What weather sensors are used at airports?
Airport weather systems combine wind, temperature, humidity, pressure, precipitation, visibility and runway information to support operational decisions. The sensor specification depends on what the measurement is used for, where it is installed and, for critical wind measurements, what formal acceptance the system requires.
An airport weather system is not simply a collection of weather instruments. Each measurement exists because somebody needs the information to make a decision.
Wind can affect runway selection and crosswind or tailwind assessment. Temperature and pressure contribute to aircraft performance and altimeter settings. Humidity and dew point help characterise conditions associated with fog and icing. Precipitation affects runway condition and operational planning. Visibility and cloud information can affect approach and low-visibility procedures.
That means the useful question is not what weather sensors an airport needs. It is what the airport needs to know, where it needs to know it, and what evidence that measurement has to meet.
Every parameter has a job
| Parameter | Why the airport needs it |
|---|---|
| Wind speed and direction | Runway selection, crosswind and tailwind assessment, gust reporting and operational wind information |
| Air temperature | Aircraft performance calculations and density-altitude considerations |
| Relative humidity and dew point | Assessment of fog, icing and atmospheric conditions |
| Barometric pressure | QNH and QFE, where applicable |
| Precipitation | Identification and monitoring of rain and other precipitation affecting operations |
| Runway surface condition | Surface sensors report temperature and surface state to support the runway assessment. The runway condition code itself is assigned by trained aerodrome personnel under the ICAO Global Reporting Format, not derived by a sensor. |
| Visibility and cloud information | Approach operations and low-visibility procedures |
No single sensor measures all seven. Airport meteorological systems combine several sensor types, and the measurements can be distributed across a network. The runway system may require one set of measurements. Aprons, de-icing areas, fuel facilities, construction areas and other airport locations may have different requirements.
Wind gets treated differently because the decision is immediate
Wind speed and direction can feed directly into operational decisions around aircraft movement. That changes the importance of the sensor’s behaviour, availability, installation and acceptance.
The key issue is not simply whether the sensor can measure wind accurately under laboratory conditions. It is whether the specified instrument is accepted for the operational system in which the measurement will be used. Airport wind measurement should therefore be specified against the complete system requirement.
The wind sensor is specified against the job, not just the accuracy number
For an AWOS surface-wind application, the relevant question is not how accurate the sensor is. It is whether this specific sensor is accepted for the intended application.
Within the Gill range, the WindObserver 70 is the model whose datasheet states FAA and CAA acceptance for AWOS surface wind reporting.
WindObserver 70
- 0 to 70 m/s measurement range
- Stainless steel 316 construction
- IP66 protection
- Heated
- FAA and CAA acceptance stated in the product datasheet for AWOS surface wind reporting
- Lloyd’s Register Type Approval
The Lloyd’s Register Type Approval is a separate form of approval from the FAA and CAA acceptance. One is not the basis for the other.
Other WindObserver models may offer different measurement ranges or application characteristics, but that does not transfer the FAA and CAA acceptance statement to those models. Acceptance is a property of the specified model and application.
The highest specification is not automatically the correct airport specification
A sensor can have an excellent accuracy figure and still be unsuitable for a particular airport system if it lacks the required acceptance, interface, environmental performance or installation compatibility. Equally, a sensor does not need every available feature if the application does not require it.
The specification should therefore begin with the application, the required acceptance, the measurement range, the environmental conditions, the installation, the output and the maintenance strategy. Accuracy then sits inside that frame rather than in front of it. Accuracy still matters. It is one requirement among several.
The sensor has to measure the runway wind, not the building wind
An airport wind sensor is installed to represent the wind relevant to aircraft operations. That makes siting critical. A technically excellent sensor can produce a poor operational measurement if the surrounding structures distort the airflow.
Exposure
The sensor needs representative exposure rather than simply maximum height.
Obstructions
Buildings, terminal structures, masts and other airport infrastructure can alter the local flow.
Multiple locations
Long runways or different runway thresholds may require multiple wind measurement locations so the system can represent conditions relevant to the runway in use.
Mounting
Where the installation falls within relevant protected or obstacle-limitation areas, the mounting structure may need to meet frangibility requirements.
Heating
Where freezing conditions can cause icing, the wind-sensor specification needs to address heating or another approved means of maintaining measurement availability. WindObserver 70 is a heated model.
A perfect sensor in the wrong place is still the wrong measurement
Sensor performance and measurement representativeness are different questions. The sensor can meet its laboratory specification while the installed measurement is affected by buildings, hangars, masts, vehicles, terrain, structures, local turbulence, installation height and mounting geometry. The siting design therefore belongs in the measurement specification, and it needs project-specific information about the airport rather than a general rule.
