Position resection and intersection in the context of Geopositioning

A total station or total station theodolite is an electronic/optical instrument used for surveying and building construction. It is an electronic transit theodolite integrated with electronic distance measurement (EDM) to measure both vertical and horizontal angles and the slope distance from the instrument to a particular point, and an on-board computer to collect data and perform triangulation and position resection and intersection calculations.

Robotic or motorized total stations allow the operator to control the instrument from a distance via remote control. In theory, this eliminates the need for an assistant staff member, as the operator holds the retroreflector and controls the total station from the observed point. In practice, however, an assistant surveyor is often needed when the surveying is being conducted in busy areas such as on a public carriageway or construction site. This is to prevent people from disrupting the total station as they walk past, which would necessitate resetting the tripod and re-establishing a baseline. Additionally, an assistant surveyor discourages opportunistic theft, which is not uncommon due to the value of the instrument. If all else fails, most total stations have serial numbers. In the United States the National Society of Professional Surveyors hosts a registry of stolen equipment which can be checked by institutions that service surveying equipment to prevent stolen instruments from circulating. These motorized total stations can also be used in automated setups known as "automated motorized total station".

The bombing of the Chinese embassy in Belgrade, also known in China as the May 8th incident, occurred May 7, 1999, during the NATO bombing of Yugoslavia, when a US B-2 Spirit dropped five Joint Direct Attack Munition satellite-guided bombs on the Embassy of China, Belgrade, FR Yugoslavia, killing three Chinese journalists and injuring twenty-seven others. According to the US, the intention had been to bomb the headquarters of Yugoslav weapons importer Yugoimport, 440 meters south on the same street. President Bill Clinton apologized for the bombing, claiming it was an accident.

Central Intelligence Agency director George Tenet later testified the bombing was the only one in the campaign organized by his agency, and that the CIA had "miscalculated" the Yugoimport coordinates from its address. The Yugoimport building was later bombed but remains standing as of 2019. The US claimed its own map and satellite imagery analysis approved the target while failing to identify it as an embassy. Although extensively referenced as a NATO mission and aircraft, all B-2 strikes were targeted and flown under United States European Command alone. One CIA officer was fired following an investigation.

In surveying, triangulation is the process of determining the location of a point by measuring only angles to it from known points at either end of a fixed baseline by using trigonometry, rather than measuring distances to the point directly as in trilateration. The point can then be fixed as the third point of a triangle with one known side and two known angles.

Triangulation can also refer to the accurate surveying of systems of very large triangles, called triangulation networks. This followed from the work of Willebrord Snell in 1615–17, who showed how a point could be located from the angles subtended from three known points, but measured at the new unknown point rather than the previously fixed points, a problem called resectioning. Surveying error is minimized if a mesh of triangles at the largest appropriate scale is established first. Points inside the triangles can all then be accurately located with reference to it. Such triangulation methods were used for accurate large-scale land surveying until the rise of global navigation satellite systems in the 1980s.