double horizons[2];
int errnum;
- double clutter_loss; // loss due to vegetation and urban
+ double clutter_loss = 0.0; // loss due to vegetation and urban
double tx_pow = _transmitter_power;
double ant_gain = _antenna_gain;
double signal = 0.0;
SG_LOG(SG_GENERAL, SG_BULK,
"ITM:: RX-height: " << receiver_height << " meters, TX-height: " << transmitter_height << " meters, Distance: " << distance_m << " meters");
- //cerr << "ITM:: RX-height: " << receiver_height << " meters, TX-height: " << transmitter_height << " meters, Distance: " << distance_m << " meters" << endl;
+ cerr << "ITM:: RX-height: " << receiver_height << " meters, TX-height: " << transmitter_height << " meters, Distance: " << distance_m << " meters" << endl;
unsigned int e_size = (deque<unsigned>::size_type)max_points;
double horizons[], double &clutter_loss) {
if (p_mode == 0) { // LOS: take each point and see how clutter height affects first Fresnel zone
+ int mat = 0;
int j=1; // first point is TX elevation, last is RX elevation
for (int k=3;k < (int)itm_elev[0];k++) {
double clutter_height = 0.0; // mean clutter height for a certain terrain type
double clutter_density = 0.0; // percent of reflected wave
- get_material_properties(materials[j-1], clutter_height, clutter_density);
- //cerr << "Clutter:: material: " << materials[j-1] << " height: " << clutter_height << ", density: " << clutter_density << endl;
- double grad = fabs(itm_elev[2] + transmitter_height - itm_elev[(int)itm_elev[0] + 2] + receiver_height) / distance_m;
+ get_material_properties(materials[mat], clutter_height, clutter_density);
+ //cerr << "Clutter:: material: " << materials[mat] << " height: " << clutter_height << ", density: " << clutter_density << endl;
+ double grad = fabs(itm_elev[2] + transmitter_height - itm_elev[(int)itm_elev[0] + 1] + receiver_height) / distance_m;
// First Fresnel radius
double frs_rad = 548 * sqrt( (j * itm_elev[1] * (itm_elev[0] - j) * itm_elev[1] / 1000000) / ( distance_m * freq / 1000) );
//cerr << "Clutter:: fresnel radius: " << frs_rad << endl;
//double earth_h = distance_m * (distance_m - j * itm_elev[1]) / ( 1000000 * 12.75 * 1.33 ); // K=4/3
- double min_elev = SGMiscd::min(itm_elev[2] + transmitter_height, itm_elev[(int)itm_elev[0] + 2] + receiver_height);
+ double min_elev = SGMiscd::min(itm_elev[2] + transmitter_height, itm_elev[(int)itm_elev[0] + 1] + receiver_height);
double d1 = j * itm_elev[1];
- if ((itm_elev[2] + transmitter_height) > ( itm_elev[(int)itm_elev[0] + 2] + receiver_height) ) {
+ if ((itm_elev[2] + transmitter_height) > ( itm_elev[(int)itm_elev[0] + 1] + receiver_height) ) {
d1 = (itm_elev[0] - j) * itm_elev[1];
}
double ray_height = (grad * d1) + min_elev;
- cerr << "Clutter:: ray height: " << ray_height << " ground height:" << itm_elev[k] << endl;
+ //cerr << "Clutter:: ray height: " << ray_height << " ground height:" << itm_elev[k] << endl;
double clearance = ray_height - (itm_elev[k] + clutter_height) - frs_rad * 8/10;
double intrusion = fabs(clearance);
//cerr << "Clutter:: clearance: " << clearance << endl;
if (clearance >= 0) {
- clutter_loss +=0.0;
+ // no losses
}
else if (clearance < 0 && (intrusion < clutter_height)) {
clutter_loss += clutter_density * (clutter_height / (frs_rad * 2 ) ) * freq/100;
}
else {
- clutter_loss += 0.0;
+ // no losses
}
j++;
+ mat++;
}
}
else if (p_mode == 1) { // diffraction
if (horizons[1] == 0.0) { // single horizon: same as above, except pass twice using the highest point
- int num_points_1st = (int)floor( horizons[1] * (double)itm_elev[0] / distance_m );
- int num_points_2nd = (int)floor( (distance_m - horizons[1]) * (double)itm_elev[0] / distance_m );
+ int num_points_1st = (int)floor( horizons[0] * (double)itm_elev[0] / distance_m );
