Reconnaissance Flights
The dark brown line on the small map marks the 1998 version of Saudi Arabia's claims regarding its boundaries with Yemen, Oman, the United Arab Emirates and Qatar.
Theodolite
The theodolite is an instrument that measures vertical and horizontal angles precisely. With stadia lines etched on the reticule of its telescope and the appropriate stadia rod (a flat-faced rod graduated vertically, its subdivisions corresponding to one/one hundredth of the focal distance) it will measure distances with accuracy sufficient for third order triangulation.