0 = -180.125 + offset; |
| 287 | + xf = 179.875 + offset; |
| 288 | + test_dateline(x0, xf, y0, yf, sampling_factor); |
| 289 | + |
| 290 | + x0 = -0.125 + offset; |
| 291 | + xf = 359.875 + offset; |
| 292 | + test_dateline(x0, xf, y0, yf, sampling_factor); |
| 293 | + |
| 294 | + if (offset == 0) { |
| 295 | + |
| 296 | + // dateline 179.5 to -179.5 |
| 297 | + x0 = 179.5 + offset; |
| 298 | + xf = -179.5 + offset; |
| 299 | + test_dateline(x0, xf, y0, yf, sampling_factor); |
| 300 | + |
| 301 | + } |
| 302 | + } |
| 303 | +} |
| 304 | + |
| 305 | + |
52 | 306 | int main(int argc, char * argv[]) { |
53 | 307 | testing::InitGoogleTest(&argc, argv); |
54 | 308 | return RUN_ALL_TESTS(); |
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