Pilot balloon

PILOT BALLOON A small balloon whose ascent is used to determine the direction and speed of low level atmospheric winds. Also known as a pibal.

Pilot Balloon A small balloon whose ascent at a constant rate is followed by a theodolite in order to obtain data for the computation of the speed and direction of winds at various levels in the upper air above the station.

Pilot Balloon
(Abbrev. PIBAL)- A small helium-filled meteorological balloon that is tracked as it rises through the atmosphere to determine how wind speed and direction change with altitude.
Pilot Report ...

pilot balloon observation (commonly called PIBAL)—A method of winds-aloft observation by visually tracking a pilot balloon.

pilot balloon (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 ...

PIBAL: Pilot Balloon.
PIREP: Pilot Report.
PPI: Planned Position Indicator. Radar Scope.
"R" ...

Rabal A method of winds aloft observation essentially the same as a pilot balloon observation except the height data is derived from the radiosonde observation rather than from assumed ascension rates.

THEODOLITE An optical instrument used to track the motion of a pilot balloon, or pibal, by measuring the elevation and azimuth angles.

However, during twilight it may be impossible to use the ceiling projector and then a pibal (pilot balloon) light may be used. This is a simple flashlight bulb attached to a battery.

For example, in upper air measurements and observations "rabals" (radiosonde balloons), "pibals" (pilot balloons), and "pireps" (pilot reports) are used to determine the strength and direction of winds aloft.

Surface winds are measured by anemometer and wind vane; winds aloft by such systems as pilot balloon, radiosonde, or aircraft navigational techniques.

Topic: Meteorology