Weather balloon Weather balloon A weather or sounding balloon is a balloon (specifically a type of high-altitude balloon) that carries instruments aloft to send back information on atmospheric pressure, temperature, humidity and wind speed by means of a small, expendable measuring device called a radiosonde. To obtain wind data, they can be tracked by radar, radio direction finding, or navigation systems (such as the satellite-based Global Positioning System, GPS). Balloons meant to stay at a constant altitude for long periods of time are known as transosondes. Weather balloons that do not carry an instrument pack are used to determine upper-level winds and
Automated airport weather station than actual. Current sensors are capable of reporting visibility in a wide range. For aviation purposes, the reported values are rounded down to the nearest step in one of the following scales: Automated airport weather stations use a Light Emitting Diode Weather Identifier (LEDWI) to determine if and what type of precipitation is falling. The LEDWI sensor measures the scintillation pattern of the precipitation falling through the sensor's infrared beam (approximately 50 millimeters in diameter) and determines from a pattern analysis of the particle size and fall velocity whether the precipitation is rain or snow. If precipitation is determined to