| 摘要 |
The present method involves the detection of variations of the direction of gravity from the mathematical model of the earth, which may be caused by the presence of a discontinuity in the earth's surface, with relatively heavy materials in the earth's crust causing a deflection of gravity toward such heavier material. In accordance with the present method an inertial system is mounted in a mobile vehicle and the vehicle is moved along a survey route from a first control point to a second control point, with the locations and the deflection from the vertical being known at the two control points. The vehicle is stopped periodically between the two control points in order to eliminate accumulate errors in the inertial system, and to record the position of intermediate points to the surveyed. At each of the stopping points the indicated position of the stopping points relative to latitude, longitude, and elevation are recorded, and additional inertial system parameters are recorded as required to determine the deflection of the vertical at each of the survey points. To avoid complex intermingling of errors associated with the inertial system with the change in the deflection of the vertical, the inertial platform is not releveled at each of the stopping points. When the vehicle reaches the second control point, the position indicated by the inertial guidance system is compared with the actual position of the second control point as to latitude, longitude, and elevation, and following the determination of errors, the position of the various intermediate stopping points are recalculated taking the overall error and the time at which each point was surveyed into consideration. Similarly, the error in the deflection of the vertical, which is separate from the error in position, is determined, and the deflection from the vertical of each of the intermediate survey points is then determined. The results of the survey may then be plotted on a map. |
