a small balloon (diameter c
(pibal) A balloon that ascends through the atmosphere at a constant rate and is tracked by a theodolite in order to obtain timed data for the computation of the wind speed and wind direction at various levels in the upper air above the station. The balloon is brightly colored to provide contrast with the background sky or clouds.
A small balloon whose ascent is followed by a theodolite in order to obtain data for the computation of winds aloft.
Originally a small hydrogen-filled balloon released to show the direction a full-sized balloon would drift. Pilot balloons can be tracked by theodolite to find the wind velocity aloft. To see a picture and description of a theodolite, visit our Instrumentation page.
A small observation balloon for the purpose of measuring wind velocity and direction. Also known as Pi-bal.
A small balloon whose ascent is used to determine the direction and speed of low level atmospheric winds. Also known as a pibal.