The airport has weather systems that are not part of the runway system
Airports contain many operational areas where local environmental information can be useful: apron areas, de-icing pads, fuel-handling areas, construction zones, temporary works, solar installations and the wider airport estate.
These applications may not require the same sensor or formal acceptance as a runway AWOS installation. This is where compact integrated weather stations can make sense. MaxiMet can provide multiple environmental parameters from a single compact unit, with the parameters depending on the model specified. The specification should follow the application.
When one instrument is enough, and when it is not
An integrated weather station is useful where multiple parameters need to be measured from one compact installation. The advantages can include one physical unit, simpler installation, fewer cables and a shared location. That shared location can also become a limitation if different parameters need different exposure or mounting heights.
A separable or modular system is useful where individual measurements need to be positioned according to their own siting requirements, or where third-party sensors need to be incorporated. MetConnect can support installations where separated sensor placement is required.
Airports are harsh in ways that are easy to overlook
An airport weather sensor may experience freezing conditions, precipitation, high winds, jet blast or disturbed airflow, vibration, dust, de-icing chemicals, salt at coastal airports, electromagnetic interference and continuous outdoor exposure. Not every airport experiences every condition, so the specification should be based on the actual site. IP66 addresses ingress protection under defined test conditions and stainless steel addresses aspects of corrosion. Neither answers the environmental question on its own.
Around fuel, the wind question becomes a certification question
Fuel-handling areas may introduce hazardous-area classification. Where the wind sensor itself must operate in a classified area, hazardous-area certification becomes part of the specification.
Gill’s WindObserver IS is the intrinsically safe anemometer in the range. It uses a certified interface located in the non-hazardous area. The supplied part numbers are WindObserver IS 1360-PK-052, the LVPCI low-voltage interface 1360-PK-055 and the mains interface 1360-PK-053. The certification covers the defined installation arrangement, so the sensor certification cannot be treated as independent of the interface and the installation.
Intrinsic safety does not make every other requirement disappear
WindObserver IS addresses hazardous-area requirements. It does not automatically solve icing, marine type approval, calibration or every environmental requirement. WindObserver IS is unheated. It does not carry the Lloyd’s Register Type Approval held by specified WindObserver marine models. And while its factory calibration is traceable to national standards, individual calibration certificates are not available as they are elsewhere in the range. These distinctions matter when the airport specification combines several requirements. The IS is not a lesser instrument. It is solving a different requirement.
How we approach airport weather measurement
Airport weather measurement does not stop at the runway. Gill’s weather portfolio includes dedicated ultrasonic wind sensors and integrated weather stations, allowing the instrument to be selected around the measurement rather than forcing every airport application into one configuration.
For formal AWOS surface-wind reporting, the WindObserver 70 is the Gill model whose datasheet states FAA and CAA acceptance. For other airport environments the requirement may be different. A MaxiMet weather station can be appropriate where a compact installation needs multiple environmental parameters rather than a dedicated runway-wind instrument. MetConnect can be considered where a more configurable or separated weather-sensing architecture is required. The airport application determines the instrument.
| Airport requirement | Gill approach |
|---|---|
| AWOS surface wind reporting | WindObserver 70, subject to the applicable system requirements |
| Dedicated airport wind measurement | Appropriate WindObserver variant according to range, environment and application |
| Compact weather monitoring away from the runway | MaxiMet, model selected by required parameters |
| Configurable or modular weather monitoring | MetConnect |
| Classified fuel-handling area | WindObserver IS, subject to hazardous-area requirements |
| Temporary or portable monitoring | MaxiMet or WindObserver configuration selected for the application |
MaxiMet, MetConnect and WindObserver IS are not stated as accepted for AWOS surface wind reporting. Only WindObserver 70 carries that datasheet statement in the range.
The weather measurement only matters if the system can use it
Airport weather sensors may feed an AWOS, weather displays, airfield operational systems, runway monitoring, airport management systems, data logging and aviation communications systems. The required output and protocol should therefore be defined before selecting the instrument, using the product-specific documentation for the actual interface selection. A sensor that meets the physical requirement but cannot provide the required output is not a complete system solution.
A weather number needs a location, a timestamp and a reason to exist
Airport weather data is useful because it is tied to a known measurement location and operational purpose. For a wind reading, that means knowing where it was measured, at what height, which runway or operational area it represents, when it was measured, what the sensor reported and whether the data is valid. The sensor is part of the evidence chain.
