How do you decode real-time data?

DECODING BUOY DATA

The following is an example of a NDBC buoy observation in FM-13 code.

42003 28121 99259 70859 46/// /2211 10285 20253 30113 40113
57012 91150 22200 00289 10603 20502 318// 41201 70013 333 91213
555 11107 22114 31127 42314 61149 223113 225107 219111
228116 227103 217100=

The decoding follows:

42003     STATION IDENTIFIER             First two numbers indicate WMO region.

28121     TIME AND WIND UNITS            28=Day, 12=hour(UTC), 1=measured speed in m/s.

99259     LATITUDE                       25.9 degrees (in this case N latitude)

70859     LONGITUDE & QUADRANT           7=quadrant of globe that buoy is located,
                                         where
                                            1= N latitude & E longitude
                                            3= S latitude & E longitude
                                            5= S latitude & W longitude
                                            7= N latitude & W longitude

                                         0859= 85.9 W longitude

/2211     WIND DIRECTION & SPEED         Wind blowing from 220 degrees at 11 m/s

10285     AIR TEMPERATURE                0285=+28.5ø C, 1285=-28.5ø C

20253     DEW POINT TEMPERATURE          0253=+25.3ø C, 1253=-25.3ø C

30113     STATION BARO. PRESSURE         30113=1011.3 hPa, 39995=999.5 hPa

40113     SEA LEVEL PRESSURE             40113=1011.3 hPa, 49995=999.5 hPa

57012     3 HR. PRESSURE TENDENCY        Pressure 1.2 hPa lower than three hours ago

91150     END OF ACQUISITION TIME        The end of data acquisition=1150 UTC

00289     SEA WATER TEMPERATURE          0289=+28.9 C, 1010=-1.0 C

10603     SEA STATE                      Dominant period=6 sec., Wave height=3 half meters

20502     WIND WAVE HEIGHT & PERIOD      The wind-wave height is one-meter (02 = 2 half-meters)
                                         and wind-wave period is 5 seconds.

318//     PRIMARY SWELL DIRECTION        The primary swell direction = 180 deg. (from the south); 
                                         only buoys reporting directional waves encode this group.

41201     SWELL HEIGHT & PERIOD          The swell height is a half-meter (01 = one half-meter)
                                         and the primary swell period is 12 seconds.

70013     WAVE HEIGHT                    Significant wave height= 1.3 meters
                                         (higher precision)

91213     PEAK WIND GUST                 5-sec. peak wind during 8-minute
                                         acquisition interval=13 m/s.

11107     WIND AT 10 METERS              Estimated wind at 10 meters elevation=10.7 m/s.

22114     WIND AT 20 METERS              Estimated wind at 20 meters elevation=11.4 m/s.

31127     TIME OF PEAK 5-SEC WIND        11=UTC hour, 27=minutes after the hour

42314     5-SEC PEAK WIND SPD/DIR        23=230 degrees, 14=14 meters/sec.

61149     TIME OF CONTINUOUS WIND        1149=end time in hours and minutes (UTC) of
                                         latest 10-minute continuous wind.

223113    LATEST 10-MIN CONT. WIND       223=223 degrees, 113=11.3 m/s

225107    NEXT OLDER 10-MIN CONT. WIND   225=225 degrees, 107= 10.7 m/s
                    "
                    "
                    "
217100    6th OLDEST 10-MIN CONT. WIND   217=217ø, 100=10.0 m/s

NOTE: Some groups may not be included in an individual message.

DECODING C-MAN DATA

The following is an example of an NDBC C-MAN observation in code.

CMAN 20124
DSLN7 46/// /0113 10110 20095 40292 52021 91200 222// 00204 10703
70016 333 91218 555 11012 22012 31135 402021 61159 005012 022011
008012 007012 011011 007012 TIDE1157=

The decoding follows:

CMAN      Heading indicating that the following stations are Coastal Marine Stations

20124     TIME AND WIND UNITS            20=day of month, 12=1200 UTC, 4=wind in knots

DSLN7     STATION IDENTIFIER             Diamond Shoals Light, NC

/0113     WIND DIR. & SPEED              Wind blowing from 010 at 13 knots

10110     AIR TEMPERATURE                0110=11.0C, 1110=-11.0C

20095     DEW POINT TEMP.                0095=9.5C, 1095=-9.5C

40292     SEA LEVEL PRESSURE             40292=1029.2 hPa, 49995=999.5 hPa

52021     3hr. PRESS. TENDENCY           Pressure 2.1 hPa higher than 3 hrs ago

91200     END OF ACQ. TIME               end of data acquisition=1200 UTC

00204     SEA WATER TEMP.                0204=20.4C, 1204=-20.4C

10703     SEA STATE                      dominant period=7 sec., wave hgt=3 half meters

70016     REFINED SEA STATE              hgt of highest 1/3 waves=1.6 meters

91218     PEAK WIND GUST                 highest peak wind gust=18 knots

11012     WIND SPD AT 10m                wind speed at 10m above site elev.=12 knots

22012     WIND SPD AT 20m                wind speed at 20m above site elev.=12 knots

31135     TIME OF MAX WIND SPEED         11=11 UTC, 35=35 min. after the hr.

402021    MAX WIND SPEED & DIR.          020=20 degrees, 21=21 knots

61159     TIME OF CONT. WIND             1159=end time in hours and minutes (UTC) of
                                         latest 10-minute continuous wind.

005012    LATEST 10-MIN CONT. WIND       005=5 degrees, 012= 12 knots

022011    NEXT OLDER 10-MIN CONT WIND    022=22 degrees, 011=11 knots

                    "
                    "
                    "
007012    6th OLDEST CONTINUOUS WIND     007=7 degrees, 012=12 knots

TIDE1157  TIDAL HEIGHT                   tidal height is 1.57 feet above
                                         Mean Lower Low Water (MLLW)

Note: Some groups may not be included in an individual message.