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// Part of readsb, a Mode-S/ADSB/TIS message decoder.
//
// cprtests.c - tests for CPR decoder
//
// Copyright (c) 2019 Michael Wolf <michael@mictronics.de>
//
// This code is based on a detached fork of dump1090-fa.
//
// Copyright (c) 2014,2015 Oliver Jowett <oliver@mutability.co.uk>
//
// This file is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// any later version.
//
// This file is distributed in the hope that it will be useful, but
// WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
// General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with this program. If not, see <http://www.gnu.org/licenses/>.
#include <math.h>
#include <stdio.h>
#include "cpr.h"
// Global, airborne CPR test data:
static const struct {
int even_cprlat, even_cprlon; // input: raw CPR values, even message
int odd_cprlat, odd_cprlon; // input: raw CPR values, odd message
int even_result; // verify: expected result from decoding with fflag=0 (even message is latest)
double even_rlat, even_rlon; // verify: expected position from decoding with fflag=0 (even message is latest)
int odd_result; // verify: expected result from decoding with fflag=1 (odd message is latest)
double odd_rlat, odd_rlon; // verify: expected position from decoding with fflag=1 (odd message is latest)
} cprGlobalAirborneTests[] = {
{ 80536, 9432, 61720, 9192, 0, 51.686646, 0.700156, 0, 51.686763, 0.701294},
{ 80534, 9413, 61714, 9144, 0, 51.686554, 0.698745, 0, 51.686484, 0.697632},
// todo: more positions, bad data
};
// Global, surface CPR test data:
static const struct {
double reflat, reflon; // input: reference location for decoding
int even_cprlat, even_cprlon; // input: raw CPR values, even message
int odd_cprlat, odd_cprlon; // input: raw CPR values, odd message
int even_result; // verify: expected result from decoding with fflag=0 (even message is latest)
double even_rlat, even_rlon; // verify: expected position from decoding with fflag=0 (even message is latest)
int odd_result; // verify: expected result from decoding with fflag=1 (odd message is latest)
double odd_rlat, odd_rlon; // verify: expected position from decoding with fflag=1 (odd message is latest)
} cprGlobalSurfaceTests[] = {
// The real position received here was on the Cambridge (UK) airport apron at 52.21N 0.177E
// We mess with the reference location to check that the right quadrant is used.
// longitude quadrants:
{ 52.00, -180.00, 105730, 9259, 29693, 8997, 0, 52.209984, 0.176601 - 180.0, 0, 52.209976, 0.176507 - 180.0},
{ 52.00, -140.00, 105730, 9259, 29693, 8997, 0, 52.209984, 0.176601 - 180.0, 0, 52.209976, 0.176507 - 180.0},
{ 52.00, -130.00, 105730, 9259, 29693, 8997, 0, 52.209984, 0.176601 - 90.0, 0, 52.209976, 0.176507 - 90.0},
{ 52.00, -50.00, 105730, 9259, 29693, 8997, 0, 52.209984, 0.176601 - 90.0, 0, 52.209976, 0.176507 - 90.0},
