Add support for Signal ID to GSV Parser

resolves ktuukkangh-116

Author: ghillert

src/main/java/net/sf/marineapi/nmea/parser/GSVParser.java

@@ -1,6 +1,6 @@
 /*
  * GSVParser.java
- * Copyright (C) 2010 Kimmo Tuukkanen
+ * Copyright (C) 2010-2020 Kimmo Tuukkanen
  *
  * This file is part of Java Marine API.
  * <http://ktuukkan.github.io/marine-api/>
@@ -32,6 +32,7 @@
  * GSV sentence parser.
  *
  * @author Kimmo Tuukkanen
+ * @author Gunnar Hillert
  */
 class GSVParser extends SentenceParser implements GSVSentence {
 
@@ -40,8 +41,17 @@ class GSVParser extends SentenceParser implements GSVSentence {
     private static final int SENTENCE_NUMBER = 1;
     private static final int SATELLITES_IN_VIEW = 2;
 
+    // Satellite Group Start Index
+    private static final int SATELLITE_GROUP_START_INDEX = 3;
+
+    // Each Satellite Group has 4 values
+    private static final int SATELLITE_GROUP_SIZE = 4;
+
+    // A GSV Sentence may contain up to 4 satellites
+    private static final int SATELLITE_GROUP_MAX_NUMBER_OF_SATELLITES = 4;
+
     // satellite id fields
-    private static final int[] ID_FIELDS = {3, 7, 11, 15};
+    private static final int[] ID_FIELDS = {SATELLITE_GROUP_START_INDEX, 7, 11, 15};
 
     // satellite data fields, relative to each id field
     private static final int ELEVATION = 1;
@@ -74,6 +84,22 @@ public int getSatelliteCount() {
         return getIntValue(SATELLITES_IN_VIEW);
     }
 
+    /**
+     * @see net.sf.marineapi.nmea.sentence.GSVSentence#getSignalId()
+     */
+    @Override
+    public int getSignalId() {
+        final int signalIdIndex;
+        if (!this.isLast()) {
+        	signalIdIndex = SATELLITE_GROUP_START_INDEX + SATELLITE_GROUP_MAX_NUMBER_OF_SATELLITES * SATELLITE_GROUP_SIZE;
+        }
+        else {
+            int numberOfSatellites = this.getSatelliteCount() - ((this.getSentenceIndex() - 1) * SATELLITE_GROUP_SIZE);
+            signalIdIndex = SATELLITE_GROUP_START_INDEX + (SATELLITE_GROUP_SIZE * numberOfSatellites);
+        }
+        return getIntValue(signalIdIndex);
+    }
+
     /*
      * (non-Javadoc)
      * @see net.sf.marineapi.nmea.sentence.GSVSentence#getSatelliteInfo()

src/main/java/net/sf/marineapi/nmea/sentence/GSVSentence.java

@@ -1,20 +1,20 @@
-/* 
+/*
  * GSVSentence.java
  * Copyright (C) 2010 Kimmo Tuukkanen
- * 
+ *
  * This file is part of Java Marine API.
  * <http://ktuukkan.github.io/marine-api/>
- * 
+ *
  * Java Marine API is free software: you can redistribute it and/or modify it
  * under the terms of the GNU Lesser General Public License as published by the
  * Free Software Foundation, either version 3 of the License, or (at your
  * option) any later version.
- * 
+ *
  * Java Marine API 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 Lesser General Public License
  * for more details.
- * 
+ *
  * You should have received a copy of the GNU Lesser General Public License
  * along with Java Marine API. If not, see <http://www.gnu.org/licenses/>.
  */
@@ -35,42 +35,77 @@
  * <p>
  * Example: <br>
  * {@code $GPGSV,3,2,12,15,56,182,51,17,38,163,47,18,63,058,50,21,53,329,47*73}
- * 
+ *
  * @author Kimmo Tuukkanen
  */
 public interface GSVSentence extends Sentence {
 
