Improved sat tracker which takes pass into account.

console/console/console_sattracker.c

@@ -53,6 +53,8 @@
 #include "log.h"
 
 #define TIME_OFFSET 2
+#define EL_HORIZON -1.0
+#define NEXTPASS_RANGE_T (3600 * 24)
 
 char *command_host = "localhost";
 int command_port = CONSOLE_COMMAND_PORT;
@@ -69,6 +71,114 @@ char tle_str[139] =
 struct location *location;
 struct predict *predict = NULL;
 
+static bool passknown = false;
+static double az_aos = 0;
+static time_t t_los;
+
+void nextpass(struct predict *predict)
+{
+	time_t t, tnow = time(NULL);
+	double JD;
+	struct ln_date date;
+	int i;
+	double prev_az, az, el;
+	bool aos = false, los = false;
+	bool cross_west = false, cross_east = false;
+	int t_west_1 = 0, t_east_1 = 0, t_west_2 = 0, t_east_2 = 0;
+	
+	for (i = TIME_OFFSET; i < NEXTPASS_RANGE_T; i++) {
+		t = tnow + i;
+		ln_get_date_from_timet(&t, &date);
+		JD = ln_get_julian_day(&date);
+
+		predict_calc_azel(predict, JD, &az, &el);
+		
+		az -= 180.0;
+		
+		if (el >= EL_HORIZON && !aos) {
+			log_send(LOG_T_INFO, 
+			    "Next pass starts in %d seconds, az=%f", i, az);
+			printf( 
+			    "Next pass starts in %d seconds, az=%f\n", i, az);
+			aos = true;
+			prev_az = az;
+			az_aos = az;
+		}
+		if (el < EL_HORIZON && aos) {
+			log_send(LOG_T_INFO,
+			    "Next pass ends in %d seconds", i);
+			printf(
+			    "Next pass ends in %d seconds\n", i);
+			los = true;
+			t_los = tnow + i;
+			break;
+		}
+		
+		if (aos && !los) {
+			printf("az: %f\n", az);
+			/* this is a pass */
+			if (az < -90.0 && prev_az > 90.0) {
+				/* crossed north */
+				prev_az -= 360.0;
+			}
+			if (az > 90.0 && prev_az < -90.0) {
+				/* crossed north */
+				prev_az += 360.0;
+			}
+			if (az <= 90.0 && prev_az > 90.0)
+				cross_west = true;
+			if (az >= -90.0 && prev_az < -90.0)
+				cross_east = true;
+			if (cross_east) {
+				t_west_2++;
+			} else {
+				t_west_1++;
+			}
+			if (cross_west) {
+				t_east_2++;
+			} else {
+				t_east_1++;
+			}
+		}
+	}
+	log_send(LOG_T_INFO,
+	    "cross_west: %d, cross_east: %d, t_w_1: %d, t_w_2: %d, t_e_1: %d, t_e_2: %d",
+	    cross_west, cross_east, t_west_1, t_west_2, t_east_1, t_east_2);
+	printf(
+	    "cross_west: %d, cross_east: %d, t_w_1: %d, t_w_2: %d, t_e_1: %d, t_e_2: %d\n",
+	    cross_west, cross_east, t_west_1, t_west_2, t_east_1, t_east_2);
+	if (t_west_1 >= t_west_2 &&
+	    t_west_1 >= t_east_1 &&
+	    t_west_1 >= t_east_2) {
+		/* if we begin with start az we might go through east late */
+		if (az_aos < -90) {
+			az_aos += 360;
+		}
+	} else if (t_west_2 >= t_west_1 &&
+	    t_west_2 >= t_east_1 &&
+	    t_west_2 >= t_east_2) {
+		/* if we begin with start az we go through east in wrong way first */
+		az_aos += 360;
+	} else if (t_east_1 >= t_west_1 &&
+	    t_east_1 >= t_west_2 &&
+	    t_east_1 >= t_east_2) {
+		/* if we begin with start az we might go through west late */
+		if (az_aos > 90) {
+			az_aos -= 360;
+		}
+	} else {
+		az_aos -= 360;
+	}
+	
+	if (az_aos > 270.0)
+		az_aos = 270.0;
+	if (az_aos < -270.0)
+		az_aos = -270.0;
+
+	printf("new az_aos: %f\n", az_aos);
+	passknown = true;
+}
+
 bool set_tle(char newtle[139])
 {
 	double lat, lon, alt;
@@ -88,6 +198,7 @@ bool set_tle(char newtle[139])
 	if (predict)
 		predict_free(predict);
 	predict = predict_create(tle_str, lat, lon, alt);
+	nextpass(predict);
 	
