Have you ever seen a surveyor peering through a camera like devise at the top of a tripod and wondered what he's doing? And what is his partner doing 20 feet away with that pole? Here's a quick explanation of that device, called a total station, and how it works.
You can find a wide variety of total stations and other surveyors' equipment at http://www.southernphoto.com/view_catagory.asp?CTGRY=1001. (PRWeb) February 10, 2007 -- Have you ever seen a surveyor peering through a camera like devise at the top of a tripod and wondered what he's doing? And what is his partner doing 20 feet away with that pole? Here's a quick explanation of that device, called a total station, and how it works.

A total station is a land-surveying tool used to accurately measure distances, architecture and geological land forms such as mountains. The device is extremely accurate, with some able to measure distances up to 0.1 millimeter or 1/1000 of a foot. Most surveyors don't need that much accuracy (which necessitates a higher cost out-of-pocket) and opt for a less expensive model accurate to 1 millimeter or 1/100 of a foot.

The total station itself looks a bit like a camera. You may have seen them mounted on a tripod -- they are often used at highway construction zones to measure the distance of an expansion, new on-ramp or other change to the traffic pattern. The standard unit includes a second piece attached to a pole.

This second piece is the reflector, and it is usually manned by a second surveyor. Matching the exact height of the total station relative to the reflector is extremely important to ensure accurate measurements, so often surveyors will do several trial runs before they note the points they're measuring. To aid in accuracy, the reflector point has a leveling bubble on its top, so that the person in charge of that end of the process can be sure the device is completely level.

Leveling the reflector is extremely important to ensure it matches the total station's height and gives an accurate distance reading that isn't skewed to the left or right, up or down.

Some newer total stations, including the Topcon total station, offer reflectorless measuring devices. These pinpoint an object using a scope in a view-finder chosen by the surveyor using the device. The Topcon total station then emits a modulated microwave or infrared signal that bounces off the target and back to the device, allowing it to measure distances out to about 1.5 miles (or 2 km).

Many Topcon total stations also include a GPS function, which allows measurements over greater distances but with less accuracy. GPS signals are still only accurate to about 2 feet.

You can find a wide variety of total stations and other surveyors' equipment at http://www.southernphoto.com/view_catagory.asp?CTGRY=1001.

About SouthernPhoto.com:
Southern Photo Inc. is a supplier of surveying equipment. We also offer repair and maintenance at our full service repair shop specializing in Topcon service and repair. In addition to surveying equipment and supplies, SouthernPhoto.com also offers drafting supplies and furniture and art supplies. For more information, visit http://www.southernphoto.com.

###