TRACKOB

Report of marine surface observation along a ship's track

Section 1

NNXX YY MM J

Section 2

GGgg/ Q_c L_aL_aL_aL_a L_oL_oL_oL_oL_o 4m_Tm_Sm_c i_c (6s_n T_wT_wT_w) (8S₀S₀S₀S₀) (9d₀d₀ c₀c₀)

Section 3

D.....D

---

YY

Day of the month (UTC), with 01 indicating the first day, 02 the second day,etc. on which the actual time of observation falls

MM

Month of the year (UTC), i.e. 01=January; 02=February, etc.

J

Units digit of the year (UTC), i.e. 1994 = 4

GGgg

Time of observation, in hours and minutes (UTC)

Q_c

Quadrant of the globe.

Code figure	Latitude	Longitude
1	North	East
3	South	East
5	South	West
7	North	West

Note: The choice is left to the observer in the following cases:

When the ship is on the Greenwich meridian or the 180th meridian (LoLoLoLo = 0000 or 1800 respectively):
Qc = 1 or 7 (northern hemisphere) or
Qc = 3 or 5 (southern hemisphere);
When the ship is on the Equator (LaLaLa = 000):
Qc = 1 or 3 (eastern longitude) or
Qc = 5 or 7 (western longitude).

L_aL_aL_aL_a

Latitude, in degrees and minutes

L_oL_oL_oL_oL_o

Longitude, in degrees and minutes

m_T
m_S
m_c

m_T Averaging period for sea temperature
m_S Averaging period for salinity
m_c Averaging period for surface current direction and speed Code figure 0 Spot values 1 Less than 15 minutes 2 From 15 to 45 minutes 3 More than 45 minutes 9 Data not available

i_c

Indicator for units of sea-surface current speed Code figure 0 Metres per second 1 Knots 9 No sea-current data available

s_n

Sign of the data

  code
  figure
  0 Positive or zero
  1 Negative

T_wT_wT_w

Sea-surface temperature, in tenths of a degree Celsius, its sign being given by s_n

S₀S₀S₀S₀

Salinity, in hundredths of a part per thousand (practical salinity), at the surface.

d₀d₀

True direction, in tens of degrees, towards which sea-surface current is moving

  Code
  figure
  00 Calm
  01 5-14
  02 15-24
  03 25-34
  
  etc. etc.

  36 355-4 
  99 Variable, or all directions or unknown or waves confused, direction
  indetermininate 

c₀c₀

Sea-surface current speed, in tenths of a meter per second or tenths of a knot, in units indicated by i_c
d₀d₀c₀c₀ is encoded 0000 if the current speed is less than 0.05 meter per second (0.1 knot)

D.....D

Ship's call sign consisting of three or more alphanumeric characters