 	/**
 	 * Get the number of satellites in view.
-	 * 
+	 *
 	 * @return Satellite count
 	 */
 	int getSatelliteCount();
 
 	/**
 	 * Get the satellites information.
-	 * 
+	 *
 	 * @return List of SatelliteInfo objects.
 	 */
 	List<SatelliteInfo> getSatelliteInfo();
 
 	/**
 	 * Get the total number of sentences in GSV sequence.
-	 * 
+	 *
 	 * @return Number of sentences
 	 */
 	int getSentenceCount();
 
+	/**
+	 * Get the GNSS signal ID (only NMEA 4.10 and later).
+	 * <p>
+	 * Be aware, that the returned signal id may differ between NMEA versions. For
+	 * example, in the NMEA protocol version 4.10 the BeiDou and QZSS signal IDs
+	 * are not defined. Therefore u-blox devices, for example, will send a proprietary
+	 * signal id value that differs from the one defined in NMEA Protocol 4.11.
+	 *
+	 * NMEA Protocol 4.11 defines the following signal ids:
+	 *
+	 * <ul>
+	 *   <li>GPS L1C/A = 1
+	 *   <li>GPS L2 CL = 6
+	 *   <li>GPS L2 CM = 5
+	 *   <li>SBAS L1C/A = 1
+	 *   <li>Galileo E1 C = 7
+	 *   <li>Galileo E1 B = 7
+	 *   <li>Galileo E5 bI = 2
+	 *   <li>Galileo E5 bQ = 2
+	 *   <li>BeiDou B1I D1 = 1
+	 *   <li>BeiDou B1I D2 = 1
+	 *   <li>BeiDou B2I D1 = 11
+	 *   <li>BeiDou B2I D2 = 11
+	 *   <li>QZSS L1C/A = 1
+	 *   <li>QZSS L1S = 4
+	 *   <li>QZSS L2 CM = 5
+	 *   <li>QZSS L2 CL = 6
+	 *   <li>GLONASS L1 OF = 1
+	 *   <li>GLONASS L2 OF = 3
+	 * </ul>
+	 *
+	 * @return signal ID
+	 */
+	int getSignalId();
+
 	/**
 	 * Get the index of this sentence in GSV sequence.
-	 * 
+	 *
 	 * @return Sentence index
 	 */
 	int getSentenceIndex();
 
 	/**
 	 * Tells if this is the first sentence in GSV sequence.
-	 * 
+	 *
 	 * @return true if first, otherwise false.
 	 * @see #getSentenceCount()
 	 * @see #getSentenceIndex()
@@ -82,22 +117,22 @@ public interface GSVSentence extends Sentence {
 	 * method for comparison of
 	 * {@code ({@link #getSentenceCount()} == {@link #getSentenceIndex()})}
 	 * .
-	 * 
+	 *
 	 * @return {@code true} if first, otherwise {@code false}.
 	 */
 	boolean isLast();
 
 	/**
 	 * Set the number of satellites in view.
-	 * 
+	 *
 	 * @param count Satellite count
 	 * @throws IllegalArgumentException If specified number is negative
 	 */
 	void setSatelliteCount(int count);
 
 	/**
 	 * Set the satellite information.
-	 * 
+	 *
 	 * @param info List of SatelliteInfo objects, size from 0 to 4.
 	 * @throws IllegalArgumentException If specified list size is greater that
 	 *             maximum allowed number of satellites per sentence (4).
@@ -106,15 +141,15 @@ public interface GSVSentence extends Sentence {
 
 	/**
 	 * Set the total number of sentences in GSV sequence.
-	 * 
+	 *
 	 * @param count Number of sentences
 	 * @throws IllegalArgumentException If specified count is negative
 	 */
 	void setSentenceCount(int count);
 
