Specification for linear measuring instruments for use on building and civil engineering constructional works. Steel measuring tapes, steel bands and retractable steel pocket rules

1966 ◽  
Keyword(s):  
Civil Engineering ◽  
Measuring Instruments ◽  
Linear Measuring

scholarly journals EARTHWORK VOLUMETRICS WITH UNMANNED AERIAL VEHICLES: A COMPARATIVE STUDY

2020 ◽  
Author(s):  
Raid Al-Tahir ◽  
Travis Barran
Keyword(s):  
Comparative Study ◽  
Data Acquisition ◽  
Unmanned Aerial Vehicles ◽  
Civil Engineering ◽  
Image Acquisition ◽  
Road Construction ◽  
Measuring Instruments ◽  
Total Station ◽  
Aerial Vehicles ◽  
Acquisition Costs

The recent evolution of Unmanned Aerial Vehicles (UAVs) as measuring instruments has become attractive for many surveying applications in civil engineering including the volumetric computations of earthworks in the construction of a highway. The application of softcopy photogrammetry to UAV acquired imagery has the potential to reduce data acquisition costs, time and with suitable accuracy for earthworks mapping and volumetrics. Their performance, however, is not well understood for these applications. This investigation tests the ability of the UAVs and photogrammetric software to generate volumes for the layers of material used in road construction, as well as to analyse their accuracies and limitations. Specifically, this study assesses the feasibility of UAV-based surveying in generating volumes for general earthworks in highway/road construction. Additionally, the study compares the performance of UAV-based surveying to that of Total Station surveying. Performance is evaluated along the required time for image acquisition and generating the final products, the required personnel and overall cost of survey. A segment of the Churchill Roosevelt Extension to Manzanilla was used in the assessment.

Concept of a new PZT

1978 ◽  
Vol 48 ◽  
pp. 271-278
Author(s):  
Chr. Kühne
Keyword(s):  
Mirror System ◽  
Measuring Instruments

The PZT according to MARKOWITZ, undoubtedly one of the most accurate measuring instruments, has become an integral part of astronomy in the last years. Yet there are two reasons why I still tried to improve the MARKOWITZ basic idea.For the MARKOWITZ process the use of a lens objective is imperative. Because of the diameter limitations of the lens objectives the magnitude is reduced. Although a 65 cm PZT has been put into operation in Washington recently, the thermal difficulties encountered made it necessary to control the temperature actively. In addition, the 65 cm diameter of a lens equipped with 4 elements can be considered as the very limit, but not for a mirror system.In addition there are still more disadvantages using lens objectives. The useable field is restricted by astigmatism, reducing the range of declination. The transmission, especially in the blue wavelengths, decreases very rapidly with the thickness of lenses. For large multilens objectives the transmission is less than for a mirror system.

Sex Crimes and Civil Engineering

1993 ◽  
Vol 38 (5) ◽  
pp. 499-500
Author(s):  
Harvey A. Hornstein
Keyword(s):  
Civil Engineering ◽  
Sex Crimes
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