+ int num_points_2nd = (int)floor( (distance_m - horizons[0]) * (double)itm_elev[0] / distance_m );
int last = 1;
/** perform the first pass */
-
- int j=1; // first point is TX elevation, last is obstruction elevation
+ int mat = 0;
+ int j=1; // first point is TX elevation, 2nd is obstruction elevation
for (int k=3;k < num_points_1st ;k++) {
double clutter_height = 0.0; // mean clutter height for a certain terrain type
double clutter_density = 0.0; // percent of reflected wave
- get_material_properties(materials[j-1], clutter_height, clutter_density);
- //cerr << "Clutter:: material: " << materials[j-1] << " height: " << clutter_height << ", density: " << clutter_density << endl;
- double grad = fabs(itm_elev[2] + transmitter_height - itm_elev[num_points_1st + 2] + clutter_height) / distance_m;
+ get_material_properties(materials[mat], clutter_height, clutter_density);
+ //cerr << "Clutter:: material: " << materials[mat] << " height: " << clutter_height << ", density: " << clutter_density << endl;
+ double grad = fabs(itm_elev[2] + transmitter_height - itm_elev[num_points_1st + 1] + clutter_height) / distance_m;
// First Fresnel radius
double frs_rad = 548 * sqrt( (j * itm_elev[1] * (num_points_1st - j) * itm_elev[1] / 1000000) / ( num_points_1st * itm_elev[1] * freq / 1000) );
//cerr << "Clutter:: fresnel radius: " << frs_rad << endl;
//double earth_h = distance_m * (distance_m - j * itm_elev[1]) / ( 1000000 * 12.75 * 1.33 ); // K=4/3
- double min_elev = SGMiscd::min(itm_elev[2] + transmitter_height, itm_elev[num_points_1st + 2] + clutter_height);
+ double min_elev = SGMiscd::min(itm_elev[2] + transmitter_height, itm_elev[num_points_1st + 1] + clutter_height);
double d1 = j * itm_elev[1];
- if ( (itm_elev[2] + transmitter_height) > (itm_elev[num_points_1st + 2] + clutter_height) ) {
+ if ( (itm_elev[2] + transmitter_height) > (itm_elev[num_points_1st + 1] + clutter_height) ) {
d1 = (num_points_1st - j) * itm_elev[1];
}
double ray_height = (grad * d1) + min_elev;
double intrusion = fabs(clearance);
//cerr << "Clutter:: clearance: " << clearance << endl;
if (clearance >= 0) {
- clutter_loss +=0.0;
+ // no losses
}
else if (clearance < 0 && (intrusion < clutter_height)) {
clutter_loss += clutter_density * (clutter_height / (frs_rad * 2 ) ) * freq/100;
}
else {
- clutter_loss += 0.0;
+ // no losses
}
j++;
- last = k+1;
+ mat++;
+ last = k;
}
/** and the second pass */
- int l =1;
- for (int k=last;k < num_points_2nd ;k++) {
+ int l =1; // first point is diffraction edge, 2nd the RX elevation
+ for (int k=last+1;k < num_points_2nd ;k++) {
double clutter_height = 0.0; // mean clutter height for a certain terrain type
double clutter_density = 0.0; // percent of reflected wave
- get_material_properties(materials[j-1], clutter_height, clutter_density);
- //cerr << "Clutter:: material: " << materials[j-1] << " height: " << clutter_height << ", density: " << clutter_density << endl;
- double grad = fabs(itm_elev[last] + clutter_height - itm_elev[(int)itm_elev[0] + 2] + receiver_height) / distance_m;
+ get_material_properties(materials[mat], clutter_height, clutter_density);
+ //cerr << "Clutter:: material: " << materials[mat] << " height: " << clutter_height << ", density: " << clutter_density << endl;
+ double grad = fabs(itm_elev[last] + clutter_height - itm_elev[(int)itm_elev[0] + 1] + receiver_height) / distance_m;
// First Fresnel radius
double frs_rad = 548 * sqrt( (l * itm_elev[1] * (num_points_2nd - l) * itm_elev[1] / 1000000) / ( num_points_2nd * itm_elev[1] * freq / 1000) );
//cerr << "Clutter:: fresnel radius: " << frs_rad << endl;
//double earth_h = distance_m * (distance_m - j * itm_elev[1]) / ( 1000000 * 12.75 * 1.33 ); // K=4/3
- double min_elev = SGMiscd::min(itm_elev[last] + clutter_height, itm_elev[(int)itm_elev[0] + 2] + receiver_height);
