pilot balloon


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pilot balloon:

see weather balloonweather balloon,
balloon used in the measurement and evaluation of mostly upper atmospheric conditions (see atmosphere). Information may be gathered during the vertical ascent of the balloon through the atmosphere or during its motions once it has reached a predetermined maximum
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Pilot Balloon

 

a small rubber balloon filled with hydrogen and released in free flight to determine wind velocity and direction at different altitudes or to establish the altitude of the lower boundary of clouds. The pilot balloon ascends at a nearly constant speed, calculated according to the lifting force and the weight of the balloon envelope. The altitude of the balloon is determined as the product of the vertical speed and the time between the moment of release and the moment of recording. The wind velocity and direction at different altitudes are computed according to simultaneous readings of the altitude of the balloon and the angles (elevation angle above the horizon and the azimuth) observed through an aerological theodolite.

pilot balloon

[′pī·lət bə‚lün]
(engineering)
A small balloon whose ascent is followed by a theodolite in order to obtain data for the computation of the speed and direction of winds in the upper air.

pilot balloon

A small rubber balloon filled with hydrogen or helium. It ascends at a uniform and known rate (i.e., 500 ft/min). A theodolite tracks the balloon, and the wind velocity is thus determined at various levels.
References in periodicals archive ?
Cuff], the tube was secured based on distension of the pilot balloon during repeated gentle finger palpation at the suprasternal notch (3).
This method of fixing the inflation line enabled us to attach the pilot balloon, which served as a visual indicator of the reinflated cuff.
Produced in response to a Department of the Army Operational Need Statement, the one-man portable Miniature Observation Kit consists of one Kestrel Pocket Weather Tracker (see Armada issue 4/2003 page 104), a Lighted Survey Master--which is a dual-function instrument incorporating a direct sighting compass and inclinometer -and miniature helium tanks with 100 28-cm pilot balloons.