{ 52.00, -40.00, 105730, 9259, 29693, 8997, 0, 52.209984, 0.176601, 0, 52.209976, 0.176507},
{ 52.00, -10.00, 105730, 9259, 29693, 8997, 0, 52.209984, 0.176601, 0, 52.209976, 0.176507},
{ 52.00, 0.00, 105730, 9259, 29693, 8997, 0, 52.209984, 0.176601, 0, 52.209976, 0.176507},
{ 52.00, 10.00, 105730, 9259, 29693, 8997, 0, 52.209984, 0.176601, 0, 52.209976, 0.176507},
{ 52.00, 40.00, 105730, 9259, 29693, 8997, 0, 52.209984, 0.176601, 0, 52.209976, 0.176507},
{ 52.00, 50.00, 105730, 9259, 29693, 8997, 0, 52.209984, 0.176601 + 90.0, 0, 52.209976, 0.176507 + 90.0},
{ 52.00, 130.00, 105730, 9259, 29693, 8997, 0, 52.209984, 0.176601 + 90.0, 0, 52.209976, 0.176507 + 90.0},
{ 52.00, 140.00, 105730, 9259, 29693, 8997, 0, 52.209984, 0.176601 - 180.0, 0, 52.209976, 0.176507 - 180.0},
{ 52.00, 180.00, 105730, 9259, 29693, 8997, 0, 52.209984, 0.176601 - 180.0, 0, 52.209976, 0.176507 - 180.0},
// latitude quadrants (but only 2). The decoded longitude also changes because the cell size changes with latitude
{ 90.00, 0.00, 105730, 9259, 29693, 8997, 0, 52.209984, 0.176601, 0, 52.209976, 0.176507},
{ 52.00, 0.00, 105730, 9259, 29693, 8997, 0, 52.209984, 0.176601, 0, 52.209976, 0.176507},
{ 8.00, 0.00, 105730, 9259, 29693, 8997, 0, 52.209984, 0.176601, 0, 52.209976, 0.176507},
{ 7.00, 0.00, 105730, 9259, 29693, 8997, 0, 52.209984 - 90.0, 0.135269, 0, 52.209976 - 90.0, 0.134299},
{ -52.00, 0.00, 105730, 9259, 29693, 8997, 0, 52.209984 - 90.0, 0.135269, 0, 52.209976 - 90.0, 0.134299},
{ -90.00, 0.00, 105730, 9259, 29693, 8997, 0, 52.209984 - 90.0, 0.135269, 0, 52.209976 - 90.0, 0.134299},
// poles/equator cases
{ -46.00, -180.00, 0, 0, 0, 0, 0, -90.0, -180.000000, 0, -90.0, -180.0}, // south pole
{ -44.00, -180.00, 0, 0, 0, 0, 0, 0.0, -180.000000, 0, 0.0, -180.0}, // equator
{ 44.00, -180.00, 0, 0, 0, 0, 0, 0.0, -180.000000, 0, 0.0, -180.0}, // equator
{ 46.00, -180.00, 0, 0, 0, 0, 0, 90.0, -180.000000, 0, 90.0, -180.0}, // north pole
};
// Relative CPR test data:
static const struct {
double reflat, reflon; // input: reference location for decoding
int cprlat, cprlon; // input: raw CPR values, even or odd message
int fflag; // input: fflag in raw message
int surface; // input: decode as air (0) or surface (1) position
int result; // verify: expected result
double rlat, rlon; // verify: expected position
} cprRelativeTests[] = {
//
// AIRBORNE
//
{ 52.00, 0.00, 80536, 9432, 0, 0, 0, 51.686646, 0.700156}, // even, airborne
{ 52.00, 0.00, 61720, 9192, 1, 0, 0, 51.686763, 0.701294}, // odd, airborne
{ 52.00, 0.00, 80534, 9413, 0, 0, 0, 51.686554, 0.698745}, // even, airborne
{ 52.00, 0.00, 61714, 9144, 1, 0, 0, 51.686484, 0.697632}, // odd, airborne
// test moving the receiver around a bit
// We cannot move it more than 1/2 cell away before ambiguity happens.
