Absolute determination of the vertical gradient of gravity

Abstract

This paper reports an absolute determination of the vertical gradient of gravity. The result is believed to be the first to achieve a precision comparable with those generally obtained with relative gravity meters. From measurements of time and distance down the trajectory of an object in free fall made with the commercially available absolute gravity meter FG5-202, two new data-processing algorithms were used to determine a gradient of (220.8 ± 2.8) µGal m-1 and (221.3 ± 3.0) µGal m-1 at Membach in Belgium (1 µGal = 10 nm s-2). These results are consistent with the values between 206.6 µGal and 226.5 µGal m-1 found at Membach using relative gravimetry.