 	log_send(LOG_T_INFO, "Switching to new TLE");
 	
@@ -236,13 +347,15 @@ int main(int argc, char **argv)
 	cmd_srv = command_server_create(cmd_port, 0, 100);
 	if (!cmd_srv) {
 		printf("Could not open listen port for commands\n");
+		return -1;
 	} else {
 		command_server_handler_set(cmd_srv, handle_cmd);
 	}
 
 	stat_srv = status_server_create(stat_port, 0, 100);
-	if (!cmd_srv) {
+	if (!stat_srv) {
 		printf("Could not open listen port for status\n");
+		return -1;
 	}
 
 	weather = weather_create("Dwingeloo");
@@ -274,6 +387,38 @@ int main(int argc, char **argv)
 
 			predict_calc_azel(predict, JD, &az, &el);
 
+			/* predict has an az range from 0 to 360 with 0 being South.
+			   Dwingeloo has an az range from -270 to 270 with 0 being South
+			 */
+			az -= 180.0;
+			
+			if (el < EL_HORIZON) {
+				if (!passknown)
+					nextpass(predict);
+				
+				/* large step? */
+				if (fabs(az_aos - az) > 180.0) {
+					printf("Preset to aos position %f -> %f\n", az, az_aos);
+					az += copysign(360.0, az_aos);
+				}
+			} else {
+				/* check if we might have to compensate 360 
+				   degrees to prevent large az steps
+				 */
+				printf("fabs(%f - %f): %f\n", last_az,az,fabs(last_az- az));
+				if (az > 90.0 || az < -90.0) {
+					/* large step? */
+					if (fabs(last_az - az) > 200.0) {
+						printf("Swapping AZ\n");
+						az += copysign(360.0, last_az);
+					}
+				}
+				passknown = false;
+			}
+			
+			if (t > t_los)
+				passknown = false;
+						
 			if (refraction_enable) {
 				/* Get current weather */
 				temperature = weather_get_temperature(weather);
@@ -284,11 +429,6 @@ int main(int argc, char **argv)
 				el += alt_adj;
 			}
 			
-			/* libnova has an az range from 0 to 360 with 0 being South.
-			   Dwingeloo has an az range from -270 to 270 with 0 being South
-			 */
-			az -= 180.0;
-			
 			if (dt_model_enable) {
 				double daz, del;
 				
@@ -299,18 +439,7 @@ int main(int argc, char **argv)
 				el += del;
 			}
 
-			/* check if we might have compensate 360 degrees to
-			   prevent large az steps
-			 */
-			printf("fabs(%f - %f): %f\n", last_az,az,fabs(last_az- az));
-			if (az > 90.0 || az < -90.0) {
-				/* large step? */
-				if (fabs(last_az - az) > 200.0) {
-					printf("Swapping AZ\n");
-					az += copysign(360.0, last_az);
-				}
-			}
-			if (!switch_cmd && fabs(last_az - az) > 180.0) {
+			if (!switch_cmd && fabs(last_az - az) > 90.0) {
 				if (switch_enabled)
 					log_send(LOG_T_WARNING,
 					    "Disabling tracker to prevent large azimuth jump");
@@ -319,6 +448,10 @@ int main(int argc, char **argv)
 
 			last_az = az;
 			
+			/* Temporary limit on elevation */
+			if (el < 0.0)
+				el = 0.0;
+			
 			printf("Setpoint: %d %f %f %f\n",
 			    (unsigned int)t, JD, az, el);