Modern topographic devices and electromagnetic waves: impact on accuracy of measurements

Precision topographic work is done by the means of classical instruments such as highprecision levels, theodolites and distance-meters. This method gives accuracy results of ±2 mm in altimetry and better than ±5 mm in planimetry, but it requires a lot of expenditures and a long time of execution and more staff. Nowadays, the constellation of the GNSS satellite positioning system and the improvements to electronic tachymeters can provide solutions to gaps in auscultation using conventional measurements. However, these methods also present their weaknesses, resulting by this way from their uses under the high voltage lines. The study of the influence of electromagnetic waves on high-voltage lines on topographic devices allows observations made with a GNSS receiver to be made from an electronic station or total station or with the aid of optical-mechanical theodolite to analyse and interpret the quality of the data obtained on the ground in the Maria Gléta zones in the municipality of Abomey-Calavi and Araromi in the municipality of Sakété. This makes it possible to present the effects of high voltage cables on these measurements and the determinations made in topometry. Very important on measurements at the GNSS receiver and at the total station, the actions of the electromagnetic waves evolve with the variation of the temperature.