An Introduction to Land Surveying

An Ancient Profession

Once humans began to form societies with fixed locations-abandoning their hunter-gatherer ways for good-it became important to more clearly define things like boundaries and property ownership. Historians cite the fact that the Egyptians created a land register more than 5,000 years ago, while others in the profession point to Babylonia as another culture obsessed with the concept of who owned what. Over time, the role of the land surveyor took on professional status-the Roman Empire needed to create a tax register of the lands it had conquered-and the spread of Islam throughout the Middle Ages saw Arabic surveyors invent a number of tools that provided an easier way to discern angles, alignment, and level ground.

What Does a Surveyor Do?

In today's world, the surveyor is involved in all aspects of design and construction. They work with engineers to set out the proper alignment of buildings, bridges, roads, tunnels, and other elements of infrastructure. They also work with mapping experts to help identify the exact location of landmarks. One of their major responsibilities is to determine boundaries between one person's property and another's, as well as to help create subdivisions when landowners decide to split up their holdings and sell them off piecemeal to individual buyers.

Land Surveyor Techniques

Land surveyors are generally concerned about three essential measurements-distance, angles, and elevation. Some combination of these elements is used to provide nearly every important derivative a surveyor will generate. The traditional method of determining distance involves using a chain or measuring tape of a known and highly precise length. When measuring the length of a property line, for example, one end of the chain is affixed to one corner of the property and stretched fully along the line. The far end is pinned down, after which the chain is rotated and extended further down that line. This process is repeated until the far corner is reached. Even in countries that eventually adopted the metric system, a surveyor's chain was traditionally 66 feet long and made up of exactly 100 links (each link, therefore, was 7.92 inches long). Conversion to meters is achieved by multiplying the resulting measurement by 20.1168. Angles were measured by means of a compass, while elevation could be determined through the employment of a barometric-type device that used air pressure to indicate height above sea level.

The Surveyor's New Toolkit

The computer age has changed the way land surveyors determine boundaries, although the results are the same-except now, they are much more accurate. Gone is the transit, the telescope-type device that allowed for the measurement of horizontal and vertical angles in the field; gone as well is the chain or tape. A device called a total station now does the bulk of the work. This is a fully electronic unit that computes angles and distances to a specific point by using microwaves or infrared signals bouncing off a prism that is held in the distance by a surveyor's assistant. Nowadays there are 'robotic' total stations that can be controlled remotely. This eliminates the need for the aforementioned assistant, as the operator himself holds the pole and manipulates the total station from afar. An entire industry has grown up around this process, with software design companies creating various programs to store, manipulate, and even transmit total station data. Many land surveyors carry into the field handheld devices that link directly to the total station-whether via USB cable or wirelessly through Bluetooth or similar technology-which then provide an instant mapping environment for the data being collected. By streamlining the process in this manner, land surveyors can supply the necessary information to a landowner or developer almost instantaneously, and with an amazing level of accuracy.

Articles
Introduction to Land Surveying | What Is Remote Sensing? | How an RTK Network Helps Surveyors | Cadastral Surveying | Aerial Photography

For more information please contact us.