12.1 This message provides environmental information from 1 to 8 sensor reports (e.g., 1 sensor report uses 2 slots while a message with 8 sensor reports can use up to 5 slots). Each sensor report carries the dynamic or static information relating to a specific sensor.
12.2 Each Environmental Message has 56 bits of standard header, with 12 bits available for payload. Each sensor report has 27 bits of common data leaving 85 bits for sensor data. Table 12.3 provides the framework for the sensor report.
12.2.1 Table 12.4 outlines a variety of sensor types that can be transmitted using this message.
12.2.2 The sensor data is defined in accordance to the sensor type. Tables 12.5 to 12.15 provide details for the 85 bits of information for each sensor report type. In each case "Sensor not available" means that the specific reading is not ever possible from that sensor location and "Data not available" means that the reading is possible but is not available for the current report (i.e. the sensor could be malfunctioning).
Table 12.1
Environmental
|
Parameter |
No of bits |
Description |
|
|
Standard Message Header |
Message ID |
6 |
Identifier for Message 8; Set to 8 (broadcast, no acknowledgement). |
|
Repeat Indicator |
2 |
Used by the repeater to indicate how many times a message has been repeated (see ITU-R M.1317, Annex 2, § 4.6.1). 0 - 3 0 = default 3 = do not repeat any more Set to 0 (default). |
|
|
Source MMSI |
30 |
MMSI number of source station. Varies according to the transmitter ID. |
|
|
Spare |
2 |
Not used. Set to zero. |
|
|
Binary Data |
Designated Area Code |
10 |
DAC = 001 |
|
Function Identifier |
6 |
FI = 26 |
|
|
Application Data |
Max 952 |
From 1 to 8 sensor reports, each structured as in Table 12.3. The total number of reports is determined by the receiver based on the length of the data. |
|
|
Total |
Max 1,008 |
Occupies 2-5 slots. (See Table 12.2) |
|
Table 12.2
Number of slots
|
Number of bits used |
168 |
280 |
392 |
504 |
616 |
728 |
840 |
952 |
|
Number of slots required (168 bits in first 210 in 2-5) |
1 |
2 (max 378) |
3 (max 588) |
3 |
4 (max 798) |
4 |
5 (max 1,008) |
5 |
Table 12.3
Environmental message - Sensor report framework
|
Parameter |
No of bits |
Description |
|
Report Type |
4 |
Environmental Report Type as defined in Table 12.4 |
|
Time Stamp |
|
UTC date and time. |
|
UTC Day |
5 |
1 - 31 0 = not available = default |
|
UTC Hour |
5 |
0 - 23 24 = not available = default |
|
UTC Minute |
6 |
0 - 59 60 = not available = default |
|
Site ID |
7 |
Binary identifier of sensor site, combined with transmitter MMSI to fully identify sensor site (i.e., there can be more than one physical sensors, each one reporting different data types at a sensor site) |
|
Sensor Data |
85 |
Sensor data according to the sensor type (see Tables 12.5 - 12.15) |
|
Total |
112 |
|
Table 12.4
Environmental Message Sensor Report Types
|
Value |
Description |
|
0 |
Site Location |
|
1 |
Station ID |
|
2 |
Wind |
|
3 |
Water level |
|
4 |
Current Flow (2D) |
|
5 |
Current Flow (3D) |
|
6 |
Horizontal Current Flow |
|
7 |
Sea State |
|
8 |
Salinity |
|
9 |
Weather |
|
10 |
Air gap / Air draft |
|
11-15 |
(reserved for future use) |
Table 12.5
Site location report
|
Parameter |
No of bits |
Description |
|
28 |
Longitude in 1/10,000 min, ±180 degrees as per 2's complement (East = positive, West = negative). 181 = not available = default |
|
|
Latitude |
27 |
Latitude in 1/10,000 min, ±90 degrees as per 2's complement (North = positive, South = negative). 91 degrees = not available = default |
|
Altitude |
11 |
Altitude of the sensor relative to MSL, in 0.1 metre steps. 0.0 - 200 metres 2,001 = altitude 201 metres or greater 2,002 = not available = default 2,003 - 2,046 (reserved for future use) |
|
Sensor Owner |
4 |
Owner of the sensor/responsible for the sensor data. 0 = unknown = default 1 = hydrographic office 2 = inland waterway authority 3 = coastal directorate 4 = meteorological service 5 = port authority 6 = coast guard 7 - 13 (reserved for future use[GWJ1] ) 14 (reserved for regional use) |
