Introduction

The following describe a set of sensor data that AWOS (Automated Weather Observing System) Sensors can produce, and reference data associated with AWOS sensors. 

The "Core concepts" below describes the relationship between the sensors, the airport/runways and measurements produced.

Table of content

Core concepts

ConceptDescription
AirportEverything is related to an airport, identified by name (AirportName) , ICAO code (AirportICAO) and position. All sensors are associated with one airport given by the AirportICAO code.
Runway(s)

An airport has one or more runways. The runways are (of course) static, but the logical (compass oriented) name can change.

RunwaySectionEach runway has 3 RunwaySections (A, B, C) that are static. A runway section is exactly one third of the runway length. The runway sections are named A, B and C. Section naming starts at the lowest runway name (number). 
Sensors

Sensors take measurements of different things, from wind to cloud cover. Each measurement consists of one value of a defined type. If one physical sensor takes measurements of different types it will be considered as if separate sensors were used. Each sensor has a separate (logical) name and can only measure one type of measurements.

Sensors have a placement related to the airport. All sensors have a physical location given by coordinates. Sensors might also have a location associated with for instance a runway section.

Sensor position

Sensors have a static placement, but some can measure things that are non-local (cloud cover).
Sensors can have the following placements:

  • "Close" to the airport
  • Airport
  • Runway section
    • A
    • B
    • C
  • All sensors have a location given by coordinates.
Sensor types

Sensor (measurement) types. A sensor (or a group of sensors at the same location) can take different types measurements, as listed below. 

  • Wind
  • RunwayVisualRange
  • Visibility
  • PresentWeather
  • Temperature
  • Dewpoint
  • Humidity
  • Pressure
  • CloudCover
Sensor valuesThe sensor, or related software, can measure or calculate a set of values for the different measurement types. A temperature sensor can directly measure the temperature, and can calculate mean temperatures for different periods. Sensor values are of a defined type as given by the element description in the Airport Data Dictionary.
Sensor nameAll sensors have a name that is unique to the airport the sensor is associated with. The names is used to identify the sensor and relevant reference data.


Sensor Reference Data

TermDescription
SensorReferenceDataReference data for one sensor
The ICAO code for the airport this sensor is located at or close to.
Short name for the sensor. Unique for this airport.

The type of measurements this sensor can provide.

Short description of the sensor. 
Short text describing the placement of the sensor. For instance: "200 meters before runway 1".
Of the sensor.
Of the sensor.
The physical runway, if any, this sensor is associated with. 
The runway section, if any, this sensor is associated with.
When the reference data was last updated.
Time the reference data is valid from.
Time the reference data is valid to.


Sensor Measurement

TermDescription
SensorMeasurementOne measurement, or set of related measurements and calculations from one or more sensors at one airport at one point in time.
AirportICAOThe airport the sensor is related to.
MeasurementTime

Approximate time for the measurements. MeasurementTime is of type TimestampUTC, which means that it can be very precise. For AWOS measurements it is sufficient with seconds. 

RunwayInUse 0..*The runway(s) in use when the measurements were taken. Convenience since the AWOS system should know this.


  • Wind 0..*
Wind measurements from one or more sensors. 
Name of a wind sensor as given in SensorReferenceData. 
The current status of the sensor. 
The wind speed and direction at the MeasurementTime.

    • WindMean2
Values for the last two minutes.






    • WindMean10
Values for the last 10 minutes









  • Runway Visual Range 0..*
Runway visual range (RVR) measurements from one or more sensors. 
Name of the sensor as given in SensorReferenceData. 
The current status of the sensor. 
    • VisualRangeCurrent
Meter Maksverdi 2001, som betyr over 2.000 meter
    • RVRMean10

      • VisualRangeMin

      • VisualRangeMean

      • VisualRangeMax



  • Visibility 0..*

Visibility measurements from one or more sensors. 

What is the difference between RVR and visibility?  Robert sjekker ut.

Visibility er avstand man ser et lys på i dagslys.

[13:31] Robert Gustafsson

https://skybrary.aero/articles/runway-visual-range-rvr

Runway Visual Range (RVR) | SKYbrary Aviation Safety

Description Runway Visual Range (RVR) is the range over which the pilot of an aircraft on the centre line of a runway can see the runway surface markings or the lights delineating the runway or ide...


[13:31] Robert Gustafsson

https://skybrary.aero/articles/visibility

Visibility | SKYbrary Aviation Safety

Description Visibility is a measure of the distance at which an object or light can be clearly discerned. Visibility may vary according to the direction and angle of view, and the height of the obs...