 	/**
 	 * Set the index of this sentence in GSV sequence.
-	 * 
+	 *
 	 * @param index Sentence index to set
 	 * @throws IllegalArgumentException If specified index is negative
 	 */

src/test/java/net/sf/marineapi/nmea/parser/GSVTest.java

@@ -17,7 +17,7 @@
 
 /**
  * Test the GSV sentence parser.
- * 
+ *
  * @author Kimmo Tuukkanen
  */
 public class GSVTest {
@@ -65,17 +65,17 @@ public void testGetSatelliteInfo() {
 		testSatelliteInfo(sat.get(2), "18", 63, 58, 50);
 		testSatelliteInfo(sat.get(3), "21", 53, 329, 47);
 	}
-	
+
 	/**
 	 * Test method for
 	 * {@link net.sf.marineapi.nmea.parser.GSVParser#getSatelliteInfo()}.
 	 */
 	@Test
 	public void testGetSatelliteInfoWithEmptyFields() {
-		
+
 		GSVSentence g = new GSVParser("$GPGSV,3,2,12,15,56,182,51,17,38,163,47,18,,,,21,53,329,47");
 		List<SatelliteInfo> sat = g.getSatelliteInfo();
-		
+
 		assertEquals(3, sat.size());
 		testSatelliteInfo(sat.get(0), "15", 56, 182, 51);
 		testSatelliteInfo(sat.get(1), "17", 38, 163, 47);
@@ -88,15 +88,15 @@ public void testGetSatelliteInfoWithEmptyFields() {
 	 */
 	@Test
 	public void testGetSatelliteInfoWithShortSentence() {
-		
+
 		GSVSentence g = new GSVParser("$GPGSV,3,2,12,15,56,182,51,17,38,163,47");
 		List<SatelliteInfo> sat = g.getSatelliteInfo();
-		
+
 		assertEquals(2, sat.size());
 		testSatelliteInfo(sat.get(0), "15", 56, 182, 51);
 		testSatelliteInfo(sat.get(1), "17", 38, 163, 47);
 	}
-	
+
 	/**
 	 * Test method for
 	 * {@link net.sf.marineapi.nmea.parser.GSVParser#getSentenceCount()}.
@@ -181,6 +181,40 @@ public void testParserGlonassGSV() {
 		assertEquals(TalkerId.GL, gl.getTalkerId());
 	}
 
+	@Test
+	public void testGetSignalIdWith1Satellite() {
+		final String EXAMPLE_WITH_SIGNALID = "$GAGSV,2,2,06,27,25,133,29,33,33,238,,2*71";
+		final GSVParser gsv = new GSVParser(EXAMPLE_WITH_SIGNALID);
+		assertEquals(2, gsv.getSignalId());
+	}
+
+	@Test
+	public void testGetSignalIdWith2SatellitesMsgNum1() {
+		final String EXAMPLE_WITH_SIGNALID = "$GAGSV,2,1,06,01,44,330,,13,33,031,19,21,75,093,38,26,73,310,,2*78";
+		GSVParser gsv = new GSVParser(EXAMPLE_WITH_SIGNALID);
+		assertEquals(2, gsv.getSignalId());
+	}
+
+	@Test
+	public void testGetSignalIdWith2SatellitesMsgNum2() {
+		final String EXAMPLE_WITH_SIGNALID = "$GPGSV,4,2,13,10,12,045,,11,47,333,42,14,,,40,16,15,193,33,1*5C";
+		final GSVParser gsv = new GSVParser(EXAMPLE_WITH_SIGNALID);
+		assertEquals(1, gsv.getSignalId());
+	}
+
+
+	@Test
+	public void testGetEmptySignalId() {
+		final String EXAMPLE_WITH_SIGNALID = "$GAGSV,2,2,06,27,25,133,29,33,33,238,,*43";
+		final GSVParser gsv = new GSVParser(EXAMPLE_WITH_SIGNALID); //12
+		try {
+			gsv.getSignalId();
+		} catch (DataNotAvailableException e) {
+			return;
+		}
+		fail("Expected a DataNotAvailableException to be thrown.");
+	}
+
 	/**
 	 * Tests the given SatelliteInfo against specified values.
 	 */