167 lines
4.3 KiB
C++
Executable File
167 lines
4.3 KiB
C++
Executable File
#include "Observer.h"
|
|
#include "SGP4.h"
|
|
|
|
#include <cmath>
|
|
#include <iostream>
|
|
|
|
Julian FindCrossingPoint(const CoordGeodetic& user_geo, SGP4& sgp4, const Julian& initial_time1, const Julian& initial_time2, bool finding_aos) {
|
|
|
|
Observer obs(user_geo);
|
|
Eci eci;
|
|
|
|
bool searching = true;
|
|
unsigned int loop_count = 0;
|
|
|
|
Julian time1 = initial_time1;
|
|
Julian time2 = initial_time2;
|
|
|
|
Julian middle_time = time1 + (time2.GetDate() - time1.GetDate()) / 2.0;
|
|
|
|
while (searching && loop_count < 25) {
|
|
|
|
/*
|
|
* find position
|
|
*/
|
|
sgp4.FindPosition(&eci, middle_time);
|
|
CoordTopographic topo = obs.GetLookAngle(eci);
|
|
|
|
if (topo.elevation > 0.0) {
|
|
|
|
if (finding_aos) {
|
|
time2 = middle_time;
|
|
} else {
|
|
time1 = middle_time;
|
|
}
|
|
} else {
|
|
|
|
if (finding_aos) {
|
|
time1 = middle_time;
|
|
} else {
|
|
time2 = middle_time;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* when two times are within a second, stop
|
|
*/
|
|
if (((time2.GetDate() - time1.GetDate()) * kSECONDS_PER_DAY) < 1.0) {
|
|
searching = false;
|
|
}
|
|
|
|
middle_time = time1 + (time2.GetDate() - time1.GetDate()) / 2.0;
|
|
loop_count++;
|
|
};
|
|
|
|
/*
|
|
* convert time to whole seconds
|
|
*/
|
|
if(finding_aos)
|
|
middle_time = floor(middle_time.GetDate() * kSECONDS_PER_DAY) / kSECONDS_PER_DAY;
|
|
else
|
|
middle_time = ceil(middle_time.GetDate() * kSECONDS_PER_DAY) / kSECONDS_PER_DAY;
|
|
|
|
return middle_time;
|
|
}
|
|
|
|
void AOSLOS(const CoordGeodetic& user_geo, SGP4& sgp4, const Julian& start_time, const Julian& end_time) {
|
|
|
|
Observer obs(user_geo);
|
|
Eci eci;
|
|
|
|
bool first_run = true;
|
|
Julian previous_time = start_time;
|
|
|
|
Julian aos_time;
|
|
Julian los_time;
|
|
bool found_aos = false;
|
|
bool found_los = false;
|
|
|
|
for (Julian current_time = start_time; current_time <= end_time; current_time.AddMin(1.0)) {
|
|
|
|
sgp4.FindPosition(&eci, current_time);
|
|
CoordTopographic topo = obs.GetLookAngle(eci);
|
|
|
|
if (topo.elevation > 0.0) {
|
|
/*
|
|
* satellite is above horizon
|
|
* and its the first run, so just use start_time
|
|
*/
|
|
if (first_run) {
|
|
|
|
aos_time = start_time;
|
|
found_aos = true;
|
|
found_los = false;
|
|
|
|
/*
|
|
* not the first iteration and satellite has
|
|
* gone above horizon, so find AOS
|
|
*/
|
|
} else if (!found_aos) {
|
|
|
|
aos_time = FindCrossingPoint(user_geo, sgp4, previous_time, current_time, true);
|
|
found_aos = true;
|
|
found_los = false;
|
|
}
|
|
} else {
|
|
/*
|
|
* if satellite now below horizon and have previously
|
|
* found AOS, find LOS
|
|
*/
|
|
if (found_aos) {
|
|
|
|
los_time = FindCrossingPoint(user_geo, sgp4, previous_time, current_time, false);
|
|
found_aos = false;
|
|
found_los = false;
|
|
std::cout << "AOS: " << aos_time << ", LOS: " << los_time << std::endl;
|
|
}
|
|
}
|
|
|
|
first_run = false;
|
|
previous_time = current_time;
|
|
}
|
|
|
|
/*
|
|
* is satellite still above horizon at end of search period
|
|
*/
|
|
if (found_aos && !found_los) {
|
|
|
|
los_time = end_time;
|
|
std::cout << "AOS: " << aos_time << ", LOS: " << los_time << std::endl;
|
|
}
|
|
}
|
|
|
|
int main() {
|
|
|
|
CoordGeodetic geo(51.37322, 0.089607, 0.05);
|
|
Tle tle("STS 134 ",
|
|
"1 37577U 11020A 11146.50425755 .00016213 00000-0 10821-3 0 213",
|
|
"2 37577 51.6484 271.9502 0003400 321.9646 127.1023 15.75523823 1551");
|
|
SGP4 sgp4(tle);
|
|
|
|
Julian start_date;
|
|
Julian end_date(start_date);
|
|
end_date.AddDay(10.0);
|
|
|
|
/*
|
|
* generate 10 day schedule
|
|
*/
|
|
AOSLOS(geo, sgp4, start_date, end_date);
|
|
|
|
return 0;
|
|
#if 0
|
|
Eci eci;
|
|
|
|
while (1) {
|
|
Julian now;
|
|
sgp4.FindPosition(&eci, now);
|
|
CoordTopographic topo = obs.GetLookAngle(eci);
|
|
CoordGeodetic geo = eci.ToGeodetic();
|
|
std::cout << now << " ";
|
|
std::cout << topo << " ";
|
|
std::cout << geo << std::endl;
|
|
};
|
|
|
|
return 0;
|
|
#endif
|
|
}
|