: Public Class
Created: 02/05/2012 3:24:57 PM
Modified: 27/03/2013 3:16:43 PM
Project:
Advanced:
A specialized Record type containing meteorological conditions observed at an aerodrome.  <br /></p><p><br /></p><p>When no clouds of operational significance or no weather of operational significance is observed, the NothingOfOperationalSignificance nilReason should be used for the cloud or presentWeather association. When no clouds were detected by the automatic observing system, the NotDetectedByAutoSystem nilReason should be used for the cloud association.<br /></p>
Attribute
Public Measure
  airTemperature

Details:
quantity=http://codes.wmo.int/common/c-15/me/airTemperature
sequenceNumber=7
Notes: The observed air temperature.  This is the temperature indicated by a thermometer exposed to the air in a place sheltered from direct solar radiation.
Public Boolean
  cloudAndVisibilityOK

Details:
sequenceNumber=1
xsdAsAttribute=true
Notes: When true, indicates that the observed cloud ceiling, horizontal visibility, and weather conditions are of no operational significance.  See ICAO Annex 3 / WMO No. 49-2 Section 2.2. Also known as "CAVOK"<br /></p><p><br /></p><p>When CAVOK conditions are observed, no other information on visibility, runway visual range, present weather, cloud amount, or cloud type shall be reported<br /></p>
Public Measure
  dewpointTemperature

Details:
quantity=http://codes.wmo.int/common/c-15/me/dewPointTemperature
sequenceNumber=8
Notes: The observed dew point temperature.  This is the temperature to which a given air parcel must be cooled at constant pressure and constant water vapor content in order for saturation to occur.
Public Measure
  qnh

Details:
quantity=http://codes.wmo.int/common/c-15/me/altimeterSettingQnh
sequenceNumber=9
Notes: The observed QNH altimeter setting.<br /></p><p><br /></p><p>Altitude setting (also known as QNH) is defined as barometric pressure adjusted to sea level. It is a pressure setting used by pilots, air traffic control (ATC), and low frequency weather beacons to refer to the barometric setting which, when set on an aircraft's altimeter, will cause the altimeter to read altitude above mean sea level within a certain defined region.<br /></p>
Element Source Role Target Role
«DataType» AerodromeObservedClouds
Class   		Name:  
  		Name: cloud
 
Details:
When no clouds are detected by the automatic observing system, it should be indicated by a missing cloud group with a nil reason of notDetectedByAutoSystem ("NCD" from TAC).  <br /></p><p><br /></p><p>When there are no clouds of operational significance and no restriction on vertical visibility and “CAVOK” is not appropriate ("NSC") it should be indicated by a missing cloud group with a nil reason of nothingOfOperationalSignificance<br /></p><p><br /></p>
«DataType» AerodromeHorizontalVisibility
Class   		Name:  
  		Name: visibility
 
Details:
 
«CodeList» AerodromePresentWeather
Class   		Name:  
  		Name: presentWeather
 
Details:
When observed, between one and three present weather conditions<br /></p><p><br /></p><p>When present weather cannot be observed by the automatic observing system due to a temporary failure of the system/sensor ("//") the present weather shall be missing with a nil reason of notObservable.<br /></p>
«DataType» AerodromeSurfaceWind
Class   		Name:  
  		Name: surfaceWind
 
Details:
 
«DataType» AerodromeWindShear
Class   		Name:  
  		Name: windShear
 
Details:
 
«DataType» AerodromeSeaState
Class   		Name:  
  		Name: seaState
 
Details:
 
«CodeList» AerodromeRecentWeather
Class   		Name:  
  		Name: recentWeather
 
Details:
 
«DataType» AerodromeRunwayVisualRange
Class   		Name:  
  		Name: rvr
 
Details:
RVR conditions are required if horizontal visibility or RVR is less than 1500 meters, up to a maximum of four runways
«DataType» AerodromeRunwayState
Class   		Name:  
  		Name: runwayState
 
Details:
When runways are affected by snow, slush, or other contaminants, a runway state report for each runway in use is required.<br /></p><p><br /></p><p>There is no maximum number of runway states that can be reported.  This may be changed in a future amendment.<br /></p>
Element Source Role Target Role
«FeatureType» MeteorologicalAerodromeObservation
Class   		Name:  
  		Name: result
 
Details:
 
Constraint Type Status
if( cloudAndVisibilityOK ) visibility == NULL Invariant Approved
Details:
 
if( cloudAndVisibilityOK ) rvr == NULL Invariant Approved
Details:
 
if( cloudAndVisibilityOK ) presentWeather == NULL Invariant Approved
Details:
 
if( cloudAndVisibilityOK ) clouds == NULL Invariant Approved
Details:
 
if( visibility != NULL && visibility.prevailingVisibility < 1500 ) rvr.size() > 0 Invariant Approved
Details:
Table A3-2 Note 7 states: "To be included if visibility or RVR < 1500 m; for up to a maximum of four runways".  This is interpreted to mean that if the prevailing visibility is below 1500 meters, RVR should always be included