The World Meteorological Organisation (WMO) guideline no.8 defines the measurement requirements for weather stations. The WMO also defines stringent measurement requirements for a standards compliance weather station, called a Tier 1 weather station. For example, the WMO specifies that all wind measurements must be made at a height of 10 metres, which makes the installation inconvenient.
General-purpose weather stations, which do not fully comply with the WMO guidelines, are called Tier 2 weather stations. For Tier 2 weather stations some compromises were made for convenience. For instance, wind speed and direction may be measured at a height of 2 metres rather than specified 10 metres.
As a general rule, weather authorities may have a base set of Tier 1 weather stations which are quite expensive, and they also have a second set of Tier 2 weather stations to supplement measurements or may be used on a short term/project by project basis. For special purposes, for example, a mine site/port facility would typically install a Tier 2 weather station, rather than a fully compliant Tier 1 weather station.
There are also some consumer-grade / hobby store weather stations which may provide interesting inaccurate weather data to home users however these are usually not calibrated and the data cannot be relied on.
Unidata’s Weather Stations have a broad range of applications depending on your choice of configuration and instruments. When considering a weather station purchase, most customers will decide to set up a Tier 2 weather station. Customers then have the choice of using a specialised instrument for each measured parameter or a modern multi-parameter instrument, like the Vaisala WTX536 weather transmitter or Lufft WS800-UMB smart weather sensor.
Modern multi-parameter weather stations use ultrasonic technology and are very convenient to install and maintain as they do not have moving parts. Please see a typical parameter list from the 6501V Vaisala Weather Transmitter below:
1. Wind Speed – Average
2. Wind Speed – Maximum (Gust)
3. Wind Speed – Minimum
4. Wind Direction – Average
5. Wind Direction – Maximum
6. Wind Direction – Minimum
7. Rainfall
8. Rain Duration
9. Rain Intensity
10. Hail
11. Hail Duration
12. Hail Intensity
13. Barometric Pressure
14. Air Temperature
15. Relative Humidity
16-23. Derived channels – e.g. running totals, min, max, average
One of our simplest weather stations consists of a temperature and humidity sensor mounted in a double louvred radiation screen and connected to a Neon Remote Logger that is mounted in a weatherproof enclosure.
A weather station more often required, includes instruments that enable you to monitor and record temperature, relative humidity, global solar radiation, wind speed and direction. These instruments are then integrated with Neon Remote Logger. Neon Remote Logger will measure, store and transfer weather data using either cellular, LoRa or various satellite networks. Collected data is sent to a central Neon server to be analysed and displayed on a standard web browser.
On the right are some examples of typical weather station screen displays from the Neon Application Software.
Installing telemetry enabled datalogger reduces the need for time-consuming site visits and gives assurance that the weather station is continuing to operate correctly without the need for a site visit.
Other aspects to consider, when designing weather stations, are instrument enclosures, mounting and external power supply.
Unidata offers a wide range of weatherproof, UV stable, IP67 or higher rated enclosures that come with weatherproof connectors which allow for simple plug and play weather station installation. Typically, our customers choose to mount weather station enclosure and instruments on a fixed pole but we can also supply a pole with a tripod base for installations that will not be permanent.
Remember that the instruments you add to weather stations increase the power burden. Solar panel, battery and solar regulator power system is regarded as an essential part of Unidata weather stations. Any other form of external power that is available on the site can easily be integrated as well.
