Abstract Frequencydomain airborne electromagnetic data usually have block errors, and the conventional method commonly uses the pseudo tieline semiautomated leveling method to solve this problem. This method needs to input many parameters, and the operators must have experience. This paper presents a pseudo tieline automatic leveling method. First, the 1D filter is used to filter out the high frequency mobile geological anomaly and get the median values including the values of background and leveling error. Through the derivation of the pseudo tieline, the mutation point interval statistical method is used to determine the mutation point position of the leveling border so as to divide the nonleveling region. In the direction of the pseudo tieline, a certain distance is extended from the border to determine the pseudo tieline. In this range, the median filter is used for the border mutation points, and then the background value is obtained in the range of pseudo tieline. The difference between the background value and the median value is used to obtain the leveling error, which is finally combined with the raw data results to obtain the leveling result. This method needs to input fewer parameters and can automatically divide leveling areas, thus greatly reducing the intensity of work and human errors. At the same time, it can effectively eliminate block errors and retain real geological anomalies.
|