Topographic mapping is the process of presenting a map to get an overview of the shape of the earth’s surface and the features in it, both natural features (rivers, lakes, coastlines, etc.) and artificial features (roads, bridges, buildings, etc.). In general, topographic mapping is used to map conditions above the ground surface. Topographic mapping can be used to generate contours, volumes, situation details, long sections and cross sections.
Topographic mapping usually required to initiate construction planning, land boundary mapping, detailed situation mapping, stockpile volume survey and other needs. The topographic map will contain information on position, altitude and orientation direction. There are several methods that can be used in topographic mapping, including the following.
The terrestrial method is a method of direct positioning by measuring angles and distances as well as the height of objects on the earth’s surface. This method usually uses a set of Total Station measuring tools. To carry out measurements in this method, every measuring instrument used must be visible to each other. The data generated from this method is a collection of the values for the position of the X, Y and Z coordinates of the measured object.
The GPS (Global Positioning System) method is a method of determining the position of points carried out by observing objects in space, in this case, the GPS satellites. Measurement or mapping in this method uses geodetic GPS. Measurements between GPS do not need to be visible to each other, what is needed is to be able to “vicible” the satellites so that measurements can be made in a longer distance. The accuracy of the data generated using this method can reach millimeters orde. This method is commonly used for setting up benchmark (control points). For topographic mapping we use GPS-RTK Method (Real-Time Kinematic).
Utilization of UAV (Unmanned Aerial Vehicle) technology has been commonly used in recent years. This technology can be used for survey and mapping purposes. Mapping using UAV is a mapping method that can cover a large area at an affordable price. This method is combined with geodetic GPS to provide accurate positioning. The output that can be generated through this method is a photo mosaic, orthophoto, DSM (Digital Surface Model), DEM (Digital Elevation Model) and DTM (Digital Terrain Model). For special case in the mining operation, aerial mapping can be use to calculate the stockpile volume and update mining operation situations periodically.