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Added max elevation calculation

feature/19
Daniel Warner 2011-06-08 15:21:33 +00:00
parent ed47037ad4
commit a53f06ebbf
1 changed files with 90 additions and 30 deletions
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120
PassPredict.cpp
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@ -4,6 +4,82 @@
#include <cmath>
#include <iostream>
double FindMaxElevation(const CoordGeodetic& user_geo, SGP4& sgp4, const Julian& aos, const Julian& los) {
Observer obs(user_geo);
Eci eci;
double max_elevation = -99.9;
/*
* time step in seconds
*/
double time_step = 180.0;
/*
* still searching for max elevation
*/
bool searching = true;
/*
* fine tune the max elevation value
*/
bool fine_tune = false;
Julian current_time = aos;
while (current_time < los && searching) {
/*
* find position
*/
sgp4.FindPosition(&eci, current_time);
CoordTopographic topo = obs.GetLookAngle(eci);
/*
* keep updating max elevation
*/
if (topo.elevation > max_elevation) {
max_elevation = topo.elevation;
} else if (!fine_tune) {
/*
* passed max elevation
* max elevation happened in the last 6 minutes
* go back and fine tune max elevation value
*/
current_time.AddSec(-2.0 * time_step);
/*
* dont go back before aos
*/
if (current_time < aos)
current_time = aos;
/*
* 1 second increment
*/
time_step = 1.0;
fine_tune = true;
/*
* reset elevation
*/
max_elevation = -99.9;
} else {
/*
* found max elevation
*/
searching = false;
}
if (searching) {
current_time.AddSec(time_step);
if (current_time > los)
current_time = los;
}
};
return max_elevation;
}
Julian FindCrossingPoint(const CoordGeodetic& user_geo, SGP4& sgp4, const Julian& initial_time1, const Julian& initial_time2, bool finding_aos) {
Observer obs(user_geo);
@ -68,7 +144,8 @@ void AOSLOS(const CoordGeodetic& user_geo, SGP4& sgp4, const Julian& start_time,
bool found_aos = false;
bool found_los = false;
for (Julian current_time = start_time; current_time <= end_time; current_time.AddMin(1.0)) {
Julian current_time = start_time;
while (current_time < end_time) {
sgp4.FindPosition(&eci, current_time);
CoordTopographic topo = obs.GetLookAngle(eci);
@ -104,13 +181,18 @@ void AOSLOS(const CoordGeodetic& user_geo, SGP4& sgp4, const Julian& start_time,
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;
double max_elevation = FindMaxElevation(user_geo, sgp4, aos_time, los_time);
std::cout << "AOS: " << aos_time << ", LOS: " << los_time << ", Max El: " << RadiansToDegrees(max_elevation) << std::endl;
}
}
first_run = false;
previous_time = current_time;
}
current_time.AddMin(1.0);
if (current_time > end_time)
current_time = end_time;
};
/*
* is satellite still above horizon at end of search period
@ -118,16 +200,17 @@ void AOSLOS(const CoordGeodetic& user_geo, SGP4& sgp4, const Julian& start_time,
if (found_aos && !found_los) {
los_time = end_time;
std::cout << "AOS: " << aos_time << ", LOS: " << los_time << std::endl;
double max_elevation = FindMaxElevation(user_geo, sgp4, aos_time, los_time);
std::cout << "AOS: " << aos_time << ", LOS: " << los_time << ", Max El: " << RadiansToDegrees(max_elevation) << 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");
Tle tle("GIOVE-B ",
"1 32781U 08020A 11158.03814084 .00000088 00000-0 10000-3 0 4620",
"2 32781 55.9142 172.9458 0022365 228.3743 131.4697 1.70953903 19437");
SGP4 sgp4(tle);
Julian start_date;
@ -139,28 +222,5 @@ int main() {
*/
AOSLOS(geo, sgp4, start_date, end_date);
/*
* 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 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
}