Every construction and surveying project depends on choosing the right method for the ground, the structure, and the accuracy required. A method that works for a flat building site may fail on a sloping riverbank, and a technique suited to a small renovation may be far too slow for a highway corridor. The practical approach […]
A land survey, sometimes called a property survey, records the official description, measurements, topography, and boundaries of a specific parcel. Surveyors also note the man-made features on the lot, including the house, garage, sheds, and buried utilities such as underground plumbing and electrical lines. Buyers and sellers most often commission surveys when a home changes
Distance measurement in surveying does not always require a tape, a wheel, or an electronic instrument. For reconnaissance work, rough checks, and field sketches, surveyors have counted their own steps for centuries, and a small class of instruments automates the job. A passometer is an electromechanical device that counts the number of paces a person
GIS, or geographic information system, is a computer program that manages data. A GIS in surveying is an information system built around geographic or spatial information, which means every record in it is tied to a position on the earth. The field has grown quickly because it joins graphical features, such as parcel boundaries, roads,
Traverse comes from a Latin word meaning “passing across,” and that is exactly what a traverse survey does: it passes across the ground as a connected series of measured lines. Surveyors record the length of every line with a tape or chain and the direction of every line with a compass or theodolite, building a
The total station is the workhorse of modern surveying. It combines a digital theodolite for angle measurement, an electronic distance measuring device, and a microprocessor with memory in a single instrument, so one person can capture angles, distances, and coordinates without moving between tools. Surveyors use it for topographic mapping, construction layout, boundary work, and
Levelling is one of the most important parts of surveying before the start of any construction work. Roads, dams, canals, railways, buildings, and bridges all need known heights before the first excavation, because a slab, a pipeline, or a road bed has to sit at the correct level. This article covers the types of levelling
A curve in surveying is a geometric arc inserted into an alignment to change direction or gradient gradually instead of abruptly. Roads, railways, canals, and pipelines all depend on curves, because a sudden change of direction at speed is unsafe and a sudden change of grade is uncomfortable. Surveyors lay out these curves in the
Linear measurement is the most fundamental observation in surveying. Before any angle can be located on the ground, the length of at least one line has to be measured, because angles alone cannot fix the position of points. In plane surveying, the distance between two points means the horizontal distance; when the points are at
Leveling measures the elevation of ground points relative to a reference datum, and it is usually carried out as a separate procedure from planimetric survey work. The operation comes down to measuring a vertical distance against a horizontal line of sight, which needs a graduated staff and an instrument that can project a truly horizontal
