An Analysis of Airship Acceleration Dynamics for Airborne Gravimetry

Abstract : A Honeywell three-axis inertial accelerometer was placed on board a Skyship 600B and acceleration data were recorded during the flight. Weather conditions during the flight were windy and turbulent, considered to be near the upper limits of this airship's operational envelope. Power spectra were computed from the acceleration data and showed favorable fall-off at high frequencies, but high power at low frequencies, as compared to a large, multi-engine aircraft used for gravity surveying. The vertical component of the airship accelerations was used as the driving input to model the response of a mechanical, "zero-length spring" style gravimeter. The model shows that the meter would exceed its dynamic limits if it experienced the accelerations recorded on the airship. However, one commercially available gravimeter, the Bell BGM-5, has sufficient dynamic range to operate under these conditions.