IALA

EMMA warning

Introduction/Additional information:

The EMMA warning shall be used to warn shippers using graphical symbols on the ECDIS screen of heavy weather conditions. The following message is capable of transmitting the EMMA data using the AIS channel. It will not replace the Notices to Skippers warnings.

This message should be sent by base stations only, to give weather warnings to all vessels in a certain area. The message should be sent with binary message 8 on demand.

Registrant:
EU
Message number:
8
DAC:
200
FI:
23
State:
in force
Number of slots (max):
2
Permitted as from:
10/10/2007
Details:

 

 Parameter  Bit  Description
 Message ID 6  Identifier for Message 8;  always 8
 Repeat Indicator 2  Used by the repeater to indicate how many times a message has been repeated. Default = 0;  3 = do not repeat any more
 Source ID 30  MMSI number
 Spare 2  Not used, should be set to zero. Reserved for future use.
 Application Identifier 16  As described in Table 2,6
 Start date 17  Start of validity period (YYYYMMDD),
Bits 18-10: year since 2000 1-255 0 = default)
Bits 9-6: month (1-12  0 = default)
Bits 5-1: day (1-31 0 = default)
 End date 17  End of validity period (YYYYMMDD),
Bits 18-10: year since 2000 1-255 0 = default)
Bits 9-6: month (1-12  0 = default)
Bits 5-1: day (1-31 0 = default)
 Start time 11  Start time of validity period (HHMM) UTC
Bits 11-7: hour (0-23 24 = default)
Bits 6-1: minute (0-59  60 = default)
 End time 11  End time of validity period (HHMM) UTC
Bits 11-7: hour (0-23 24 = default)
Bits 6-1: minute (0-59  60 = default)
 Start longitude 28  Begin of the fairway section
 Start latitude 27  Begin of the fairway section
 End longitude 28  End of the fairway section
 End latitude 27  End of the fairway section
 Type 4  type of weather warning: 0 = default/unknown, others see ANNEX B: EMMA CODES Table B.1
 Min value 9  Bit 0: 0 = positive, 1 = negative value = default Bits 1 – 8 = value (0 – 253 254 = 254 or greater, 255 = unknown = default)
 Max value 9  Bit 0: 0 = positive, 1 = negative value = default Bits 1 – 8 = value (0 – 253 254 = 254 or greater, 255 = unknown = default)
 Classification 2  classification of warning (0 = unknown/default, 1 = slight, 2 = medium, 3 = strong/heavy) according to ANNEX B: EMMA CODESTable B.2
 Wind direction 4  direction of wind: 0 = default/unknown, others see ANNEX B: EMMA CODESAnnex B Table B.3
 Spare 6  not used, should be set to zero. Reserved for future use.
256  occupies 2 slots

Table 2.12: Weather type code

 Code   Description (EN)  AIS
 WI   Wind 1
 RA  Rain 2
 SN  Snow and ice 3
 TH   Thunderstorm 4
 FO   Fog 5
 LT   Low temperature 6
 HT   High temperature 7
 FL   Flood 8
 FI  Fire in the forests 9

Table 2.13: Weather category type code

 Code   Description (EN)  AIS
1  Slight 1
2  Medium 2
3  strong, heavy 3

Table 2.14: Wind direction code

 Code   Description (EN)  AIS
 N  North 1
 NE  North east 2
 E  East 3
 SE  South east 4
 S  South 5
 SW   South west 6
 W  West 7
 NW  North west 8