|
Data Timeout |
3 |
Length of time that data is valid (i.e., should not be used after timeout period). 0 = no timeout period = default 1 = 10 min 2 = 1 hr 3 = 6 hrs 4 = 12 hrs 5 = 24 hrs 6 - 7 (reserved for future use) |
|
Spare |
12 |
Not used. Set to zero |
|
Total |
85 |
|
|
Parameter |
No of bits |
Description |
|
Name |
84 |
Agency reference number. Fourteen characters 6-bits ASCII as defined in ITU-R M.1371-3, Table 44. |
|
Spare |
1 |
Not used. Set to zero. |
|
Total |
85 |
|
|
Parameter |
No of bits |
Description |
|
Average Wind Speed |
7 |
Average of wind speed values over the last 10 minutes, in 1 knot steps. 0 - 120 knots 121 = wind 121 knots greater 122 = not available = default 123 - 126 (reserved for future use) |
|
Wind Gust |
7 |
Max wind speed reading during the last 10 minutes, in 1 knot steps. 0 - 120 knots 121 = wind 121 knots or greater 122 = not available = default 123 - 126 (reserved for future use) |
|
Wind Direction |
9 |
Direction of the average wind over the last 10 minutes, in 1 degree steps. 0 - 359 degrees 360 = not available = default 361 - 511 (not for use) |
|
Wind Gust Direction |
9 |
Direction of the maximum wind over the last 10 minutes, in 1 degree steps. 0 - 359 degrees 360 = not available = default 361-511 (not for use) |
|
Sensor Data Description |
3 |
Type of data from Wind sensor, as defined in Table 12.16. |
|
Forecast Wind Speed |
7 |
Predicted average wind speed, in 1 knot steps. 0 - 120 knots 121 = wind 121 knots or greater 122 = not available = default 123 - 126 (reserved for future use) |
|
Forecast Wind Gust |
7 |
Predicted maximum wind speed, in 1 knot steps. 0 - 120 knots 121 = wind 121 knots or greater 122 = not available = default 123 - 126 (reserved for future use) |
|
Forecast Wind Direction |
9 |
Predicted direction of the average wind, in 1 degree steps. 0 - 359 degrees 360 = not available = default 361-511 (not for use) |
|
Valid Time of Forecast |
|
Valid UTC date and time of forecast. |
|
UTC Day |
5 |
1 - 31 0 = not available = default |
|
UTC Hour |
5 |
0 - 23 24 = not available = default |
|
UTC Minute |
6 |
0 - 59 60 = not available = default |
|
Duration |
8 |
Duration of the validity of the forecast from the time of the forecast, in 1 minute steps. 1 - 255 minutes 0 = cancel forecast = default |
|
Spare |
3 |
Not used. Set to zero. |
|
Total |
85 |
|
|
Parameter |
No of bits |
Description |
|
Water Level Type |
1 |
Type of water level. 0 = relative to reference datum 1 = water depth |
|
Water Level |
16 |
Water level, in 0.1 metre steps (as per 2's complement). -327.67 to +327.67 metres -32767 = -327.67 metres or less +32767 = +327.67 metres or greater -32768 = not available = default |
|
Water Level Trend |
2 |
0 = increasing 1 = decreasing 2 = steady 3 = not available = default |
|
Vertical Reference Datum |
5 |
Type of datum used. 0 = Mean Lower Low Water (MLLW) 1 = International Great Lakes Datum (IGLD-85) 2 = Local river datum 3 = Station Datum (STND) 4 = Mean Higher High Water (MHHW) 5 = Mean High Water (MHW) 6 = Mean Sea Level (MSL) 7 = Mean Low Water (MLW) 8 = National Geodetic Vertical Datum (NGVD-29) 9 = North American Vertical Datum (NAVD-88) 10 = World Geodetic System (WGS-84) 11 = Lowest Astronomical Tide (LAT) 12 = pool 13 = gauge 14 = unknown/not available = default 15 - 30 (reserved for future use) |
|
Sensor Data Description |
3 |
Type of data from Water Level sensor, as defined in Table 12.16. |
|
Forecast Water Level Type |
1 |
Type of water level for forecast 0 = relative to reference datum 1 = water depth |
|
Forecast Water Level |
16 |
Forecast water level, in 0.1 metre steps (as per 2's complement). -327.67 to +327.67 metres -32767 = -327.67 metres or less +32767 = +327.67 metres or greater -32768 = not available = default |
|
Valid Time of Forecast |
|
Valid UTC date and time of Forecast. |
|
UTC Day |
5 |
1 - 31 0 = not available = default |
|
UTC Hour |
5 |
0 - 23 24 = not available = default |
|
UTC Minute |
6 |
0 - 59 60 = not available = default |
|
Duration |
8 |
