Utilização de espelho de reflexão frontal aliado ao nivelamento geométrico para determinação de desnível de pontos em ambientes confinados

The purpose of this work is to evaluate the use of a geodetic level along with a plain mirror of frontal reflection to aid the definition of height differences in confined environments. To achieve this, a mathematical model based on the principle of level (instrument) rectification was defined. The model consists of determining the tilts applied to the mirror in order to project the readings on the levelling rod to a horizontal plane common to all readings. To evaluate this model a series of experiments was conducted and the feasibility of the proposed technique could be proven. However errors with magnitude up to 12 mm were found, voiding the technique for first order levelling. Such errors could be associated to modelling the mirror's attitude and a deeper study is required. The technique may be used for third order levelling.