THE USE OF AIRBORNE LIDARS IN HIGH-PRECISION GRAVITY PROSPECTING (ON THE EXAMPLE OF EASTERN TRANSBAIKALIA)

Abstract

In the production of high-precision gravimetric studies at ore deposits, an important factor is the methodical correctness of the work, which directly affects the subsequent costs and life cycle of a geological exploration enterprise. It is known, that gravimetric survey, in addition to the actual stage of measurements on the ground, includes the stage of eliminating errors introduced into the measurements by external fields and objects, in particular, the terrain. Methods existing and adopted at the state level involve the use of materials from cartographic funds (topographic maps at a scale of 1:100,000 - 1:25,000 and larger). It is also allowed to use open (free) terrain models. These materials are distinguished by a common characteristic feature - the lack of detail in thedisplay of the microrelief and steep inclined surfaces (slopes, walls, faults, incisions). These elements have a significant effect on the field values, measured by gravimeters, especially when measurements, are taken at points located at a small distance from the specified forms. In addition, the existing methods do not involve calculations using digital elevation models built from initial data with a high density of elevations (with a step of a few meters or more). All this creates the prerequisites for an insufficiently complete consideration of corrections in gravimetric measurements. At the same time, the technical capabilities of modern aviation remote sensing equipment make it possible to quickly obtain a high-precision digital model of the terrain over large areas. The most accurate, versatile and promising technology in this respect is the method of airborne laser (lidar) scanning. In this paper, the authors consider a methodology for performing work using both airborne laser scanning of the relief and other types of data (topographic maps 1:25,000, open data models). As part of the research, calculations were also made of the final corrections for the influence of the terrain and a comparison of the results obtained with each other. With the help of mathematical modeling and cartographic algebra, matrices (grids) of design parameters were constructed. The results of the study are clearly demonstrated in diagrams and diagrams, substantiating and illustrating the high information content of the study