PredicThirteen::geodetic_t PredicThirteen::calc(PredicThirteen::tle_t t){ printTle(&t); DEBUG_PRINTLN("----------------------------------------"); PredicThirteen::vector_t zero_vector={0,0,0,0}; PredicThirteen::vector_t pos = zero_vector; PredicThirteen::vector_t vel = zero_vector; PredicThirteen::geodetic_t geo = {0,0,0,0}; jul_utc = daynum +723244000000LL; jul_epoch=Julian_Date_of_Epoch(t.epoch_year, t.epoch_day); printUint64("TestNum", (uint64_t) 11118562939LL); printUint64("daynum", daynum); printUint64("jul_utc",jul_utc); printUint64("jul_epoch",jul_epoch); tsince = ((jul_utc - jul_epoch)/1000000.0) * minday; select_ephemeris(&t); SGP4(tsince, &t, &pos, &vel); Convert_Sat_State(&pos, &vel); Magnitude(&vel); printVar("jul_utc", jul_utc); Calculate_LatLonAlt(jul_utc, &pos, &geo); printVector(&pos); printVector(&vel); printGeo(&geo); LAT = geo.lat; LON = geo.lon; Serial.print("LAT: "); Serial.println(LAT); Serial.print("LON: "); Serial.println(LON); return geo; }
/** \brief SGP4SDP4 driver for doing AOS/LOS calculations. * \param sat Pointer to the satellite data. * \param qth Pointer to the QTH data. * \param t The time for calculation (Julian Date) * */ void predict_calc (sat_t *sat, qth_t *qth, gdouble t) { obs_set_t obs_set; geodetic_t sat_geodetic; geodetic_t obs_geodetic; double age; obs_geodetic.lon = qth->lon * de2ra; obs_geodetic.lat = qth->lat * de2ra; obs_geodetic.alt = qth->alt / 1000.0; obs_geodetic.theta = 0; sat->jul_utc = t; sat->tsince = (sat->jul_utc - sat->jul_epoch) * xmnpda; /* call the norad routines according to the deep-space flag */ if (sat->flags & DEEP_SPACE_EPHEM_FLAG) SDP4 (sat, sat->tsince); else SGP4 (sat, sat->tsince); Convert_Sat_State (&sat->pos, &sat->vel); /* get the velocity of the satellite */ Magnitude (&sat->vel); sat->velo = sat->vel.w; Calculate_Obs (sat->jul_utc, &sat->pos, &sat->vel, &obs_geodetic, &obs_set); Calculate_LatLonAlt (sat->jul_utc, &sat->pos, &sat_geodetic); while (sat_geodetic.lon < -pi) sat_geodetic.lon += twopi; while (sat_geodetic.lon > (pi)) sat_geodetic.lon -= twopi; sat->az = Degrees (obs_set.az); sat->el = Degrees (obs_set.el); sat->range = obs_set.range; sat->range_rate = obs_set.range_rate; sat->ssplat = Degrees (sat_geodetic.lat); sat->ssplon = Degrees (sat_geodetic.lon); sat->alt = sat_geodetic.alt; sat->ma = Degrees (sat->phase); sat->ma *= 256.0/360.0; sat->phase = Degrees (sat->phase); /* same formulas, but the one from predict is nicer */ //sat->footprint = 2.0 * xkmper * acos (xkmper/sat->pos.w); sat->footprint = 12756.33 * acos (xkmper / (xkmper+sat->alt)); age = sat->jul_utc - sat->jul_epoch; sat->orbit = (long) floor((sat->tle.xno * xmnpda/twopi + age * sat->tle.bstar * ae) * age + sat->tle.xmo/twopi) + sat->tle.revnum - 1; }