The dangerous failure is not always no data
A missing measurement is obvious. A plausible but unrepresentative measurement can be harder to detect. A sensor installed in disturbed airflow, icing that degrades the wind measurement, the wrong model specified for a regulated application, a sensor in the wrong operational location, an output interpreted incorrectly, or certification assumed from the product family rather than the exact model all produce numbers that look reasonable. Airport weather systems need confidence in both the number and the conditions under which that number was produced.
So what weather sensors does an airport actually need?
An airport may need a combination of wind speed and direction sensors, temperature sensors, humidity and dew-point measurement, barometric pressure, precipitation measurement, visibility and cloud information, and runway-condition measurement. The exact combination depends on the airport’s operational requirements.
For surface wind reporting within an AWOS application, formal acceptance can determine the wind sensor choice. In the Gill range, WindObserver 70 is the model whose datasheet states FAA and CAA acceptance for that application. Elsewhere on the airport, the requirement may be more local and application-specific, making an integrated MaxiMet station, a modular MetConnect installation or another dedicated instrument more appropriate.
Eight questions before specifying an airport weather sensor
- What decision will the measurement support? Runway operations, AWOS, apron monitoring, de-icing, fuel handling or general estate monitoring.
- Which parameters are actually required? Wind, temperature, pressure, humidity, rainfall, visibility or others.
- Is formal acceptance required? If so, identify the exact acceptance and the exact model required.
- Where will the sensor be installed? Runway, threshold, apron, fuel area, building roof or temporary location.
- What will the surrounding environment do to the measurement? Buildings, masts, structures, jet activity and local airflow all matter.
- Can the sensor ice? If freezing conditions are expected, define how measurement availability will be maintained.
- What does the receiving system need? Output, interface, protocol and data rate.
- What happens when the sensor needs service? Access, replacement, calibration requirements and operational continuity.
Start with the operational decision. Work backwards to the measurement. Then specify the sensor.
Four things to remember
- Every measurement exists for a decision. The parameter list follows from what the airport has to decide.
- Wind sits unusually close to the operational decision. That is why acceptance can matter as much as accuracy.
- Acceptance belongs to a model, not a family. WindObserver 70 carries the FAA and CAA statement for AWOS surface wind reporting.
- Siting can matter as much as the sensor. A correct instrument in a disturbed airflow still produces an unrepresentative measurement.
Frequently asked questions
Airport weather systems can measure wind speed and direction, temperature, humidity, atmospheric pressure, precipitation, visibility, cloud information and runway conditions. The exact sensor network depends on the airport's operational requirements and the systems into which the measurements feed.
An airport weather station is a system of meteorological sensors and associated equipment used to measure environmental conditions relevant to airport operations. Depending on the application, it can include wind, temperature, humidity, pressure, precipitation, visibility and other measurements.
An Automated Weather Observing System can combine measurements including surface wind, temperature, pressure, humidity and visibility-related information, depending on the system configuration and applicable requirements. The exact sensor set and reporting requirements depend on the installation.
Wind speed and direction can affect runway selection and aircraft take-off and landing decisions, particularly where crosswind, tailwind and gust conditions are important. This makes the quality, availability, location and acceptance of the wind measurement particularly important.
Airport wind measurement can feed directly into aviation operational systems and therefore may have formal application-specific acceptance requirements. A general-purpose weather sensor may have excellent measurement performance but still not meet the acceptance or system requirements of a particular AWOS installation.
Gill identifies WindObserver 70 as the model whose datasheet states FAA and CAA acceptance for AWOS surface wind reporting. This statement should not be transferred to other WindObserver models without corresponding documentation.
No. WindObserver 70 is specifically the model whose datasheet states FAA and CAA acceptance for AWOS surface wind reporting. Other WindObserver models should not be assumed to carry the same acceptance statement.
The WindObserver 70 specification states a wind-speed measurement range of 0 to 70 m/s.
Yes. WindObserver 70 is a heated model. Heating is relevant where the operating environment can produce icing, but the requirement should still be assessed against the actual airport climate and installation.
WindObserver 70 uses stainless steel 316 construction and carries IP66 protection. These specifications address aspects of mechanical construction and environmental protection but do not by themselves establish aviation acceptance or suitability for every airport environment.
Yes. WindObserver 70 holds Lloyd's Register Type Approval. This is separate from the FAA and CAA acceptance stated for AWOS surface wind reporting and should not be presented as the basis for that acceptance.
The sensor needs to measure wind that is representative of the operational area rather than airflow disturbed by nearby buildings, structures or other obstructions. A sensor can meet its laboratory specification while producing an unrepresentative installed measurement if its location or mounting distorts the airflow.
