Add support for Cerulean Sonar ROV Locator

pynmea2/types/talker.py

@@ -1035,4 +1035,26 @@ class ALK(TalkerSentence,SeaTalk):
         ("Data Byte 7", "data_byte7"),
         ("Data Byte 8", "data_byte8"),
         ("Data Byte 9", "data_byte9")
+    )
+
+
+# RTH
+# Used by Cerulean Sonar ROV Locator
+class RTH(TalkerSentence):
+    """
+    RTH
+    """
+    fields = (
+        ("Apparent Bearing to Target in Degrees", "ab", float),
+        ("Apparent Bearing to Target in Compass Degrees", "ac", float),
+        ("Apparent Elevation to Target in Degrees", "ae", float),
+        ("Slant Range in Meters", "sr", float),
+        ("True Bearing to Target in Degrees", "tb", float),
+        ("True Bearing to Target in Compass Degrees", "cb", float),
+        ("True Elevation to Target in Degrees", "te", float),
+        ("Euler Roll", "er", float),
+        ("Euler Pitch", "ep", float),
+        ("Euler Yaw", "ey", float),
+        ("Compass Heading", "ch", float),
+        ("AGC Gain in db", "db", float)
     )

test/test_cerulean.py

@@ -0,0 +1,22 @@
+import pynmea2
+
+
+def test_cerulean():
+    data = '$USRTH,358.5,1.5,2.8,142.8,52.8,37.2,2.8,-0.6,1.9,178.1,271.9,16*49'
+    msg = pynmea2.parse(data)
+
+    assert type(msg) == pynmea2.types.talker.RTH
+    assert msg.sentence_type == 'RTH'
+    assert msg.talker == 'US'
+    assert msg.ab == 358.5
+    assert msg.ac == 1.5
+    assert msg.ae == 2.8
+    assert msg.sr == 142.8
+    assert msg.tb == 52.8
+    assert msg.cb == 37.2
+    assert msg.te == 2.8
+    assert msg.er == -0.6
+    assert msg.ep == 1.9
+    assert msg.ey == 178.1
+    assert msg.ch == 271.9
+    assert msg.db == 16.0