BorealScat gets a weather station

One of the primary goals of the project is to study the variation of forest radar signatures in different environmental conditions. This is necessary since boreal forests are subject to highly dynamic (and sometimes extreme) weather conditions, affecting synthetic aperture radar images taken from satellites. Examples are wind-blown trees causing Doppler shifts in the reflected radar signals and wet soil causing strong reflections of signals off the ground. Several meteorological instruments and soil moisture sensors have therefore been installed by FDS Mätteknik on and around the tower at the BorealScat site.

The following parameters are measured:

• Air temperature, moisture and pressure
• Soil temperature and moisture
• Wind speed, direction and acoustic virtual temperature 
• Precipitation (rain or snow)

A solar shield containing the temperature/humidity probe at tree top height. An identical sensor is placed at ground level.

Two 3D ultrasonic anemometers are mounted at the top of the tower for measuring wind speed and direction with minimal turbulence from the tower. Ultrasonic anemometers, which do not have any moving parts, were chosen to perform reliable wind measurements all year round with minimal maintenance. They are also heated to avoid the build-up of ice.

The tipping bucket raingauge which works for all forms of precipitation. An internal heater, activated at 1°C, melts snow that collects in the bowl.