Total Station

Land Surveying is one of the oldest professions in the world. The first land surveys date back to nearly 3,000 years ago, when Egyptian Surveyors subdivided the fertile land around the Nile River and worked on re-marking the land after the annual flooding of the Nile River.

The early settlement of Australia also required help from Land Surveyors. The majority of famous early explorers including Burke and Wills had a Surveying background and their work allowed the land to be settled, by defining property boundaries in the city and the country. Back then Surveyors used primitive technology including chains and steel bands, which made their measurements difficult to record and often required the use of logarithmic tables and slide rulers.

We depend on Surveying to ensure order in the physical world around us. Surveyors play an integral role in land development, from the planning and design of land subdivisions through to the final construction of roads, utilities and landscaping.

Surveyors are among good company, working closely with their peers in the fields of engineering, architecture, geology and planning. Their role underpins these industries; Surveyors are the first people on any construction site, measuring and mapping the land. These primary measurements are then used by architects to understand and make the most of the unique landscape when designing and engineers to plan structures accurately and safely, ensuring buildings not only fit with the landscape but are able to be constructed.

Most modern total station instruments measure angles by means of electro-optical scanning of extremely precise digital bar-codes etched on rotating glass cylinders or discs within the instrument. The best quality total stations are capable of measuring angles to 0.5 arc-second. Inexpensive "construction grade" total stations can generally measure angles to 5 or 10 arc-seconds.

Measurement of distance is accomplished with a modulated infrared carrier signal, generated by a small solid-state emitter within the instrument's optical path, and reflected by a prism reflector or the object under survey. The modulation pattern in the returning signal is read and interpreted by the computer in the total station. The distance is determined by emitting and receiving multiple frequencies, and determining the integer number of wavelengths to the target for each frequency. Most total stations use purpose-built glass corner cube prism reflectors for the EDM signal. A typical total station can measure distances with an accuracy of about 1.5 millimeters (0.0049 ft) + 2 parts per million over a distance of up to 1,500 meters (4,900 ft).