Satellite Observers Workbench. NOT yet complete, just published for forum posters to \"cherry pick\" pieces of code as requiered as an example.
satapi/satapi.c
- Committer:
- AjK
- Date:
- 2010-10-11
- Revision:
- 0:0a841b89d614
File content as of revision 0:0a841b89d614:
/**************************************************************************** * Copyright 2010 Andy Kirkham, Stellar Technologies Ltd * * This file is part of the Satellite Observers Workbench (SOWB). * * SOWB 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 * (at your option) any later version. * * SOWB 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 SOWB. If not, see <http://www.gnu.org/licenses/>. * * $Id: main.cpp 5 2010-07-12 20:51:11Z ajk $ * ***************************************************************************/ #include "sowb.h" #include "user.h" #include "satapi.h" #include "utils.h" #include "debug.h" #include "gpio.h" #include "osd.h" #include "nexstar.h" #include "utils.h" #ifndef M_PI #define M_PI 3.1415926535898 #endif #define SCAN_INTERVAL 60 double satapi_aos(SAT_POS_DATA *q, bool goto_aos) { double tsince; char temp1[32], temp2[32]; strcpy(q->elements[0], "Lacrosse 2"); strcpy(q->elements[1], "1 21147U 91017A 10269.82093092 0.00000020 00000-0 28786-5 0 05"); strcpy(q->elements[2], "2 21147 67.9820 220.2995 0002000 244.7811 115.2189 14.76261286 07"); observer_now(q); P22_ASSERT; for (q->tsince = 0; q->tsince < (SCAN_INTERVAL * 90); q->tsince += SCAN_INTERVAL) { KICK_WATCHDOG; /* We are busy! */ satallite_calculate(q); if (q->elevation >= 10.) { /* Above horizon viewing. Work back to AOS. */ for (tsince = q->tsince, q->tsince--; q->elevation > 10. ; tsince = q->tsince--) { satallite_calculate(q); if (q->elevation < 10.) { //sprintf(temp, "%03f Q AOS El:%.1f AZ:%.1f %dKm\r\n", q->tsince, q->elevation, q->azimuth, (int)q->range); //debug_printf(temp); q->tsince = tsince; satallite_calculate(q); sprintf(temp1, "%03f T AOS El:%.1f AZ:%.1f %dKm\r\n", q->tsince, q->elevation, q->azimuth, (int)q->range); debug_printf(temp1); P22_DEASSERT; if (goto_aos) { sprintf(temp1, "%s T-%.2f", q->elements[0], tsince); osd_string_xy(1, 12, temp1); sprintf(temp1, "AOS %.2f%c %s%c %dKm", q->elevation, 176, printDouble_3_2(temp2, q->azimuth), 176, (int)q->range); osd_string_xy(1, 13, temp1); _nexstar_goto((uint32_t)((q->elevation / 360.) * 65536), (uint32_t)((q->azimuth / 360.) * 65536)); } return tsince; } } } } P22_DEASSERT; return 0.; } int satallite_calculate(SAT_POS_DATA *q) { double tsince; /* Ensure the time and place are valid. */ if (!q->time.is_valid) return -1; if (!q->location.is_valid) return -2; ClearFlag(ALL_FLAGS); Get_Next_Tle_Set(q->elements, &q->tle); select_ephemeris(&q->tle); q->jd_utc = gps_julian_date(&q->time); q->jd_epoch = Julian_Date_of_Epoch(q->tle.epoch); tsince = ((q->jd_utc + (q->tsince * (1 / 86400.))) - q->jd_epoch) * xmnpda; if (isFlagSet(DEEP_SPACE_EPHEM_FLAG)) { SDP4(tsince, &q->tle, &q->pos, &q->vel, &q->phase); } else { SGP4(tsince, &q->tle, &q->pos, &q->vel, &q->phase); } Convert_Sat_State(&q->pos, &q->vel); SgpMagnitude(&q->vel); // scalar magnitude, not brightness... q->velocity = q->vel.w; /* Populate the geodetic_t struct from data supplied. */ q->observer.lat = q->location.latitude * de2ra; q->observer.lon = q->location.longitude * de2ra; q->observer.alt = q->location.height / 1000.; if (q->location.north_south == 'S') q->observer.lat *= -1.; if (q->location.east_west == 'W') q->observer.lon *= -1.; Calculate_Obs(q->jd_utc, &q->pos, &q->vel, &q->observer, &q->obs_set); Calculate_LatLonAlt(q->jd_utc, &q->pos, &q->sat_geodetic); q->azimuth = Degrees(q->obs_set.x); q->elevation = Degrees(q->obs_set.y); q->range = q->obs_set.z; q->rangeRate = q->obs_set.w; q->height = q->sat_geodetic.alt; return 0; } /** observer_now * * Fills the data structure with the observers time and position. * * @param SAT_POS_DATA * A pointer to the data structure. */ SAT_POS_DATA * observer_now(SAT_POS_DATA *q) { gps_get_time(&q->time); gps_get_location_average(&q->location); return q; } AltAz * radec2altaz(double siderealDegrees, GPS_LOCATION_AVERAGE *location, RaDec *radec, AltAz *altaz) { double HA, DEC, LAT, mul, altitude, azimuth; mul = location->north_south == 'S' ? -1.0 : 1.0; /* Convert to radians. */ HA = siderealDegrees * (M_PI / 180.0) - (radec->ra * (M_PI / 180)); DEC = radec->dec * (M_PI / 180.0); LAT = (location->latitude * mul) * (M_PI / 180.0); altitude = atan2(- sin(HA) * cos(DEC), cos(LAT) * sin(DEC) - sin(LAT) * cos(DEC) * cos(HA)); azimuth = asin(sin(LAT) * sin(DEC) + cos(LAT) * cos(DEC) * cos(HA)); // Convert to degrees and swing azimuth around if needed. altaz->alt = azimuth * 180.0 / M_PI; altaz->azm = altitude * 180.0 / M_PI; if (altaz->azm < 0) altaz->azm += 360.0; return altaz; } RaDec * altaz2radec(double siderealDegrees, GPS_LOCATION_AVERAGE *location, AltAz *altaz, RaDec *radec) { double ALT, AZM, LAT, HA, DEC, mul; mul = location->north_south == 'S' ? -1.0 : 1.0; /* Convert to radians. */ LAT = (location->latitude * mul) * (M_PI / 180.0); ALT = altaz->alt * (M_PI / 180.0); AZM = altaz->azm * (M_PI / 180.0); /* Calculate the declination. */ DEC = asin( ( sin(ALT) * sin(LAT) ) + ( cos(ALT) * cos(LAT) * cos(AZM) ) ); radec->dec = DEC * 180.0 / M_PI; while (radec->dec < 0.0) radec->dec += 360.0; while (radec->dec > 360.0) radec->dec -= 360.0; /* Calculate the hour angle. */ HA = ( acos((sin(ALT) - sin(LAT) * sin(DEC)) / (cos(LAT) * cos(DEC)))) * 180.0 / M_PI; if (sin(AZM) > 0.0) HA = 360.0 - HA; /* Correct the HA for our sidereal time. */ HA = (siderealDegrees / 360.0 * 24.0) - (HA / 15.0); if (HA < 0.0) HA += 24.0; /* Convert the HA into degrees for the return. */ radec->ra = HA / 24.0 * 360.0; return radec; }