iMETOS VWS - METOS by Pessl instruments


  • Calculated sensor variables equal to iMETOS IMT300 sensor set: wind speed, solar radiation, soil temperature, air temperature, precipitation, relative humidity and leaf wetness, along with calculated values of ET0, vapor-pressure deficit (VPD) and DeltaT.
  • All data and decision support services are accessible online through FieldClimate.


Virtual stationiMETOS IOT Stations
VariablesSame parameters as iMETOS IMT300 + soil temperatureBased on sensor set
AvailabilityAnywhere in the worldOnly where the station is installed
TerrainNot complex terrainAny terrain
MaintenanceNo maintenanceRegular hardware maintenance necessary
Suitability for high value decisions (frost, water management, disease modelling etc.)LimitedHigh


With actual case studies Virtual Weather Station is under continuous improvements.

Seven different environmental parameters have been validated at more than 50 different iMETOS stations worldwide during the last 1 year period, by analysing the accuracy of virtual data coming from meteoblue with Pessl Instruments sensor readings.

In particular air temperature, relative humidity, solar radiation, wind speed, soil temperature are considered on an hourly basis and precipitation, leaf wetness on daily basis since the timing of an event can change quickly.

Results show that air temperature on an hourly basis has mean absolute error MAE <1.5K, relative humidity <10 %, wind speed <1.5 m/s and daily precipitation <2 mm.


The following measures have been defined to run statistical analysis of all the data.

  • MAE (Mean absolute error) measures the average magnitude of the errors in a set of data, without considering their direction.
  • MBE (Mean bias error) is an indicator of whether the model is over-predicting or under-predicting the measured values.
  • RMSE (Root mean square error) is a quadratic scoring rule which measures the average magnitude of the error. This means the RMSE is most useful when large errors are particularly undesirable.

*Click on the picture to enlarge it

The 2 m air temperature is well modelled by the meteoblue Learning Multi-Model (mLM) with values of MAE < 1.2 K. Relative humidity shows a MAE<10% in most of the stations and the model tends to underestimate RH. The model uncertainty of the wind speed is 1.5 m s-1.

The model skill of daily precipitation events decreases with increasing precipitation intensity. In fact, MAE results to be less than 2 mm, but in some stations located in the tropics the variance becomes bigger. Here precipitation results unpredictable as it is only caused by thunderstorms. Simulations can thus predict well the trend like e.g. a drier or moister week but hard to tell the exact amount and when. Leaf wetness and soil temperature variables result to have discrepancy in most of the stations. As expected the accuracy of soil temperature is worse than the accuracy of the air temperature. MAE values are between 1.5-9K.

The Virtual Weather Station allows manual adjustments of local rain data if needed. The user can use a small rain gauge to measure actual rainfall and then correct data in FieldClimate. Manually adjusted rainfall data provides more accurate results on the water balance.

Air temperature
Relative humidity
Solar radiation
Wind speed
Leaf wetness
Soil temperature


  • You have a large field with one central iMETOS station and want weather information for remote parts of the same field, with minimal cost.
  • You depend on specific weather conditions and want to receive frost alarm, disease modelling and data to make temperature-based decisions, but don’t want to spend too much on a real weather station.
  • You already have an iMETOS station and want more weather information than what the station offers, such as virtual sensors for wind speed, solar radiation, rain gaps, soil moisture and leaf wetness, along with the services for work planning, water management (ET) and disease models.
  • Want to get familiar with smart farming but don’t want to purchase an actual weather station at this point (cooperatives, farmers, farmers groups)
  • You are a farm implement dealer who wants to give your clients a glimpse of additional premium services with virtual field data.
  • You are an irrigation dealer who wants to offer clients Irrimet -ET based irrigation scheduling.
  • You work for media or local municipality and want to support the general public with weather information and local forecast (using Pessl Instruments API for weather based local services).
  • You are a telecom company and want to offer premium weather forecast package services to your clients.
  • You need weather record-keeping and extreme local weather events for SmartCity and logistic enterprises.

    Not sure if this device is the right one for you? Do you have a specific, technical question?
    Contact our product manager and get your answers first hand.

    Davide TABARELLI
    Product manager, Weather forecast & Hardware


    *Ask the expert is meant for technical questions only. If you have a question regarding the order process, pricing, shipping, etc., please contact our commercial department