Method of correction of magnetostrictor errors

Translated from Izmeritel'naya Tekhnika, No. 1, pp. 35–38, January, 1989.     

Integration of multivariate measurements for the correction of cross multiplicative systematic errors of measuring systems

Optimal estimates of a set of measured values that make it possible to reduce the influence of random and cross multiplicative systematic errors of measuring instruments are discussed.     

Path-radiance correction by polarization observation of Sun glint glitter for remote measurements of tropospheric greenhouse gases

High-accuracy remote measurement of greenhouse gases is hampered by contamination of the field of view by the path radiance of solar radiation scattered from clouds and aerosols. A method is proposed for eliminating the effect of path radiance by differentiating two components of polarized light. The polarization of path radiance is measured directly at the wave-number region of strong water-vapor absorption. Using this measurement, we eliminate the components of path radiance involved in other bands, which are used for greenhouse gas measurements, by differentiating two components of the polarized light. It is shown that the effect of path radiance on retrieving the column amount of gases potentially can be reduced to below 0.1%.     

Computed tomography postacquisition data correction for systemalignment errors

A critical issue in obtaining high-quality images from a computed tomography system is the mechanical alignment of the data acquisition system. This paper will compare two methods of measuring and correcting errors introduced into second-generation computed tomography data sets from misalignment of the system. Both of these methods use a projection data set from a complete scan of an object as a starting point. One method is an iterative method that looks at residual errors in selected portions of the reconstructed image. The other method requires that the centroids of the projection data coincide with the centroid of the object. It will be shown that the centroid registration algorithm can be used to accurately measure a number of important computed tomography system alignment parameters and is mathematically efficient. The residual error algorithm will be shown to give less satisfactory results     

Calculation of errors in strain-gauge measurements

Conclusions In many instances when measuring strains in components with a low tensile stiffness (plastics, reinforced rubber, etc.), it becomes necessary to take into account the possible errors due to the stiffening effect of strain gauges over their glued area.This error can be accounted for by applying the deformation distortion coefficient whose value can be determined from (11). For the practical application of this formula it is necessary to know the stiffness W of strain gauges as well as the elasticity constants of the component. The stiffness of strain gauges can be determined by a simple method, described in the article.     

E-field assessment errors associated with RF dosemeters for different angles of arrival

In this paper, an analysis of the surface electric field on a human body based on finite-difference time-domain simulations is presented. A statistical analysis of the dosemeter interaction with the human body has been made by means of the variations of the relative orientation of the human body from the RF source. Variations of the RF source frequency have also been made, by comparing three different services FM, GSM-900 and DCS-1800. Three different scenarios have been simulated where the angle of arrival of the main RF contribution impinges on the human body with a certain probability. Despite the differences between the scenarios, the variations in the electric field strength at each frequency are negligible where the dosemeter would be located.     

Statistical analysis of errors in gravimetric measurements

Statistical analysis of the results of gravimetric measurements made with GAL gravimeters are used to show that samples taken at two-minute intervals form a stationary time series with zero autocorrelation. We show that the distribution function for gravimetric readings is considerably different from a normal distribution. Translated from Izmeritel'naya Tekhnika, No. 7, pp. 3–5, July, 1997.