better handling stale tle

orekit can throw exception and crash application on startup
dernasherbrezon · Jul 21, 2024 · 0120e6b · 0120e6b
1 parent 468e977
commit 0120e6b
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Showing 3 changed files with 53 additions and 9 deletions.
diff --git a/src/main/java/ru/r2cloud/predict/MaxElevationHandler.java b/src/main/java/ru/r2cloud/predict/MaxElevationHandler.java
@@ -10,7 +10,7 @@
 public class MaxElevationHandler implements EventHandler<ElevationExtremumDetector> {
 
 	private AbsoluteDate date;
-	private double maxElevation;
+	private final double maxElevation;
 
 	public MaxElevationHandler(double maxElevation) {
 		this.maxElevation = maxElevation;

diff --git a/src/main/java/ru/r2cloud/predict/PredictOreKit.java b/src/main/java/ru/r2cloud/predict/PredictOreKit.java
@@ -145,7 +145,12 @@ private static List<SatPass> calculateFixedDirectional(AntennaConfiguration ante
 		EventsLogger logger = new EventsLogger();
 		tlePropagator.clearEventsDetectors();
 		tlePropagator.addEventDetector(logger.monitorDetector(detector));
-		tlePropagator.propagate(initialDate, new AbsoluteDate(initialDate, PREDICT_INTERVAL_SECONDS));
+		try {
+			tlePropagator.propagate(initialDate, new AbsoluteDate(initialDate, PREDICT_INTERVAL_SECONDS));
+		} catch (Exception e) {
+			LOG.error("unable to calculate schedule for {} date: {}", tlePropagator.getTLE().getSatelliteNumber(), initialDate, e);
+			return Collections.emptyList();
+		}
 		return convert(initialDate, logger.getLoggedEvents());
 	}
 
@@ -180,12 +185,13 @@ public Action eventOccurred(SpacecraftState s, ElevationExtremumDetector detecto
 		long initialMillis = initialDate.toDate(TimeScalesFactory.getUTC()).getTime();
 		for (AbsoluteDate curMax : max) {
 			SatPass cur = findStartEnd(tlePropagator, baseStationFrame, curMax, antenna);
-			if (cur != null) {
-				if (cur.getStartMillis() < initialMillis) {
-					cur.setStart(initialDate);
-				}
-				result.add(cur);
+			if (cur == null) {
+				continue;
+			}
+			if (cur.getStartMillis() < initialMillis) {
+				cur.setStart(initialDate);
 			}
+			result.add(cur);
 		}
 		return result;
 	}
@@ -195,7 +201,12 @@ private static SatPass calculateNextOmnidirectional(AntennaConfiguration antenna
 		ElevationExtremumDetector maxDetector = new ElevationExtremumDetector(600, 1, baseStationFrame).withMaxIter(48 * 60).withHandler(maxElevationHandler);
 		tlePropagator.clearEventsDetectors();
 		tlePropagator.addEventDetector(new EventSlopeFilter<EventDetector>(maxDetector, FilterType.TRIGGER_ONLY_DECREASING_EVENTS));
-		tlePropagator.propagate(initialDate, new AbsoluteDate(initialDate, PREDICT_INTERVAL_SECONDS));
+		try {
+			tlePropagator.propagate(initialDate, new AbsoluteDate(initialDate, PREDICT_INTERVAL_SECONDS));
+		} catch (Exception e) {
+			LOG.error("unable to calculate next observation. Most likely TLE is stale", e);
+			return null;
+		}
 		if (maxElevationHandler.getDate() == null) {
 			return null;
 		}
@@ -210,7 +221,12 @@ private static SatPass findStartEnd(TLEPropagator tlePropagator, TopocentricFram
 		tlePropagator.addEventDetector(boundsDetector);
 		// 60 mins before and 60 mins later
 		AbsoluteDate startDate = maxElevationTime.shiftedBy(-60 * 60.0);
-		tlePropagator.propagate(startDate, maxElevationTime.shiftedBy(60 * 60.0));
+		try {
+			tlePropagator.propagate(startDate, maxElevationTime.shiftedBy(60 * 60.0));
+		} catch (Exception e) {
+			LOG.error("unable to calculate start/end times. Most likely TLE is stale", e);
+			return null;
+		}
 
 		if (minElevationHandler.getStart() == null || minElevationHandler.getEnd() == null) {
 			return null;

diff --git a/src/test/java/ru/r2cloud/satellite/PredictOreKitTest.java b/src/test/java/ru/r2cloud/satellite/PredictOreKitTest.java
@@ -2,6 +2,7 @@
 
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertNull;
+import static org.junit.Assert.assertTrue;
 
 import java.text.SimpleDateFormat;
 import java.util.Date;
@@ -77,6 +78,30 @@ public void testFixedDirectionalAntenna() throws Exception {
 		assertPosition("00:29:32", "00:31:55", schedule.get(3));
 	}
 
+	@Test
+	public void testStaleTle() throws Exception {
+		config.setProperty("locaiton.lat", "51.82");
+		config.setProperty("locaiton.lon", "-0.05");
+		antenna.setMinElevation(2);
+		antenna.setGuaranteedElevation(10);
+		List<SatPass> result = predict.calculateSchedule(antenna, getDate("21-07-2024 14:07:37"), createPropagatorForStaleTle());
+		assertTrue(result.isEmpty());
+		assertNull(predict.calculateNext(antenna, getDate("21-07-2024 20:06:37"), createPropagatorForStaleTle()));
+	}
+
+	// it looks like Orekit has some state,
+	// calling new propagator with different dates
+	// cause different exceptions
+	@Test
+	public void testStaleTle2() throws Exception {
+		config.setProperty("locaiton.lat", "51.82");
+		config.setProperty("locaiton.lon", "-0.05");
+		antenna.setMinElevation(2);
+		antenna.setGuaranteedElevation(10);
+		predict.calculateSchedule(antenna, getDate("21-07-2024 00:06:37"), createPropagatorForStaleTle());
+		assertNull(predict.calculateNext(antenna, getDate("21-07-2024 20:06:37"), createPropagatorForStaleTle()));
+	}
+
 	private static Date getDate(String str) throws Exception {
 		SimpleDateFormat sdf = new SimpleDateFormat("dd-MM-yyyy HH:mm:ss");
 		sdf.setTimeZone(TimeZone.getTimeZone("Europe/London"));
@@ -105,4 +130,7 @@ public void start() throws Exception {
 		noaa15 = TLEPropagator.selectExtrapolator(new org.orekit.propagation.analytical.tle.TLE("1 25338U 98030A   17271.51297398  .00000037  00000-0  34305-4 0  9992", "2 25338  98.7817 282.6269 0009465 266.6019  93.4077 14.25818111  7720"));
 	}
 
+	private static TLEPropagator createPropagatorForStaleTle() {
+		return TLEPropagator.selectExtrapolator(new org.orekit.propagation.analytical.tle.TLE("1 53377U 22096H   24154.02726409  .00833254  34873-3  13426-2 0  9991", "2 53377  97.3798  75.4551 0009283 160.8570 199.3061 16.03510163102082"));
+	}
 }