Duration of the validity of the forecast from the time of the forecast, in 1 minute steps. 1 - 255 minutes 0 = cancel forecast = default |
|
Spare |
17 |
Not used. Set to zero. |
|
Total No. bits |
85 |
|
|
Parameter |
No of bits |
Description |
|
Current Speed 1 |
8 |
Speed of Current 1 measured at a chosen level below the sea surface, in 0.1 knot steps. 0.0 - 24.5 knots 246 = speed 24.6 knots or greater 247 = data not available = default 248 - 255 (reserved for future use) |
|
Current Direction 1 |
9 |
Direction of Current 1, in 1 degree steps. 0 - 359 degrees 360 = not available = default 361-511 (reserved for future use) |
|
Current Measuring level 1 |
9 |
Measurement level of Current 1 below sea surface, in 1 metre steps. 0 - 360 metres 361 = 361 m or greater 362 = not available = default 363 - 511 (reserved for future use) |
|
Current Speed 2 |
8 |
Speed of Current 2 measured at a chosen level below the sea surface, in 0.1 knot steps. (Same as Current Speed 1) |
|
Current Direction 2 |
9 |
Direction of Current 2, in 1 degree steps. (Same as Current Direction 1) |
|
Current Measuring level 2 |
9 |
Measurement level of Current 2 below sea surface, in 1 metre steps. (Same as Current Measuring level 1) |
|
Current Speed 3 |
8 |
Speed of Current 3 measured at a chosen level below the sea surface, in 0.1 knot steps. (Same as Current Speed 1) |
|
Current Direction 3 |
9 |
Direction of Current 3, in 1 degree steps. (Same as Current Direction 1) |
|
Current Measuring level 3 |
9 |
Measurement level of Current 3 below sea surface, in 1 metre steps. (Same as Current Measuring level 1) |
|
Sensor Data Description |
3 |
Type of data from current sensor, as defined in Table 12.16. |
|
Spare |
4 |
Not used. Set to zero. |
|
Total |
85 |
|
|
Parameter |
No of bits |
Description |
|
Current Vector Component North (u) 1 |
8 |
Speed of North component of Current 1 measured at a chosen level below the sea surface, in 0.1 knot steps. 0.0 - 24.5 knots 246 = speed 24.6 knots or greater 247 = not available = default 248 - 254 (reserved for future use) |
|
Current Vector Component East (v) 1 |
8 |
Speed of East component of Current 1 measured at a chosen level below the sea surface, in 0.1 knot steps. 0.0 - 24.5 knots 246 = speed 24.6 knots or greater 247 = not available = default 248 - 254 (reserved for future use) |
|
Current Vector Component Up (z) 1 |
8 |
Speed of Up component of Current 1 measured at a chosen level below the sea surface, in 0.1 knot steps. 0.0 - 24.5 knots 246 = speed 24.6 knots or greater 247 = not available = default 248 - 254 (reserved for future use) |
|
Current Measuring level 1 |
9 |
Measurement level of Current 1 below sea surface, in 1 metre steps. 0 - 360 metres 361 = not available = default 362 - 511 (reserved for future use)[GWJ2] |
|
Current Vector Component North (u) 2 |
8 |
Speed of North component of Current 2 measured at a chosen level below the sea surface, in 0.1 knot steps. (Same as for Current 1) |
|
Current Vector Component East (v) 2 |
8 |
Speed of East component of Current 2 measured at a chosen level below the sea surface, in 0.1 knot steps. (Same as for Current 1) |
|
Current Vector Component Up (z) 2 |
8 |
Speed of Up component of Current 2 measured at a chosen level below the sea surface, in 0.1 knot steps. (Same as for Current 1) |
|
Current Measuring level 2 |
9 |
Measurement level of Current 2 below sea surface, in 1 metre steps. (Same as for Current 1) |
|
Sensor Data Description |
3 |
Type of data from Current sensor, as defined in Table 12.16. |
|
Spare |
16 |
Not used. Set to zero. |
|
Total |
85 |
|
|
Parameter |
No of bits |
Description |
|
Current Reading 1 Bearing |
9 |
Bearing of Current 1 reading from sensor position, in 1 degree steps. 0 - 359 degrees 360 = data not available = default 361 = sensor not available 362 - 511 (reserved for future use) |
|
Current Reading 1 Distance |
7 |
Distance of Current 1 reading from sensor position, in 1 metre steps[GWJ3] . 0 - 120 metres 121 = 121 m or greater 122 = not available = default 123 - 127 (reserved for future use) |
|
Current 1 Speed |
8 |
