Determination of Geodetic Figure by the Differential Scale Factor Method and Their Error Evaluation

Abstract

Differential scale factor method in EDM was first introduced by WHITE (1973), and succeeding study was made by TANAKA (1978) in Japan. The present authors added to these studies a formula for evaluating the variance-covariance matrix of adjusted side-length, and made a field test observation in Iwase, a town in the Ibaraki Prefecture, Japan, The followings are main conclusions: (1) When the observations are carried out even under unstable atmospheric con-ditions, we can obtain reliable values that are very close to the one under normal atmospheric condition, (2) Standard deviations of the adjusted side-lengths are within range of several milimeters, and never exceed ten millimeters, (3) Some times we are obliged to get systematically, deviated values as compared with normal values, (4) This method is more suitable to estimate crustal shear strain, because under this method figure is more exactly determined than the size of the geodetic figure.