The exact location depends on the airport layout, runway configuration, operational requirement and applicable siting rules. The sensor should be positioned to provide representative exposure while accounting for nearby structures, airflow disturbance, mounting requirements and any applicable obstacle or frangibility constraints.
An airport may use multiple wind measurement locations where runway length, runway configuration or operational requirements mean that one measurement point cannot adequately represent conditions across the relevant operational areas. The exact number and placement depend on the airport and applicable requirements.
Freezing conditions can cause ice to accumulate on exposed sensor components and affect measurement availability. Where icing is an expected operating condition, the wind-sensor specification should therefore address heating or another approved means of maintaining measurement availability.
A frangible mast is designed to break or deform in a controlled manner under specified impact conditions rather than creating the same type of fixed obstacle as a rigid structure. Where airport siting requirements place a sensor structure within relevant protected areas, frangibility can form part of the installation specification.
Airports may use compact weather stations or dedicated sensors for aprons, de-icing areas, construction zones, fuel facilities, solar installations and other estate locations. These applications may have different measurement and acceptance requirements from runway AWOS installations.
MaxiMet can provide integrated meteorological measurement where a compact station is required to measure multiple environmental parameters. The appropriate MaxiMet model depends on the parameters required and the installation conditions. It should not be assumed to have the same formal aviation acceptance as a dedicated AWOS wind sensor.
MetConnect provides a configurable weather-monitoring architecture where sensors may need to be separated or different sensor inputs incorporated into the system. It can be useful where a single compact integrated weather station does not suit the required installation arrangement.
Where the installation is classified as a hazardous area, the wind sensor must meet the applicable hazardous-area requirements. Gill's WindObserver IS is the intrinsically safe anemometer in the range and uses a certified interface in the non-hazardous area. The exact installation must follow the applicable certification and hazardous-area requirements.
WindObserver IS carries ATEX, IECEx and UKEX certification, and meets EN 60945:2002 for EMC. These certifications relate to the specified equipment and installation arrangement and should be checked against the current certification documentation.
No. WindObserver IS is unheated. This matters where icing is part of the environmental requirement, because hazardous-area certification does not automatically provide a solution for icing.
WindObserver IS does not carry the Lloyd's Register Type Approval held by specified WindObserver marine models. Its purpose is to address hazardous-area requirements rather than to provide the same marine classification evidence as those models.
WindObserver IS factory calibration is traceable to national standards, but individual calibration certificates are not available for this model. Where a project requires traceable calibration evidence, that requirement should be considered during specification.
An AWOS wind sensor is selected around the requirements of the surface-wind reporting system, including any applicable formal acceptance. A general airport weather station may instead be used for local environmental monitoring away from the runway and may require several parameters in a compact package. The two applications can therefore require different sensor architectures.
Not necessarily. Some parameters can be integrated into compact weather stations, while others require dedicated sensors or different installation arrangements. Wind, temperature, pressure, humidity and precipitation can be combined in some systems, while visibility, cloud and runway-condition measurements may require separate equipment.
Start with the operational purpose, then define the required parameters, installation location, environmental conditions, acceptance or certification requirements, interfaces and maintenance strategy. For wind measurement, also consider exposure, airflow disturbance, icing and whether the exact model carries the required aviation acceptance.
No. Sensor accuracy describes performance under defined conditions. The installed measurement can also be affected by siting, airflow distortion, mounting, icing, environmental exposure, configuration and data handling. Airport weather measurement therefore needs both an appropriate sensor and an appropriate installation.
No. WindObserver 70 is specifically the model whose datasheet states FAA and CAA acceptance for AWOS surface wind reporting. Acceptance should always be checked against the exact model and the applicable system requirement.
Provide the airport application, required measurements, intended installation location, expected wind and weather conditions, freezing or icing exposure, hazardous-area classification where applicable, required acceptance or certification, receiving system and interface requirements. These details allow the sensor specification to be matched to the actual airport application.
The questions that usually follow
How accurate does a wind sensor need to be?
Why accuracy is one requirement among several, and how to write a wind specification that means something once the instrument is installed.
Read the answerSpecifying and choosingWhat is the best wind sensor for harsh environments?
Salt, ice, vibration, dust and submersion each demand something different from the instrument. How to match a wind sensor to what the site actually does to it.
Read the answerSpecifying and choosingWhat should I consider when choosing a weather station?
Parameters, siting, outputs and maintenance decide a weather station choice. A practical route from the measurement requirement to a specific model.
Read the answerHave an application to discuss?
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