Method and apparatus for regional gravity surveys

摘要

Method and apparatus for conducting regional gravity surveys, comprising a gravimeter module suspended below a helicopter and adapted to be lowered to the earth's surface for generating gravimeter readings. The gravimeter module includes an automatic reading gravimeter sensor and a mechanism for self-levelling of the sensor. A ground contact sensor is provided for determining when the gravimeter module contacts the earth's surface as a result of being lowered thereto and for determining when the gravimeter module ceases contacting the earth's surface as a result of being raised therefrom. The ground contact sensor generates a time marker indicative of these events. A GPS receiver is mounted in fixed relationship with the helicopter for generating periodic position coordinates. A system is provided for receiving and recording the subsurface gravimeter readings, the periodic position coordinates, and the time marker on a common time base. The system further includes circuitry for calculating the position coordinates of the gravimeter module when the gravimeter module contacts the earth's surface and when the module ceases contacting the earth's surface, by means of interpolating between respective values of the periodic position coordinates at the generated time markers.