Desenvolvimento de um sistema de calibração horizontal para sistemas de nivelamento digitais

Abstract

With the advancement of technology, digital leveling systems have replaced the mechanical optical levels in various application, mainly due to the efficiency and automation. These systems are basically composed of a digital level and an invar barcode leveling rod, where the precision of the observations are related to the rod scale, as well as the devices in the levels, for example the CCD sensor and the system of lenses. Over time, either by wear or due to damages that these devices may suffer, the scale of the level (function of the elements that form the equipment) and the rod may change, degrading the result of the observations. Thus, in order to achieve and guarantee precision, the instruments must be checked and calibrated simultaneously in laboratory, allowing the evaluation of the influence of the system components on the measurement result. In recent years, several structures were built for the simultaneous calibration of digital leveling systems in several countries and was called vertical or horizontal comparators. However, in the researched bibliography, no evidence was found in Brazil about the investigation and construction of these systems, thus, are proposed in this study the adequacy of an existing calibration structure in Geodetic Instrumentation Laboratory (LAIG) of the Federal University of Paraná (UFPR), to transform it into a horizontal calibration system, and a new methodology for the calibration process is proposed. As results were discussed and presented all phases of the design and construction of the accessory for adequacy of the horizontal calibration system are discussed and presented, as well as the factors that may influence the observations are analyzed. In addition, seven different digital leveling systems were calibrated, where their respective performances and scaling factors were derived. Such investigations indicated the potentiality in the proposed calibration process, whose results are comparable with the systems used foreign. Finally, calibration certificates of the analyzed systems were generated and the application of these certificates was investigated in the results of the observations of two first order differential leveling, applied to the monitoring of structures and a first-order geodetic network, located at the José Richa Governed Hydroelectric Plant (UHGJR) and at the UFPR polytechnic campus, respectively. It should be noted that from the calibration of the digital leveling systems it is possible to know the behavior of the instruments, quantifying the errors and achieving more reliable results due to the application of the calibration certificate. This is an official document that provide the user to meet the obligations and duties related to quality standards.