// latitude must be within about 3 degrees (cell size is 360/60 = 6 degrees)
{ 48.70, 0.00, 80536, 9432, 0, 0, 0, 51.686646, 0.700156}, // even, airborne
{ 48.70, 0.00, 61720, 9192, 1, 0, 0, 51.686763, 0.701294}, // odd, airborne
{ 48.70, 0.00, 80534, 9413, 0, 0, 0, 51.686554, 0.698745}, // even, airborne
{ 48.70, 0.00, 61714, 9144, 1, 0, 0, 51.686484, 0.697632}, // odd, airborne
{ 54.60, 0.00, 80536, 9432, 0, 0, 0, 51.686646, 0.700156}, // even, airborne
{ 54.60, 0.00, 61720, 9192, 1, 0, 0, 51.686763, 0.701294}, // odd, airborne
{ 54.60, 0.00, 80534, 9413, 0, 0, 0, 51.686554, 0.698745}, // even, airborne
{ 54.60, 0.00, 61714, 9144, 1, 0, 0, 51.686484, 0.697632}, // odd, airborne
// longitude must be within about 4.8 degrees at this latitude
{ 52.00, 5.40, 80536, 9432, 0, 0, 0, 51.686646, 0.700156}, // even, airborne
{ 52.00, 5.40, 61720, 9192, 1, 0, 0, 51.686763, 0.701294}, // odd, airborne
{ 52.00, 5.40, 80534, 9413, 0, 0, 0, 51.686554, 0.698745}, // even, airborne
{ 52.00, 5.40, 61714, 9144, 1, 0, 0, 51.686484, 0.697632}, // odd, airborne
{ 52.00, -4.10, 80536, 9432, 0, 0, 0, 51.686646, 0.700156}, // even, airborne
{ 52.00, -4.10, 61720, 9192, 1, 0, 0, 51.686763, 0.701294}, // odd, airborne
{ 52.00, -4.10, 80534, 9413, 0, 0, 0, 51.686554, 0.698745}, // even, airborne
{ 52.00, -4.10, 61714, 9144, 1, 0, 0, 51.686484, 0.697632}, // odd, airborne
//
// SURFACE
//
// Surface position on the Cambridge (UK) airport apron at 52.21N 0.18E
{ 52.00, 0.00, 105730, 9259, 0, 1, 0, 52.209984, 0.176601}, // even, surface
{ 52.00, 0.00, 29693, 8997, 1, 1, 0, 52.209976, 0.176507}, // odd, surface
// test moving the receiver around a bit
// We cannot move it more than 1/2 cell away before ambiguity happens.
// latitude must be within about 0.75 degrees (cell size is 90/60 = 1.5 degrees)
{ 51.46, 0.00, 105730, 9259, 0, 1, 0, 52.209984, 0.176601}, // even, surface
{ 51.46, 0.00, 29693, 8997, 1, 1, 0, 52.209976, 0.176507}, // odd, surface
{ 52.95, 0.00, 105730, 9259, 0, 1, 0, 52.209984, 0.176601}, // even, surface
{ 52.95, 0.00, 29693, 8997, 1, 1, 0, 52.209976, 0.176507}, // odd, surface
// longitude must be within about 1.25 degrees at this latitude
{ 52.00, 1.40, 105730, 9259, 0, 1, 0, 52.209984, 0.176601}, // even, surface
{ 52.00, 1.40, 29693, 8997, 1, 1, 0, 52.209976, 0.176507}, // odd, surface
{ 52.00, -1.05, 105730, 9259, 0, 1, 0, 52.209984, 0.176601}, // even, surface
{ 52.00, -1.05, 29693, 8997, 1, 1, 0, 52.209976, 0.176507}, // odd, surface
};
static int testCPRGlobalAirborne() {
int ok = 1;
unsigned i;
for (i = 0; i < sizeof (cprGlobalAirborneTests) / sizeof (cprGlobalAirborneTests[0]); ++i) {
double rlat = 0, rlon = 0;
int res;
