The paper presents a suggestion of modification of Otrebski' s theorem for some special structures of geodetic networks. The modification leads to forming up the conditional equation system with unknowns. A new parameter as a global criterion of evaluation of the quality of the networks characterized by an inhomogenous observation system, has been introduced as well.

The author presents a concept of a method of remote determination of temperature along a sight line of surveying instruments. It has been assumed that the environment influences a laser beam propagated in space; as a result of this influence the laser beam is distorted and weakened. It has been decided to make advantage of such situation and to read information concerning the medium of light beam propagation from the change of the structure of the laser beam. The paper presents a laboratory method of readouts of atmospheric factors of the air from images of the face of the laser beam. Initial experiences have been promising and confirmed assumptions made by the author.

A new solution of the resection is presented in this paper. Two methods of position determination have been developed. An indicator of possibilities of position determination has been introduced. Cases when the position cannot be determined have been considered and their geometric interpretation has been developed.

Spline functior.s play an important role in many technical applications. The paper presents some potential possibilities of their application in adjustment of railway tracks as a versatile tool of track axis approximation. Methods of determination of cubic interpolating and approximating splines are presented in detail. Splines are easily determined and they have satisfactory co□ verge□ce to the desired curve.

Automatic generation of DEM based on image matching technique is an important part in digital photograrnmetry. DEM has been found widely in practical applications as in the fields of surveying, civil engineering, road design, agriculture, military, etc. For large DEM project, accuracy, efficiency, and economy are the three main factors to be taken into account. Accuracy is the first important factor to be considered. The effect of modeling methods on DEM accuracy have been tested. The characteristics of terrain surface are considered as a difficult and traditional topic in generating of DEM. Terrain surface may be open or covered with different objects. For generation of accurate DEM, objects on terrain surface must be detected and filtered. There are many methods for detecting and filtering objects which have been found on the terrain surface. Some of them are basing on mutual location of measured points along definite profiles (geometric analysis) or on images converted. This article presents formulas for automatically detecting and filtering covered objects on the base of the geometric analysis of measured points mutually located along determined profiles in X and Y-direction.