wind direction clarification
Hallo guys...!!!
as new-by on this site I can not do everything better that brig to you a problem to solve.
I'm not a pilot but I'm responsible for an ATIS system that my company provides to some different airports all over the world.
In last days I went to one caribbean country to install and test a new ATIS system that, as required, does not receive data from AFTN line (and so by METAR), but directly from some metereological sensors installed directly on the field. This feature allows the system to continously update metereological data at each ATIS VHF trasmission.
The problem I had was that they required us to change the wind direction from the magnetic value incoming from the anemometer to a true value as reported in METAR.
Before to make any modification I would like to check what ICAO say according tha wind direction on ATIS.
In the ICAO Annex 10 nothing is specified according to the correct value to be used. However, ATIS system commonly take wind data from METAR or from METREPORT and, on those messages, according to ICAO Annex 3 wind as to be reported as true value....
As you have well understood I don't know how to retrieve information on that issue.
Does anyone know wich is the correct value to be reported into the ATIS message ???
Can anyone indicate any specification or document can I use?
Thank you...