### Abstract:

The application of the least squares adjustment techniques to the
area of surveying has been considered and two computer programs
called HCONTRL and VCONTRL are developed for horizontal and vertical
control respectively. The principle of least squares is discussed
in chapter II. The observation and condition equations are compared
and the observation equations technique is applied in the programs.
The general forms of the observation equations for distance and
angle (or direction) are derived in chapter III. The solution and the
precision of the solution from the least squares adjustment technique
are also discussed. A brief discussions on future systems; the satellite
positioning, the inertial positioning, and the non-classical
method, are included in chapter III. In chapter IV, the development and the procedures to be used in
using the computer program HCONTRL are discussed. The least squares
application to the various techniques of the horizontal position control;
traverse, intersection, resection, triangulation, trilateration,
and combined networks, are described in chapter V.
The theory of vertical position control is discussed in chapter
VI where techniques of direct leveling and trig leveling are described.
This chapter also includes a brief description on; gravimetric leveling,
barometric leveling, hydrostatic leveling, tacheometric leveling,
satellite altimetry, and steric leveling. The development and procedures
of the computer program VCONTRL, to adjust the direct leveling
and the trig leveling by the least squares technique are discussed in
chapter VII. The application of the least squares to the direct leveling
and the trig leveling is given in chapter VIII. In chapter IX,
practicality of the least squares adjustment is considered.
The summary and conclusions are in chapter X. Appendix I consists
of the numerical examples of the least squares adjustment of
the various techniques in the horizontal position control by the computer
program HCONTRL. The numerical examples of direct leveling and
trig leveling by the computer program VCONTRL are given in Appendix II.
A numerical example of the gravimetric leveling computation to find
the geopotential numbers is also presented in Appendix II. Appendix
III contains the complete listings of the computer programs HCONTRL
and VCONTRL.