ABSTRACT
A system using a helicopter, 30 to 70 knots, was perfected in the early 1970s, a slow flying airplane system, 80 to 130 knots, became available in the early 1980s, and an over water fast airplane system, 200 to 320 knots, was flown in the mid 1980s. This chapter presents data from surveys flown using the helicopter and slow fixed-wing system. Accuracies of these systems when compared to ground data are between 1 and 2 mgals. The first reported tests of airborne gravity measurements in the late 1950s and 1960 were feasibility trials. Available fixed-wing aircraft were used. Systems were installed consisting of marine type gravity meters, available photo-grammetric cameras and/or doppler radar for positioning and some unique hypsometers for vertical variation measurements. The basic aim of the test program was to create a helicopter-transported gravity and magnetic surveying system to be used for petroleum exploration.