res = decodeCPRairborne(cprGlobalAirborneTests[i].even_cprlat, cprGlobalAirborneTests[i].even_cprlon,
cprGlobalAirborneTests[i].odd_cprlat, cprGlobalAirborneTests[i].odd_cprlon,
0,
&rlat, &rlon);
if (res != cprGlobalAirborneTests[i].even_result
|| fabs(rlat - cprGlobalAirborneTests[i].even_rlat) > 1e-6
|| fabs(rlon - cprGlobalAirborneTests[i].even_rlon) > 1e-6) {
ok = 0;
fprintf(stderr,
"testCPRGlobalAirborne[%u,EVEN]: FAIL: decodeCPRairborne(%d,%d,%d,%d,EVEN) failed:\n"
" result %d (expected %d)\n"
" lat %.6f (expected %.6f)\n"
" lon %.6f (expected %.6f)\n",
i,
cprGlobalAirborneTests[i].even_cprlat, cprGlobalAirborneTests[i].even_cprlon,
cprGlobalAirborneTests[i].odd_cprlat, cprGlobalAirborneTests[i].odd_cprlon,
res, cprGlobalAirborneTests[i].even_result,
rlat, cprGlobalAirborneTests[i].even_rlat,
rlon, cprGlobalAirborneTests[i].even_rlon);
} else {
fprintf(stderr, "testCPRGlobalAirborne[%u,EVEN]: PASS\n", i);
}
res = decodeCPRairborne(cprGlobalAirborneTests[i].even_cprlat, cprGlobalAirborneTests[i].even_cprlon,
cprGlobalAirborneTests[i].odd_cprlat, cprGlobalAirborneTests[i].odd_cprlon,
1,
&rlat, &rlon);
if (res != cprGlobalAirborneTests[i].odd_result
|| fabs(rlat - cprGlobalAirborneTests[i].odd_rlat) > 1e-6
|| fabs(rlon - cprGlobalAirborneTests[i].odd_rlon) > 1e-6) {
ok = 0;
fprintf(stderr,
"testCPRGlobalAirborne[%u,ODD]: FAIL: decodeCPRairborne(%d,%d,%d,%d,ODD) failed:\n"
" result %d (expected %d)\n"
" lat %.6f (expected %.6f)\n"
" lon %.6f (expected %.6f)\n",
i,
cprGlobalAirborneTests[i].even_cprlat, cprGlobalAirborneTests[i].even_cprlon,
cprGlobalAirborneTests[i].odd_cprlat, cprGlobalAirborneTests[i].odd_cprlon,
res, cprGlobalAirborneTests[i].odd_result,
rlat, cprGlobalAirborneTests[i].odd_rlat,
rlon, cprGlobalAirborneTests[i].odd_rlon);
} else {
fprintf(stderr, "testCPRGlobalAirborne[%u,ODD]: PASS\n", i);
}
}
return ok;
}
static int testCPRGlobalSurface() {
int ok = 1;
unsigned i;
for (i = 0; i < sizeof (cprGlobalSurfaceTests) / sizeof (cprGlobalSurfaceTests[0]); ++i) {
double rlat = 0, rlon = 0;
int res;
res = decodeCPRsurface(cprGlobalSurfaceTests[i].reflat, cprGlobalSurfaceTests[i].reflon,
cprGlobalSurfaceTests[i].even_cprlat, cprGlobalSurfaceTests[i].even_cprlon,
cprGlobalSurfaceTests[i].odd_cprlat, cprGlobalSurfaceTests[i].odd_cprlon,
0,
&rlat, &rlon);
if (res != cprGlobalSurfaceTests[i].even_result
|| fabs(rlat - cprGlobalSurfaceTests[i].even_rlat) > 1e-6
|| fabs(rlon - cprGlobalSurfaceTests[i].even_rlon) > 1e-6) {
ok = 0;
fprintf(stderr,
"testCPRGlobalSurface[%u,EVEN]: FAIL: decodeCPRsurface(%.6f,%.6f,%d,%d,%d,%d,EVEN) failed:\n"
" result %d (expected %d)\n"
" lat %.6f (expected %.6f)\n"
" lon %.6f (expected %.6f)\n",
i,
cprGlobalSurfaceTests[i].reflat, cprGlobalSurfaceTests[i].reflon,
