Water Level Message
U.S. Department of Transportation
John A. Volpe
Transportation Systems Center
55 Broadway
Cambridge, MA 02142
Details:
| Parameter | Number of bits | Description | |
| Designated Area Code |
10 | The Designated Area Code will be 366 for the United States or 316 for Canada depending on the location of transmitter. Refer to Section 1.1 for description |
|
| Function Identifier | 6 | FI=1 | |
| Reserved | 2 | ||
| Message ID | 6 | Message Identifier = 3 (00 0011 in binary) | |
| Binary Data | Max 864 | From 1 up to 4 wind information reports, each structured as defined in next table. | |
| Total Number of bits | Max 888 | = 24 + N*144 | |
| N Total Bits | (Slots Required) | ||
| 1 168 bits | (2 slots) | ||
| 2 312 bits | (2 slots) | ||
| 3 456 bits | (3 slots) | ||
| 4 600 bits | (4 slots) | ||
| 5 744 bits | (4 slots) | ||
| 6 888 bits | (5 slots) | ||
| Parameter | Number of bits | Description |
| Timetag | 20 | Month, Day and Time of measurement, See UTC Time |
| Station ID | 42 | Seven 6-bit ASCII character ID |
| Longitude | 25 | Longitude in 1/1000 minute (±180 degrees, East = positive, West = negative. 181 degrees = not available) |
| Latitude | 24 | Latitude in 1/1000 minute (±90 degrees, North = positive, South = negative. 91 degrees = not available) |
| Water Level Type | 1 | 0 or 1; 0 = Relative to reference datum , 1 = Water Depth , Note: Always 0 for Saint Lawrence Seaway |
| Water Level | 16 | Water level in centimeters -327.67 to +327.67 meters, -32767 = -327.67 m or less, +32767 = +327.67 m or greater -32768 = not available |
| Reference Datum | 2 | Defines datum used 0 = MLLW 1 = IGLD-85 2,3 = reserved for future use Note: Always 1 for Saint Lawrence Seaway |
| Reserved | 14 | Reserved for future use |
| Total Number of bits | 144 |
UTC Time
| Parameter | Number of bits | Description |
| Month | 4 | Month of year (01- 12 Month); 0 = not available; 13-15 not used |
| Day | 5 | Day of month (01 – 31 Days); 0 = not available |
| Hours | 5 | UTC Hours (0-23); 24 = not available; 25-31 not used |
| Minutes | 6 | UTC Minutes (0-59); 60 = not available; 61-63 not used |
| Total number of bits | 20 |
Water Level Report