Abstract: An apparatus and method are disclosed for reducing electromagnetic or acoustic energy scattered in both the near and more generalized vicinity of a source thereof by various phenomena including atmospheric and weather-related effects and diffraction at the top edge of heretofore known barriers. The apparatus includes a member configured for engagement with the top edge of a barrier, with the member having a patterned edge defining a plurality of portions jutting away from the top edge of the barrier and in a direction having a component toward the source, preferably substantially in a more or less horizontal plane with the top edge.

Abstract: An acoustic apparatus (10) adapted for use as either a sound projector or a ound receiver. The apparatus (10) comprises a bundle (20) of individual sound tubes (21, 22) disposed in a tube array unit (14) which rests on a support unit (13) operatively engaged with an acoustic unit (11). Only the ends of the individual sound tubes (21, 22) are provided with a plurality of spaced discrete sound ports (25).

Abstract: A quad disk static pressure probe apparatus (10) including: a hollow stem member (15) having a plurality of static pressure ports (16) disposed on its periphery; an apertured collar unit (14) surrounding the stem member (15) and being in open fluid communication with the static pressure ports (16); and, inner (21) and outer (18) pairs of disk members operatively secured to the stem member (15) above and below the location of the static pressure ports (16).

Abstract: An acoustic capacitor of minimum size and minimum susceptability to temperature-induced internal pressure change. The capacitor comprises an insulated container having an internal member of high heat capacity material surrounded by a porous thermally conductive material; the member acts as a heat sink, slowing the rate of change of pressure due to change in ambient temperature. The internal pressure that is built up due to temperature change is bled off by the same orifice that equilibrates the internal pressure to ambient atmospheric pressure.

Abstract: A method and apparatus for measuring the speed of a gas stream, particula suitable for use in detecting wind speed, utilizes the gas flow to create a negative pressure across a pressure sampling port oriented with its axis substantially perpendicular to the gas flow, the negative pressure being created by accelerating the gas flow stream lines over a surface of revolution containing the port. The negative pressure is compared with a reference pressure by means of a pressure transducer whereby the transducer output is representative of the speed of the gas. In a preferred form, the apparatus comprises a first pressure probe in the form of a sphere mounted on a tube projecting axially from a hollow cylindrical cup-like member with the sampling port formed in the base of the sphere and the cup-like member forming a second pressure probe with a pressure tapping internally of the cup providing the source of reference pressure.