Furuno SC-110 manual AP-5, GNS - GNNS fix data, HDM- Heading - magnetic, HDT - Heading - true

APPENDIX

GNS - GNNS fix data

$--GNS,hhmmss.ss,llll.lll,a,yyyyy.yyy,a,c					--	c,xx,x.x,x.x,x.x,x.x,x.x*hh<CR><LF>
												+--- 11
											+------	10
										+	----------	9
									+	--------------		8
								+	------------------			7
							+	----------------------				6
						+	-------------------------					5
					+------------------------------							4
			+-------	+---------------------------------								3
	+---	+	---------------------------------------------								2
+	-------------------------------------------------------------										1

1.UTC of position

2.Latitude, N/S

3.Longitude, E/W

4.Mode indicator

5.Total number of satllite in use,00-99

6.HDOP

7.Antenna altitude, metres, re:mean-sea-level(geoid)

8.Geoidal separation

9.Age of differential data

10.Differential reference station ID

11.Checksum

HDM- Heading – magnetic

This sentence is not used in the current version of NMEA and IEC 61162. Some boaters may want the GPS compass to indicate the magnetic heading when the boat is only fitted with a magnetic compass. HDG is calculated by adding a geomagnetic variation to HDT.

$--HDM, x.x, M *hh<CR><LF>

Heading, degrees true

HDT - Heading - true

True heading in degrees obtained by processing RF cycle in the GPS carrier frequency.

$--HDT, x.x, T*hh<CR><LF>

Heading, degrees true

ROT – Rate of turn

ROT derived from a changing rate of GPS compass heading.

$--ROT, x.x, A*hh<CR><LF>

Status: A = data valid

Rate of turn, degrees/min, “-” = bow turns to port

AP-5