/** \brief Initialise satellite data. * \param sat The satellite to initialise. * \param qth Optional QTH info, use (0,0) if NULL. * * This function calculates the satellite data at t = 0, ie. epoch time * The function is called automatically by gtk_sat_data_read_sat. */ void gtk_sat_data_init_sat (sat_t *sat, qth_t *qth) { geodetic_t obs_geodetic; obs_set_t obs_set; geodetic_t sat_geodetic; double jul_utc, age; g_return_if_fail (sat != NULL); jul_utc = Julian_Date_of_Epoch (sat->tle.epoch); // => tsince = 0.0 sat->jul_epoch = jul_utc; /* initialise observer location */ if (qth != NULL) { obs_geodetic.lon = qth->lon * de2ra; obs_geodetic.lat = qth->lat * de2ra; obs_geodetic.alt = qth->alt / 1000.0; obs_geodetic.theta = 0; } else { obs_geodetic.lon = 0.0; obs_geodetic.lat = 0.0; obs_geodetic.alt = 0.0; obs_geodetic.theta = 0; } /* execute computations */ if (sat->flags & DEEP_SPACE_EPHEM_FLAG) SDP4 (sat, 0.0); else SGP4 (sat, 0.0); /* scale position and velocity to km and km/sec */ Convert_Sat_State (&sat->pos, &sat->vel); /* get the velocity of the satellite */ Magnitude (&sat->vel); sat->velo = sat->vel.w; Calculate_Obs (jul_utc, &sat->pos, &sat->vel, &obs_geodetic, &obs_set); Calculate_LatLonAlt (jul_utc, &sat->pos, &sat_geodetic); while (sat_geodetic.lon < -pi) sat_geodetic.lon += twopi; while (sat_geodetic.lon > (pi)) sat_geodetic.lon -= twopi; sat->az = Degrees (obs_set.az); sat->el = Degrees (obs_set.el); sat->range = obs_set.range; sat->range_rate = obs_set.range_rate; sat->ssplat = Degrees (sat_geodetic.lat); sat->ssplon = Degrees (sat_geodetic.lon); sat->alt = sat_geodetic.alt; sat->ma = Degrees (sat->phase); sat->ma *= 256.0/360.0; sat->footprint = 2.0 * xkmper * acos (xkmper/sat->pos.w); age = 0.0; sat->orbit = (long) floor((sat->tle.xno * xmnpda/twopi + age * sat->tle.bstar * ae) * age + sat->tle.xmo/twopi) + sat->tle.revnum - 1; /* orbit type */ sat->otype = get_orbit_type (sat); }
/* Main program */ int main(void) { /* TLE source file */ char tle_file[] = "./rax.txt"; /* Observer's geodetic co-ordinates. */ /* Lat North, Lon East in rads, Alt in km */ geodetic_t obs_geodetic = {0.7368, -1.4615, 0.251, 0.0}; /* Two-line Orbital Elements for the satellite */ tle_t tle ; /* Zero vector for initializations */ vector_t zero_vector = {0,0,0,0}; /* Satellite position and velocity vectors */ vector_t vel = zero_vector; vector_t pos = zero_vector; /* Satellite Az, El, Range, Range rate */ vector_t obs_set; /* Solar ECI position vector */ vector_t solar_vector = zero_vector; /* Solar observed azi and ele vector */ vector_t solar_set; /* Calendar date and time (UTC) */ struct tm utc; /* Satellite's predicted geodetic position */ geodetic_t sat_geodetic; double tsince, /* Time since epoch (in minutes) */ jul_epoch, /* Julian date of epoch */ jul_utc, /* Julian UTC date */ eclipse_depth = 0, /* Depth of satellite eclipse */ /* Satellite's observed position, range, range rate */ sat_azi, sat_ele, sat_range, sat_range_rate, /* Satellites geodetic position and velocity */ sat_lat, sat_lon, sat_alt, sat_vel, /* Solar azimuth and elevation */ sun_azi, sun_ele; /* Used for storing function return codes */ int flg; char ephem[5], /* Ephemeris in use string */ sat_status[12]; /* Satellite eclipse status */ /* Input one (first!) TLE set from file */ flg = Input_Tle_Set(tle_file, &tle); /* Abort if file open fails */ if( flg == -1 ) { printf(" File open failed - Exiting!