Journal of Surveying Engineering

Current law and land‐use regulations encourage the use of alternative energy resources and protect the rights of those who adopt them. Access to sunlight has geometric and property rights components which pose new challenges to the surveying profession. Solar access surveys for site‐analysis and collector positioning are presented. A case study is given in which maps of predicted shadows were prepared for a homeowner whose windows were to be shaded by proposed construction.

Small space trilateration nets in which distances are measured between points can be likened to structural space frameworks in which elastic members are manufactured and joined together by pins. Accordingly, structural programs used for structural analysis can be used to adjust trilateration nets. Program STRUDL is used to illustrate the procedure. The preparation of data as input is discussed in detail. The output directly yields the distance corrections and the variation of coordinates of the new points. Two numerical examples are given.

Orthometric heights can be obtained without leveling by combining gravimetrically determined geoidal heights and ellipsoidal heights derived from Global Positioning System (GPS) interferometry. The accuracy of the orthometric heights is dependent on the accuracy of each of the two components. The paper discusses and compares different methods of geoid determination and evaluates their accuracy. The analysis shows that in areas well‐covered by gravity data, the determination of geoidal height differences is currently at least as accurate as the determination of ellipsoidal height differences by GPS‐phase measurements. Thus, orthometric height differences in these areas can be obtained by this method with an accuracy of 2 to 3 ppm. This opens interesting possibilities for orthometric height determination in the mountains and in remote areas without vertical control. Results from two test areas confirm this analysis. A brief discussion of the requirements for an accuracy of 0.3 ppm concludes the paper.

Good maps are required for the efficient and effective conduct of municipal planning and engineering. In spite of the rapid changes that have taken place in surveying and mapping technology, maps of the scale, accuracy, and precision required for sound municipal planning and engineering are lacking in many communities. As the principal technical advisor to local government, the municipal engineer bears the responsibility for the status of mapping within the community and for the adequacy of such mapping to meet the dayto‐day needs of municipal planning and engineering functions. This paper reiterates, within the context of the recent interest in computer mapping and related integrated data banks, the basic principles involved in mapping for municipal planning and engineering purposes. The paper describes the types of maps required for municipal planning and engineering applications, discusses the scales and contour intervals required, and describes the type of survey control network on which the maps should be based. Examples of the application of maps to municipal planning and engineering are given, together with examples of derived maps.

In 1984–1985 the Crescent, a multiuse building complex in Dallas, Texas, was constructed in a fast‐track scheme which employed many unique applications of field computers, as well as several unusual construction surveying techniques. The methods by which engineering control was maintained, and the coordination of those controls within the cartesian and polar grid systems employed, were new to the contractor, and required an unusually different approach to building engineering.