Speed of Current 1 measured at a chosen level below the sea surface, in 0.1 knot steps. 0.0 - 24.5 knots 246 = speed 24.6 knots or greater 247 = not available = default 248 - 255 (reserved for future use) |
|
Current 1 Direction |
9 |
Direction of Current 1, in 1 degree steps. 0 - 359 degrees 360 = data not available = default 361-511 (not for use) |
|
Current 1 Measuring level |
9 |
Measurement level of Current 1 below sea surface, in 1 metre steps. 0 - 360 metres 361 = level 361 metres or greater 362 = data not available = default 363 - 511 (reserved for future use) |
|
Current Reading 2 Bearing |
9 |
Bearing of Current 2 reading from sensor position, 1 degree steps. (Same as for Current 1 bearing) |
|
Current Reading 2 Distance |
7 |
Distance of Current 2 reading from sensor position, 1metre steps[GWJ4] . (Same as for Current 1 Distance) |
|
Current 2 Speed |
8 |
Speed of Current 2 measured at a chosen level below the sea surface, in 0.1 knot steps. (Same as for Current 1 Speed) |
|
Current 2 Direction |
9 |
Direction of Current 2, in 1 degree steps. (Same as for Current 1 Direction) |
|
Current 2 Measuring level |
9 |
Measurement level of Current 1 below sea surface, in 1 metre steps. (Same as for Current 1 level) |
|
Spare |
1 |
Not used. Set to zero. |
|
Total |
85 |
|
|
No of bits |
Description |
|
|
8 |
Height of the swell, in 0.1 metre steps. 0.0 - 24.5 metres 246 = height 24.6 metres or greater 247 = not available = default 248 - 255 (reserved for future use) |
|
|
Swell Period |
6 |
Swell period in seconds, in 1seccond steps. 0 - 60 seconds 61 = not available = default 62 - 63 (reserved for future use) |
|
Swell Direction |
9 |
Direction of swells, in 1 degree steps. 0 - 359 degrees 360 = not available = default 361-511 (reserved for future use) |
|
Sea State |
4 |
Beaufort Scale, as defined in Table 1.2 |
|
Sensor Data Description |
3 |
Type of data from Swell sensor, as defined in Table 12.16 |
|
Water Temperature |
10 |
Temperature of the water in degrees Celsius (as per 2's complement), in 0.1 degree steps. -10.0 to + 50.0 degrees Celsius temp = decimal value /10 - 10 for decimal = 0 - 600 601 = not available = default 602 - 1,023 (reserved for future use) |
|
Water Temperature Depth |
7 |
Depth of water temperature sensor, in 0.1 metre steps. 0 - 12.0 metres 121 = depth 12.1 metres or greater 122 = not available = default 123 - 126 (reserved for future use) |
|
Sensor Data Description |
3 |
Type of data from Water Temperature sensor, as defined in Table 12.16. |
|
Significant Wave Height |
8 |
Height of the waves, in 0.1 metre steps. 0.0 - 24.5 metres 246 = height 24.6 m or greater 247 = not available = default 248 - 255 (reserved for future use) |
|
Wave Period |
6 |
Wave period, in 1 second steps. 0 - 60 seconds 61 = not available = default 62- 63 (reserved for future use) |
|
Wave Direction |
9 |
Direction of waves, in 1 degree steps. 0 - 359 degrees 360 = not available = default 361 - 511 (reserved for future use) |
|
Sensor Data Description |
3 |
Type of data from Wave sensor, as defined in Table 12.16. |
|
Salinity |
9 |
Salinity in 0.1‰ (ppt) steps. 0.0 - 50.0‰ 501 = salinity 50.1‰ or greater 502 = data not available = default 503 = sensor not available 504 - 511 (reserved for future use) |
|
Total |
85 |
|
|
Parameter |
No of bits |
Description |
|
10 |
Temperature of water in degrees Celsius, in 0.1 degree steps. -10.0 to + 50.0 degrees temp = decimal value /10 - 10 for decimal = 0 - 600 601 = data not available 602 = sensor not available = default 603 - 1,023 (reserved for future use) |
|
|
Conductivity |
10 |
Water conductivity in Siemens/metre, in 0.01 S/m steps. 0.0 - 7.00 Siemens/metre 7.01 = conductivity 7.01 or greater 702 = data not available 703 = sensor not available = default, 704 - 1,023 (reserved for future use) |
|
Water Pressure |
16 |
Pressure of water in decibars, in 0.1 decibars steps. 0.0 to 6000.0 decibars 6000.1 = pressure 6000.1 or greater 60002 = data not available 60003 = sensor not available = default 60004 - 65535 (reserved for future use) |
|
Salinity |
9 |
