Using random walk for on-line magnetic surveys

摘要

Data acquisition in geophysical field surveys usually needs a staked grid of measurement stations (Parasnis, 1986). The data point density does not vary throughout the field and does not take into account whether anomalies are present. Therefore the idea arose to develop a survey system to sample the field data adapted to the specific problem and process the data on-line in the field. Samples are not taken on pre-defined equally spaced lines or grids but on random walk paths. An efficient geomagnetic survey system is presented, which avoids separate geodetic measurements by using a Global Positioning System (GPS) in combination with a magnetic system. The data is sent to the survey computer via radio links for on-line monitoring which offers the possibility of adaptive data sampling in the exploration area of interest. Fast on-line algorithms for triangulation and anomaly detection have been developed using original, non-gridded data points.