Maps, drawings and surveying
In highway surveying work the plan produced will be drawn from measurements made in two dimensions which form the horizontal plane, but surveying generally is divided into two branches; geodetic surveying and plane surveying. There are some five types of drawings commonly used in highway work. These are ordnance survey maps, plans, longitudinal sections, transverse sections and detail drawings. The purpose of a longitudinal section is to show the height or the elevation of the ground along a line which is the centre line of proposed highway. A theodolite ‘traverse survey’ consists of measuring the angles between successive traverse lines and then finding the lengths of these lines. The Global Positioning System (GPS) is founded on space-based microwave technology and its primary use was for military purposes as a global navigation system. The full constellation of satellites is in place, and the GPS system will ultimately dominate the survey equipment field.