REFRACTION INFLUENCE ANALYSIS AND INVESTIGATIONS ON AUTOMATED ELIMINATION OF REFRACTION EFFECTS ON GEODETIC MEASUREMENTS

B. Böckem, P. Flach, A. Weiss, M. Hennes

Abstract

Refraction effects are generally caused by an inhomogeneous propagation medium for the optical beam and are recognized as today’s major source of systematic errors in the precise optical determination of angles and distances. Because meteorological point measurements do not deliver satisfactory correction values, the investigation of alternative methods motivated the development of a dispersometer, a metrological solution with a very sophisticated instrumental set-up. Furthermore, the compensation of deterministic refraction effects basing on atmospheric scintillation is envisaged: Optical scintillation measurements with a scintillometer or with CCD-sensors yield line averaged turbulence parameters of the atmospheric surface layer, which can be used for determining the refractive index gradient. Because CCD-sensors are implemented in today’s high-end surveying instruments, automated on-board-solutions will be possible.

Keywords

refraction, angle measurement, direction transfer, dispersion, dispersometry, scintillation, scintillometry, image analysis

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IMEKO-WC-2000-TC14-P358.pdf

DOI

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IMEKO TC

TC14 - Measurement of Geometrical Quantities

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