In surveying, free stationing (also known as resection) is a method of determining a location of one unknown point in relation to known points. There is a zero point of reference called a total station. The instrument can be freely positioned so that all survey points are at a suitable sight from the instrument. Setting up the total station on a known point, often it is not possible to see all survey points. With the total station, bearings and distances are measured to at least two known points of a control network. This with a handheld computer recorded data is related to local polar coordinates, defined by the horizontal circle of the total station. By a geometric transformation, these polar coordinates are transformed to the coordinate system of the control network. Errors are distribu