AN ASSESSMENT OF THE PRECISION OF THE OBSERVATIONAL DATA USED IN NEW ZEALAND'S NATIONAL CADASTRAL SYSTEM

AbstractMost of New Zealand's cadastral network has been converted from a paper-based records system to a fully integrated digital cadastral system known as Landonline. The complete data set contains in the order of 18 million "observations". This paper describes both the data quality issues that had to be addressed and the statistical analyses undertaken to assess the precision of these observations. Variance component estimation was used to determine the precision of the data which, as far as possible, have been grouped into homogeneous categories. It is concluded, firstly, that the precision of the input data generally exceeded the a priori estimates used; secondly, that historical observational precisions were lower than present day and, thirdly, that for any given time period, the bearings and distances used in the cadastral framework had similar precisions.