cprGlobalSurfaceTests[i].even_cprlat, cprGlobalSurfaceTests[i].even_cprlon,
cprGlobalSurfaceTests[i].odd_cprlat, cprGlobalSurfaceTests[i].odd_cprlon,
res, cprGlobalSurfaceTests[i].even_result,
rlat, cprGlobalSurfaceTests[i].even_rlat,
rlon, cprGlobalSurfaceTests[i].even_rlon);
} else {
fprintf(stderr, "testCPRGlobalSurface[%u,EVEN]: PASS\n", i);
}
res = decodeCPRsurface(cprGlobalSurfaceTests[i].reflat, cprGlobalSurfaceTests[i].reflon,
cprGlobalSurfaceTests[i].even_cprlat, cprGlobalSurfaceTests[i].even_cprlon,
cprGlobalSurfaceTests[i].odd_cprlat, cprGlobalSurfaceTests[i].odd_cprlon,
1,
&rlat, &rlon);
if (res != cprGlobalSurfaceTests[i].odd_result
|| fabs(rlat - cprGlobalSurfaceTests[i].odd_rlat) > 1e-6
|| fabs(rlon - cprGlobalSurfaceTests[i].odd_rlon) > 1e-6) {
ok = 0;
fprintf(stderr,
"testCPRGlobalSurface[%u,ODD]: FAIL: decodeCPRsurface(%.6f,%.6f,%d,%d,%d,%d,ODD) failed:\n"
" result %d (expected %d)\n"
" lat %.6f (expected %.6f)\n"
" lon %.6f (expected %.6f)\n",
i,
cprGlobalSurfaceTests[i].reflat, cprGlobalSurfaceTests[i].reflon,
cprGlobalSurfaceTests[i].even_cprlat, cprGlobalSurfaceTests[i].even_cprlon,
cprGlobalSurfaceTests[i].odd_cprlat, cprGlobalSurfaceTests[i].odd_cprlon,
res, cprGlobalSurfaceTests[i].odd_result,
rlat, cprGlobalSurfaceTests[i].odd_rlat,
rlon, cprGlobalSurfaceTests[i].odd_rlon);
} else {
fprintf(stderr, "testCPRGlobalSurface[%u,ODD]: PASS\n", i);
}
}
return ok;
}
static int testCPRRelative() {
int ok = 1;
unsigned i;
for (i = 0; i < sizeof (cprRelativeTests) / sizeof (cprRelativeTests[0]); ++i) {
double rlat = 0, rlon = 0;
int res;
res = decodeCPRrelative(cprRelativeTests[i].reflat, cprRelativeTests[i].reflon,
cprRelativeTests[i].cprlat, cprRelativeTests[i].cprlon,
cprRelativeTests[i].fflag, cprRelativeTests[i].surface,
&rlat, &rlon);
if (res != cprRelativeTests[i].result
|| fabs(rlat - cprRelativeTests[i].rlat) > 1e-6
|| fabs(rlon - cprRelativeTests[i].rlon) > 1e-6) {
ok = 0;
fprintf(stderr,
"testCPRRelative[%u]: FAIL: decodeCPRrelative(%.6f,%.6f,%d,%d,%d,%d) failed:\n"
" result %d (expected %d)\n"
" lat %.6f (expected %.6f)\n"
" lon %.6f (expected %.6f)\n",
i,
cprRelativeTests[i].reflat, cprRelativeTests[i].reflon,
cprRelativeTests[i].cprlat, cprRelativeTests[i].cprlon,
cprRelativeTests[i].fflag, cprRelativeTests[i].surface,
res, cprRelativeTests[i].result,
rlat, cprRelativeTests[i].rlat,
rlon, cprRelativeTests[i].rlon);
} else {
fprintf(stderr, "testCPRRelative[%u]: PASS\n", i);
}
}
return ok;
}
int main(int __attribute__ ((unused)) argc, char __attribute__ ((unused)) **argv) {
int ok = 1;
ok = testCPRGlobalAirborne() && ok;
ok = testCPRGlobalSurface() && ok;
ok = testCPRRelative() && ok;
return ok ? 0 : 1;
}
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