\n"); exit(-1); } /* Print satellite name and TLE read status */ printf(" %s: ", tle.sat_name); if( flg == -2 ) { printf("TLE set bad - Exiting!\n"); exit(-2); } else printf("TLE set good - Happy Tracking!\n"); /* Printout of tle set data for tests if needed */ /* printf("\n %s %s %i %i %i\n" " %14f %10f %8f %8f\n" " %8f %8f %9f %8f %8f %12f\n", tle.sat_name, tle.idesg, tle.catnr, tle.elset, tle.revnum, tle.epoch, tle.xndt2o, tle.xndd6o, tle.bstar, tle.xincl, tle.xnodeo, tle.eo, tle.omegao, tle.xmo, tle.xno); */ /** !Clear all flags! **/ /* Before calling a different ephemeris */ /* or changing the TLE set, flow control */ /* flags must be cleared in main(). */ ClearFlag(ALL_FLAGS); /** Select ephemeris type **/ /* Will set or clear the DEEP_SPACE_EPHEM_FLAG */ /* depending on the TLE parameters of the satellite. */ /* It will also pre-process tle members for the */ /* ephemeris functions SGP4 or SDP4 so this function */ /* must be called each time a new tle set is used */ select_ephemeris(&tle); do /* Loop */ { /* Get UTC calendar and convert to Julian */ UTC_Calendar_Now(&utc); jul_utc = Julian_Date(&utc); /* Convert satellite's epoch time to Julian */ /* and calculate time since epoch in minutes */ jul_epoch = Julian_Date_of_Epoch(tle.epoch); tsince = (jul_utc - jul_epoch) * xmnpda; /* Copy the ephemeris type in use to ephem string */ if( isFlagSet(DEEP_SPACE_EPHEM_FLAG) ) strcpy(ephem,"SDP4"); else strcpy(ephem,"SGP4"); /* Call NORAD routines according to deep-space flag */ if( isFlagSet(DEEP_SPACE_EPHEM_FLAG) ) SDP4(tsince, &tle, &pos, &vel); else SGP4(tsince, &tle, &pos, &vel); /* Scale position and velocity vectors to km and km/sec */ Convert_Sat_State( &pos, &vel ); /* Calculate velocity of satellite */ Magnitude( &vel ); sat_vel = vel.w; /** All angles in rads. Distance in km. Velocity in km/s **/ /* Calculate satellite Azi, Ele, Range and Range-rate */ Calculate_Obs(jul_utc, &pos, &vel, &obs_geodetic, &obs_set); /* Calculate satellite Lat North, Lon East and Alt. */ Calculate_LatLonAlt(jul_utc, &pos, &sat_geodetic); /* Calculate solar position and satellite eclipse depth */ /* Also set or clear the satellite eclipsed flag accordingly */ Calculate_Solar_Position(jul_utc, &solar_vector); Calculate_Obs(jul_utc,&solar_vector,&zero_vector,&obs_geodetic,&solar_set); if( Sat_Eclipsed(&pos, &solar_vector, &eclipse_depth) ) SetFlag( SAT_ECLIPSED_FLAG ); else ClearFlag( SAT_ECLIPSED_FLAG ); /* Copy a satellite eclipse status string in sat_status */ if( isFlagSet( SAT_ECLIPSED_FLAG ) ) strcpy( sat_status, "Eclipsed" ); else strcpy( sat_status, "In Sunlight" ); /* Convert and print satellite and solar data */ sat_azi = Degrees(obs_set.x); sat_ele = Degrees(obs_set.y); sat_range = obs_set.z; sat_range_rate = obs_set.w; sat_lat = Degrees(sat_geodetic.lat); sat_lon = Degrees(sat_geodetic.lon); sat_alt = sat_geodetic.alt; sun_azi = Degrees(solar_set.x); sun_ele = Degrees(solar_set.y); printf("\n Date: %02d/%02d/%04d UTC: %02d:%02d:%02d Ephemeris: %s" "\n Azi=%6.1f Ele=%6.1f Range=%8.1f Range Rate=%6.2f" "\n Lat=%6.1f Lon=%6.1f Alt=%8.1f Vel=%8.3f" "\n Stellite Status: %s - Depth: %2.3f" "\n Sun Azi=%6.1f Sun Ele=%6.1f\n", utc.tm_mday, utc.tm_mon, utc.tm_year, utc.tm_hour, utc.tm_min, utc.tm_sec, ephem, sat_azi, sat_ele, sat_range, sat_range_rate, sat_lat, sat_lon, sat_alt, sat_vel, sat_status, eclipse_depth, sun_azi, sun_ele); sleep(1); } /* End of do */ while( 1 ); /* This stops Compaq ccc 'unreachcode' warning! */ return(0); } /* End of main() */
/* This is the old Calc() function. */ int predict_orbit(const predict_orbital_elements_t *orbital_elements, struct predict_orbit *m, double utc) { /* Set time to now if now time is provided: */ if (utc == 0) utc = predict_to_julian(time(NULL)); /* Satellite position and velocity vectors */ vec3_set(m->position, 0, 0, 0); vec3_set(m->velocity, 0, 0, 0); m->time = utc; double julTime = utc + 2444238.5; /* Convert satellite's epoch time to Julian */ /* and calculate time since epoch in minutes */ double epoch = 1000.0*orbital_elements->epoch_year + orbital_elements->epoch_day; double jul_epoch = Julian_Date_of_Epoch(epoch); double tsince = (julTime - jul_epoch)*xmnpda; /* Call NORAD routines according to deep-space flag. */ struct model_output output; switch (orbital_elements->ephemeris) { case EPHEMERIS_SDP4: sdp4_predict((struct _sdp4*)orbital_elements->ephemeris_data, tsince, &output); break; case EPHEMERIS_SGP4: sgp4_predict((struct _sgp4*)orbital_elements->ephemeris_data, tsince, &output); break; default: //Panic! return -1; } m->position[0] = output.pos[0]; m->position[1] = output.pos[1]; m->position[2] = output.pos[2]; m->velocity[0] = output.vel[0]; m->velocity[1] = output.vel[1]; m->velocity[2] = output.vel[2]; m->phase = output.phase; m->argument_of_perigee = output.omgadf; m->inclination = output.xinck; m->right_ascension = output.xnodek; /* TODO: Remove? Scale position and velocity vectors to km and km/sec */ Convert_Sat_State(m->position, m->velocity); /* Calculate satellite Lat North, Lon East and Alt. */ geodetic_t sat_geodetic; Calculate_LatLonAlt(utc, m->position, &sat_geodetic); m->latitude = sat_geodetic.lat; m->longitude = sat_geodetic.lon; m->altitude = sat_geodetic.alt; // Calculate solar position double solar_vector[3]; sun_predict(m->time, solar_vector); // Find eclipse depth and if sat is eclipsed m->eclipsed = is_eclipsed(m->position, solar_vector, &m->eclipse_depth); // Calculate footprint m->footprint = 2.0*xkmper*acos(xkmper/(xkmper + m->altitude)); // Calculate current number of revolutions around Earth double temp = twopi/xmnpda/xmnpda; double age = julTime - jul_epoch; double xno = orbital_elements->mean_motion*temp*xmnpda; double xmo = orbital_elements->mean_anomaly * M_PI / 180.0; m->revolutions = (long)floor((xno*xmnpda/(M_PI*2.0) + age*orbital_elements->bstar_drag_term)*age + xmo/(2.0*M_PI)) + orbital_elements->revolutions_at_epoch; //calculate whether orbit is decayed m->decayed = predict_decayed(orbital_elements, utc); return 0; }