What is theodolite?

and Theodolite is a device for measuring horizontal and vertical angles. The traditional theodolite consists of an observation tool that can be rotated horizontally and vertically and two calibrated circular plates, located to measure the amount of horizontal or vertical rotation in degrees. By placing an observation tool that can be a binoculars, it is possible to measure its horizontal and vertical angles with respect to suitable reference points. Normally it would apply to the north for horizontal angles and horizon for vertical angles. Theodolites are used in navigation and astronomy and are now most commonly used in exploration - either for construction and construction or in geographical surveys. By measuring the horizontal angle, due to the right north, the function from two different locations with a known distance apart, the distance can be calculated by trigonometry. Once the distance is known, the height can be determined in the same way by measuring the vertical angle of the element with respect to the horizon.

It is difficult to accurately identify the date when the first theodolite was introduced, because in the whole history a number of devices carrying different degrees of similarity with modern theodolite were introduced. The earliest recording of this type comes from approximately 150 BCE in ancient Greece; It was called dioptra and had two metal plates that could turn horizontally and vertically, along with the method of leveling the water containing pipes. It was used for astronomical observations. The term "Theodolite first appeared in 1571, when the English mathematician Leonard Digges described the tool for measuring angles called" Theolitus ". However, it seems that he measured only horizontal angles. In 1653, William Leybourn, an English inspector and author, provided a detailed description of theodolite that could measure angles horizontally and vertically and integrate compass and view.

Modern theodolites work on the same principles as their predecessors, but with improvement of accuracy and portability. Havetelescopic monuments and can measure angles with accuracy up to one tenth of a second of the arch. Electronic Theodolite often includes an infrared device for distance measurement and can have a processor and software for calculating and storing the results internally or downloading it to a laptop or PC. This type of system is sometimes called the "total station".