Salinity in 0.1‰ (ppt) steps. 0.0 - 50.0 ‰ 50.1 = salinity 50.1 or greater 502 = data not available = default 503 = sensor not available 504 - 511 (reserved for future use) |
|
Salinity Type |
2 |
Type of salinity. 0 = measured 1 = calculated using PSS-78 2 = calculated using other method 3 (reserved for future use) |
|
Sensor Data Description |
3 |
Type of data from Salinity sensor, as defined in Table 12.16. |
|
Spare |
35 |
Not used. Set to zero. |
|
Total |
85 |
|
|
Parameter |
No of bits |
Description |
|
11 |
Dry bulb temperature in degrees Celsius (as per 2's complement), in 0.1 degree steps. -60.0 to +60.0 degrees Celsius -1,024 = data unavailable = default -1,023 to -601 (reserved for future use) 601 - 1,023 (reserved for future use) |
|
|
Sensor Data Description |
3 |
Type of data from Air Temperature sensor, as defined in Table 12.16. |
|
Precipitation (type) |
2 |
According to WMO 0 = rain 1 = snow 2 = rain and snow 3 = other |
|
Horizontal Visibility |
8 |
Visibility in Nautical Miles, in 0.1 NM steps. 0.0 - 24.0 NM 241 = visibility 24.1 NM or greater 242 = data not available 243 = sensor not available = default 244 - 255 (reserved for future use) |
|
Dew Point |
10 |
Dew point temperature in degrees Celsius (as per 2's complement), in 0.1 degree steps. -20.0 to +50.0 degrees Celsius
501 = not available = default 502-511 (reserved for future use) -511 to -201(reserved for future use) |
|
Sensor Data Description |
3 |
Type of data from Dew Point sensor, as defined in Table 12.16. |
|
Air Pressure |
9 |
Air pressure, defined as pressure reduced to sea level, in 1 hPa steps. 0 = pressure 800 hPa or less 1 - 401 = 800 - 1200 hPa 402 = pressure 1201 hPa or greater 403 = data not available = default 404 - 511 (reserved for future use) |
|
Air Pressure Trend |
2 |
Air pressure trend 0 = steady 1 = decreasing 2 = increasing 3 = undefined = default |
|
Sensor Data Description |
3 |
Type of data from air pressure sensor, as defined in Table 12.16. |
|
Salinity |
9 |
Salinity in 0.1‰ (ppt) steps. 0.0 - 50.0 ‰ 501 = salinity 50.1 or greater 511 = data not available = default 512 = sensor not available 503 - 511 (reserved for future use) |
|
Spare |
25 |
Not used. Set to zero. |
|
Total |
85 |
|
|
Parameter |
No of bits |
Description |
|
Air Draught
|
13 |
Vertical distance measured from the ship's waterline to the highest point on the ship, in 0.1 metre steps. 1 - 81.90 metres 8,191 = distance 81.91 metres or greater 0 = data not available = default |
|
Air Gap |
13 |
Vertical distance measured from the surface of the water to the sensor, in 0.1 metre steps. 1 - 81.9 metres 8,191 = distance 81.91 metres or greater 0 = data not available = default |
|
Air Gap Trend |
2 |
Trend of the air gap measurement. 0 = steady 1 = rising 2 = falling 3 = no data = default |
|
Forecast Air Gap |
13 |
The forecast vertical distance measured from the surface of the water to the sensor, in 0.01 metre steps. This is the measurement for the time of the forecast. 1 - 81.90 metres 8,191 = distance 81.91 metres or greater 0 = data not available = default |
|
Valid Time of the Forecast |
|
Valid UTC date and time of the forecast. |
|
UTC Day |
5 |
1 - 31 0 = not available = default |
|
UTC Hour |
5 |
0 - 23 24 = not available = default 25 - 31 (reserved for future use) |
|
UTC Minute |
6 |
0 - 59 60 = not available = default 61 - 63 (reserved for future use) |
|
Spare |
28 |
Not used. Set to zero. |
|
Total |
85 |
|
Type of data from sensor
|
Value |
Description |
|
0 |
no data = default |
|
1 |
raw real time |
|
2 |
real time with Quality Control |
|
3 |
predicted (based historical statistics) |
|
4 |
forecast (predicted, refined with real-time information) |
|
5 |
Nowcast (a continuous forecast) |
|
6 |
(reserved for future use) |
|
7 |
sensor not available |
[GWJ1] [1]This needs to be generalized to support International usage.
[GWJ2] [2]Maybe only keep the deep depth here not in version 1
[GWJ3] [3]Check with ACE if this is sufficient distance and resolution.
[GWJ4] [4]Check with ACE if this is sufficient distance and resolution.