A System for Airborne Measurement of Vertical Air Velocity

Abstract

A system which measures vertical velocity of the air from an aircraft is discussed and evaluated. Basically, the vertical air velocity system (VAVS) utilizes an incidence vane, vertical accelerometer, and computer-directed high-accuracy vertical gyro to measure and display vertical air velocity in real time. This technique is found to have several advantages over computational techniques which use aircraft response to estimate vertical air velocity. The VAVS is compared in a formation flight with the vertical air velocity output from a system employing an inertial navigation system (INS) mounted on an NCAR Queen Air. Spectral density plots for the VAVS and INS agreed well with each other for wavelengths from 2 km to 150 m. Also shown is a representative VAVS data output from penetrations of a cumulus cloud during the 1976 HIPLEX program.