+ double min_elev = SGMiscd::min(itm_elev[last] + clutter_height, itm_elev[(int)itm_elev[0] + 1] + receiver_height);
double d1 = l * itm_elev[1];
- if ( (itm_elev[last] + clutter_height) > (itm_elev[(int)itm_elev[0] + 2] + receiver_height) ) {
+ if ( (itm_elev[last] + clutter_height) > (itm_elev[(int)itm_elev[0] + 1] + receiver_height) ) {
d1 = (num_points_2nd - l) * itm_elev[1];
}
double ray_height = (grad * d1) + min_elev;
double intrusion = fabs(clearance);
//cerr << "Clutter:: clearance: " << clearance << endl;
if (clearance >= 0) {
- clutter_loss +=0.0;
+ // no losses
}
else if (clearance < 0 && (intrusion < clutter_height)) {
clutter_loss += clutter_density * (clutter_height / (frs_rad * 2 ) ) * freq/100;
}
else {
- clutter_loss += 0.0;
+ // no losses
}
j++;
+ l++;
+ mat++;
}
}
else { // double horizon: same as single horizon, except there are 3 segments
+ int num_points_1st = (int)floor( horizons[0] * (double)itm_elev[0] / distance_m );
+ int num_points_2nd = (int)floor( (horizons[1] - horizons[0]) * (double)itm_elev[0] / distance_m );
+ int num_points_3rd = (int)floor( (distance_m - horizons[1]) * (double)itm_elev[0] / distance_m );
+ int last = 1;
+ /** perform the first pass */
+ int mat = 0;
+ int j=1; // first point is TX elevation, 2nd is obstruction elevation
+ for (int k=3;k < num_points_1st ;k++) {
+
+ double clutter_height = 0.0; // mean clutter height for a certain terrain type
+ double clutter_density = 0.0; // percent of reflected wave
+ get_material_properties(materials[mat], clutter_height, clutter_density);
+ //cerr << "Clutter:: material: " << materials[mat] << " height: " << clutter_height << ", density: " << clutter_density << endl;
+ double grad = fabs(itm_elev[2] + transmitter_height - itm_elev[num_points_1st + 1] + clutter_height) / distance_m;
+ // First Fresnel radius
+ double frs_rad = 548 * sqrt( (j * itm_elev[1] * (num_points_1st - j) * itm_elev[1] / 1000000) / ( num_points_1st * itm_elev[1] * freq / 1000) );
+
+ //cerr << "Clutter:: fresnel radius: " << frs_rad << endl;
+ //double earth_h = distance_m * (distance_m - j * itm_elev[1]) / ( 1000000 * 12.75 * 1.33 ); // K=4/3
+
+ double min_elev = SGMiscd::min(itm_elev[2] + transmitter_height, itm_elev[num_points_1st + 1] + clutter_height);
+ double d1 = j * itm_elev[1];
+ if ( (itm_elev[2] + transmitter_height) > (itm_elev[num_points_1st + 1] + clutter_height) ) {
+ d1 = (num_points_1st - j) * itm_elev[1];
+ }
+ double ray_height = (grad * d1) + min_elev;
+ //cerr << "Clutter:: ray height: " << ray_height << " ground height:" << itm_elev[k] << endl;
+ double clearance = ray_height - (itm_elev[k] + clutter_height) - frs_rad * 8/10;
+ double intrusion = fabs(clearance);
+ //cerr << "Clutter:: clearance: " << clearance << endl;
+ if (clearance >= 0) {
+ // no losses
+ }
+ else if (clearance < 0 && (intrusion < clutter_height)) {
+
+ clutter_loss += clutter_density * (intrusion / (frs_rad * 2) ) * freq/100;
+ }
+ else if (clearance < 0 && (intrusion > clutter_height)) {
+ clutter_loss += clutter_density * (clutter_height / (frs_rad * 2 ) ) * freq/100;
+ }
+ else {
+ // no losses
+ }
+ j++;
+ last = k;
+ }
+
+ /** and the second pass */
+
+ int l =1; // first point is 1st obstruction elevation, 2nd is 2nd obstruction elevation
+ for (int k=last;k < num_points_2nd ;k++) {
+
+ double clutter_height = 0.0; // mean clutter height for a certain terrain type
+ double clutter_density = 0.0; // percent of reflected wave
+ get_material_properties(materials[mat], clutter_height, clutter_density);
+ //cerr << "Clutter:: material: " << materials[mat] << " height: " << clutter_height << ", density: " << clutter_density << endl;
+ double grad = fabs(itm_elev[last] + clutter_height - itm_elev[num_points_1st + num_points_2nd + 1] + clutter_height) / distance_m;