    • SensorName
Name of the as given in SensorReferenceData. 
    • SensorStatus
The current status of the sensor. 
    • VisibilityCurrent
Alltid METER!  Ingen praktisk grense. 
    • VisibilityMean10

      • VisibilityMin

      • VisibilityMean

      • VisibilityMax



  • PresentWeather 0..*
Present weather measurements from one or more sensors. See also Wikipedia - Present weather sensor
    • SensorName
Name of the sensor as given in SensorReferenceData. 
    • SensorStatus
The current status of the sensor. 
    • PresentWeatherCurrentType
(fog, freezing fog, dust, etc) Numeriske koder 0-99, alternativt PL, PLSN, etc. Robert sender oversikt over hvilke dette kan være. Vi må sjekke med Arne om han ønsker tallverdien eller firebokstavsforkortelsen.
    • PresentWeather15Type

Samme som ovenfor, men det det har vært mest av de siste 15 min

More information about PRW data needed. Algorithm to derive percipitation is also needed.

    • PresentWeather60Type
Samme som ovenfor, men det det har vært mest av de siste 60 min
    • PrecipitationType
Se WMO4678 og 4680.
    • PrecipitationIntensity
(for hvilken periode?) Robert sjekker og sender over
    • AccumulatedWater
(for hvilken periode?) Robert sjekker og sender over
    • AccumulatedSnow
(for hvilken periode?) Robert sjekker og sender over


  • Temperature 0..*
Temperature measurements from one or more sensors. 
    • SensorName
Name of the sensor as given in SensorReferenceData. 
    • SensorStatus
The current status of the sensor. 
    • TemperatureCurrent
Temperature degrees Celsius?
    • TemperatureMean12Day
What is this?
      • TemperatureMin

      • TemperatureMean

      • TemperatureMax

    • TemperatureMean12Night
What is this?
      • TemperatureMin

      • TemperatureMean

      • TemperatureMax

    • TemperatureMean24
Is this the last 24 hours, or ..?
      • TemperatureMin

      • TemperatureMean

      • TemperatureMax



  • Dewpoint 0..*
Dewpoint measurements from one or more sensors. 
    • SensorName
Name of the sensor as given in SensorReferenceData. 
    • SensorStatus
The current status of the sensor. 
    • DewpointCurrent
Temperature in degrees Celsius?


  • Humidity 0..*
Humidity measurements from one or more sensors. 
    • SensorName
Name of the sensor as given in SensorReferenceData. 
    • SensorStatus
The current status of the sensor. 
    • HumidityCurrent
Måleenhet %
    • MeanMultiplied
What is this?


  • Pressure 0..*
Pressure measurements from one or more sensors. 
    • SensorName
Name of the sensor as given in SensorReferenceData. 
    • SensorStatus
The current status of the sensor. 
    • QFE
  • QFE. The atmospheric pressure at aerodrome elevation (or at runway threshold).

Unit: Hektopascal/mBar
1020.0 / 1020.05571914389


(ICAO, e.g. Doc 4444: PANS-ATM and Doc 8168: PANS-OPS)

https://skybrary.aero/articles/altimeter-pressure-settings

    • QNH
  • QNH. The altimeter sub-scale setting to obtain elevation when on the ground.

1021.7 / 1021.7962291178

    • QFF

Actual pressure at sea level. 

NB!! Hvor kommer dette fra. Sensoren står jo på lufthavnen.

1021.8 / 1021.83702659185

    • P0

Pressure at the sensor position at the airport.


Po=atmospheric pressure. If the pressure of a system is below atmospheric, it is called vacuum pressure. The SI unit of pressure is pascal (Pa): 1 Pa=1 N/m.

NB! Verify

1019.7 / 1019.77

    • Trl

NaN

Transition level??  Ikke sensorinformasjon.

    • Diff

0.3 / 0.323056791863564

Mellom hva? Og hvorfor?

    • Tend
8 / 8
Hva????


  • Cloud 0..*
Cloud measurements from one or more sensors. 
    • SensorName
Name of the sensor as given in SensorReferenceData. 
    • SensorStatus
The current status of the sensor. 
    • Layer1

      • Cover
0     Measurement unit?
      • LayerHeight
Measured in Feet
    • Layer2

      • Cover

      • LayerHeight

    • Layer3

      • Cover

      • LayerHeight

    • Base1
Matchende til layer?
      • BaseHeight
Feet
      • PenetrationDepth
Tykkelse på skylaget. Feet  Verifiser
    • Base2

      • BaseHeight

      • PenetrationDepth

    • Base3

      • BaseHeight

      • PenetrationDepth

    • VerticalVisibility

Istedenfor skylag/mengde. Brukes når det er for dårlig sikt til å se skyer (tåke, tett sne).

Feet