1) Analyze aerial photographs in order to detect and interpret significant military, industrial, resource, or topographical data.2) Calculate latitudes, longitudes, angles, areas, and other information for mapmaking, using survey field notes and reference tables.3) Check all layers of maps in order to ensure accuracy, identifying and marking errors and making corrections.4) Compare topographical features and contour lines with images from aerial photographs, old maps, and other reference materials in order to verify the accuracy of their identification.5) Compute and measure scaled distances between reference points in order to establish relative positions of adjoining prints and enable the creation of photographic mosaics.