+ // First Fresnel radius
+ double frs_rad = 548 * sqrt( (l * itm_elev[1] * (num_points_2nd - j) * itm_elev[1] / 1000000) / ( num_points_2nd * itm_elev[1] * freq / 1000) );
+
+ //cerr << "Clutter:: fresnel radius: " << frs_rad << endl;
+ //double earth_h = distance_m * (distance_m - j * itm_elev[1]) / ( 1000000 * 12.75 * 1.33 ); // K=4/3
+
+ double min_elev = SGMiscd::min(itm_elev[last] + clutter_height, itm_elev[num_points_1st + num_points_2nd + 2] + clutter_height);
+ double d1 = l * itm_elev[1];
+ if ( (itm_elev[last] + clutter_height) > (itm_elev[num_points_1st + num_points_2nd + 1] + clutter_height) ) {
+ d1 = (num_points_2nd - l) * itm_elev[1];
+ }
+ double ray_height = (grad * d1) + min_elev;
+ //cerr << "Clutter:: ray height: " << ray_height << " ground height:" << itm_elev[k] << endl;
+ double clearance = ray_height - (itm_elev[k] + clutter_height) - frs_rad * 8/10;
+ double intrusion = fabs(clearance);
+ //cerr << "Clutter:: clearance: " << clearance << endl;
+ if (clearance >= 0) {
+ // no losses
+ }
+ else if (clearance < 0 && (intrusion < clutter_height)) {
+
+ clutter_loss += clutter_density * (intrusion / (frs_rad * 2) ) * freq/100;
+ }
+ else if (clearance < 0 && (intrusion > clutter_height)) {
+ clutter_loss += clutter_density * (clutter_height / (frs_rad * 2 ) ) * freq/100;
+ }
+ else {
+ // no losses
+ }
+ j++;
+ l++;
+ mat++;
+ last = k;
+ }
+
+ /** third and final pass */
+
+ int m =1; // first point is 2nd obstruction elevation, 3rd is RX elevation
+ for (int k=last;k < num_points_3rd ;k++) {
+
+ double clutter_height = 0.0; // mean clutter height for a certain terrain type
+ double clutter_density = 0.0; // percent of reflected wave
+ get_material_properties(materials[mat], clutter_height, clutter_density);
+ //cerr << "Clutter:: material: " << materials[mat] << " height: " << clutter_height << ", density: " << clutter_density << endl;
+ double grad = fabs(itm_elev[last] + clutter_height - itm_elev[(int)itm_elev[0] + 1] + receiver_height) / distance_m;
+ // First Fresnel radius
+ double frs_rad = 548 * sqrt( (m * itm_elev[1] * (num_points_3rd - m) * itm_elev[1] / 1000000) / ( num_points_3rd * itm_elev[1] * freq / 1000) );
+
+ //cerr << "Clutter:: fresnel radius: " << frs_rad << endl;
+ //double earth_h = distance_m * (distance_m - j * itm_elev[1]) / ( 1000000 * 12.75 * 1.33 ); // K=4/3
+
+ double min_elev = SGMiscd::min(itm_elev[last] + clutter_height, itm_elev[(int)itm_elev[0] + 1] + receiver_height);
+ double d1 = m * itm_elev[1];
+ if ( (itm_elev[last] + clutter_height) > (itm_elev[(int)itm_elev[0] + 1] + receiver_height) ) {
+ d1 = (num_points_3rd - m) * itm_elev[1];
+ }
+ double ray_height = (grad * d1) + min_elev;
+ //cerr << "Clutter:: ray height: " << ray_height << " ground height:" << itm_elev[k] << endl;
+ double clearance = ray_height - (itm_elev[k] + clutter_height) - frs_rad * 8/10;
+ double intrusion = fabs(clearance);
+ //cerr << "Clutter:: clearance: " << clearance << endl;
+ if (clearance >= 0) {
+ // no losses
+ }
+ else if (clearance < 0 && (intrusion < clutter_height)) {
+
+ clutter_loss += clutter_density * (intrusion / (frs_rad * 2) ) * freq/100;
+ }
+ else if (clearance < 0 && (intrusion > clutter_height)) {
+ clutter_loss += clutter_density * (clutter_height / (frs_rad * 2 ) ) * freq/100;
+ }
+ else {
+ // no losses
+ }
+ j++;
+ m++;
+ mat++;
+ last = k+1;
+ }
+
}
}
- else if (p_mode == 2) { // troposcatter: use the first smooth earth horizon as mid point
-
+ else if (p_mode == 2) { // troposcatter: ignore ground clutter for now...
+ clutter_loss = 0.0;
}
}
-/*** Material properties database
+/*** Temporary material properties database
* height: median clutter height
* density: radiowave attenuation factor
***/
projects / flightgear.git / commitdiff