Crook, C.N. 1988 A study of Mekometer data acquired by the Earth Deformation Section of the Geological Survey. Lower Hutt: New Zealand Geological Survey. New Zealand Geological Survey report EDS 118 52 p.
Abstract: The Kern ME3000 (Mekometer) was used by the New Zealand Geological Survey for most of the distance measurements in its deformation monitoring programme between 1980 and 1985. In this time over 1200 measurements were made for deformation studies, and over 350 extra measurements were made to calibrate the Mekometer. Also there were more then 470 tests of the Mekometer frequency. These data have been compiled in order to seek systematic errors in the data, to determine the most appropriate corrections to apply, and to estimate the resolution of the data for measuring deformation. During each deformation survey each line is usually measured twice. Systematic errors can be estimated by correlating the differences in the corrected lengths of lines with the corresponding differences in the possible sources of errors (such as instrument temperature). Using this method, statistically significant errors are found which depend on the instrument temperature and the time of day. Errors depending on atmospheric pressure are not significant. The temperature dependent errors are estimated as 0.13ppm/deg.C in the long range measuring mode and 0.33ppm/deg.C in the short range measuring mode. Corrections could not be reliably estimated for the time dependent error, which could be as great at 3ppm. The Mekometer data can be expected to resolve engineering shear strains of 3-4ppm on most of the Geological Survey's monitoring patterns. (auth)
