afi met bulletins exchange (ambex) handbook - ICAO

AMBEX HANDBOOK 7th Ed. 11/58
3. DEFINITIONS AND SYMBOLS
3.1 Within the AMBEX Scheme, the following definitions and symbols are used:
i) AMBEX: AFI MET Bulletins Exchange (Scheme);
ii) AMBEX Bulletin: A collection of AMBEX messages originating from MET offices
within a collection area, always containing the same type of OPMET data and identified
by an appropriate identifier. Bulletins should not exceed 1800 characters in length;
iii) National OPMET center (NOC). Normally, a NOC is associated with the State’s
national AFTN centre/switch. The role of the NOC is to collect all OPMET messages
generated by the originating stations in the State and to send them to the responsible
AMBEX bulletin compiling center (AMBEX BCC). Some NOCs serve also as AMBEX
BCCs. National regulations should be developed to ensure that NOCs disseminate the
international OPMET data within their own State, as necessary.
iv AMBEX Bulletin Compiling Centre (BCC): AMBEX centres (former TCC, MCC or
ACC, etc..) are responsible for collection of OPMET messages from the originating
stations or NOCs in their area of responsibility and for compiling these messages into
AMBEX bulletins. FASID Tables MET 4A and MET 4B determine the areas of
responsibility (or, collection areas) of the AMBEX centres for METAR/SPECI, and TAF,
respectively.
v) OPMET Inter-regional Gateway (IROG) A designated centre charged with the
responsibility of exchanging OPMET data between stations within the AFI Region and in
adjacent regions, as prescribed in this Handbook. The plan of OPMET data exchange
between regions through an IROG is based on pre-determined distributions
responsibilities, and/or on a request/reply basis;
vi) YPYX: Fifth, sixth, seventh and eighth letter of an addressee indicator to be used:
a) with the normal four-letter location indicators, to designate BCCs
b) with indicators for pre-determined distribution within a BCC collection area.
vii) Regional OPMET Data Bank (RODB): A centre charged with task to collect OPMET
bulletins from AMBEX centres, handle all types of OPMET bulletins, provide facilities
for “request-reply” service to authorized users, maintain a catalogue of bulletins, quality
control the incoming bulletins and inform AMBEX centres on any deficiencies, monitor
the OPMET traffic and report to the ICAO Regional Office on the results
Note: The designated RODB and their responsibilities are described in Appendix E