Book Description

Gravity measurements from a high-altitude balloon were made in late September to verify global and upward-continued gravity models. The first flight was intended to provide balloon motion and environment data with a preliminary estimate of the quality of measured gravity values. A balloon operates in a dynamic, largely unpredictable environment; thus, the gravimeter senses accelerations due to balloon motions as well as gravitational acceleration. Independent measurements of balloon motions from an intertial navigation package (three accelerometers, three rate gyros, three-axis magnetometer and two tiltmeters) combined with ground tracking (X, Y and Z position and velocity) will allow for separation of balloon-induced accelerations from gravitational acceleration to 1 mGal, using tracking data to an accuracy of about 5 cm/sec in velocity for Eotvos corrections, and position to 1 m. This first engineering flight was planned to coincide with the lowest seasonal wind velocities over Holloman AFB, where AFGL has its permanent balloon launch facility. Mild wind velocities are desired to provide the most benign environment possible during the testing phase, and to keep the balloon within tracking range. The experiment design, launch, and flight operations, and a first look at the data are presented.