INVESTIGATIONS FOR THE DEVELOPMENT OF AN EFFICIENT METHOD OF HEIGHT CONTROL EXTENSION BY STEREOMETER MEASUREMENT

Abstract

Various methods of spatial aerial triangulation are available for photogrammetric control extension. However, all these methods require the use of costly first order triangula-tion instruments or precise comparators and electronic computers. Methods requiring simple_ equipment are available only for plani.-. metric control extension. For height control extension, however, there are few equally simple methods, Vicek's method is the only promising .one.. For small establishments who could not afford to equip their, organizations with costly first order, . triangulation instruments or ccnparators and computers, simple methods like these would be of great use. The height control extension. method suggested by Meek needs only simple instruments like a stereoscope and a parallax bar. However, Vlcek's investigations .were limited to a strip of seven models onlya So it was proposed to carry out further investigations on the method and to arrive at definite conclu.• sions regarding its accuracy, feasibility etc. Chapter I of.. this thesis is introductory, and emphasizes the need for developing purely height control_ extension _ methods. Chapter II gives the details of Vicek's method followed by a critical discussion. Chapter III gives the details , of the inves-tigations carried out by the author and the results. The analysis of results is given in . Chapter IV which also incorporates the conclusions. It can now be definitely stated that Vicek's method of height control extension is sufficiently accurate even for first order photogrammetric work,