This is basically an automated version of the traditional weather station. The reasons behind the automation are actually not very clear, maybe it was to save on human labour or just make it easier to get information from remote areas, but we all know that automation of things in our life today has worked very well to make our lives easier and much more convenient.
A typical automatic weather station (AWS) will come with an enclosure that is weather proof and that houses the meteorological sensors, an optional telemetry, rechargeable battery and a data logger. It will also come with a wind turbine or solar panel attached to it and will normally be mounted onto a mast. Each system will normally have a specific configuration depending on the purposes for which it is intended. With this system, you have the option of having the information stored and reported at a later date or having the information reported in real time. With real time reporting, there will need to be the Global Telecommunications system and the Argos system; through which the reporting will be done. Previously, one had to place the AWS where there was presence of communication and electricity lines but things have really changed today and the mobile phone technology, wind turbine and solar panel are making it possible to have wireless stations that function without connections to the electricity power grid lines.
Mostly the AWS will come with the following instruments:
- A thermometer used in measuring the weather
- An anemometer that is used in measuring wind speed
- A wind vane that is used in measuring wind direction
- A hygrometer for the measuring of humidity
- A barometer for the measurement of the atmospheric pressure
- A Ceilometer that is used in the measuring of cloud height
- Visibility sensor and/or a sensor for present weather
- A rain gauge that is used in the measuring of rainfall or precipitation that is liquid-equivalent
- For the measurement of snow depth, the ultrasonic snow depth sensor
- For the measurement of solar radiation, the pyranometer
The manual stations usually have the capacity to report the amount and class of clouds available in the sky. The AWS cannot however do the same. Accuracy with precipitation measurements can also be an issue as the gauge is usually required to empty itself out in between observations; this is particularly for snow measurements. The AWS is also not in a position to measure all-weather elements that do not touch the sensor such as for patches. There is really no way for the system to observe weather conditions that do not touch the sensor. These are simply some of the issues that have been raised on the transition from the manual stations to the AWS.
The data logger can simply be described to be the heart of the entire AWS. It is what records all the information that is being recorded by all the various instruments contained within the station thus it is a very important tool. It is possible for this logger to actually be tailor made to suit the needs of a particular client but this is only made possible in the very high quality systems. A large number of the general data loggers that are available in the market will not meet to the letter the specific meteorological requirements of a certain client such as protection from sand, sandy air, humidity, animals among other factors, communication, inputs and power consumption. This is what necessitates the custom making of the data loggers for specific clients in line with their specific needs. The loggers serve some very vital functions which include:
- The collection and archiving of information from each sensor within the system
- The processing of the collected meteorological data for the users
- The storage of all the data collected within the system; the storage usually takes place either on a USD card or in the logger’s memory.
- The management of the power supply of the entire system
- It also manages all the communication protocols taking place within the remote server. The various communication protocols mostly used within the system include RS232, uSD, WiFi, RTC, GPRS and GSM