Utility asset layers are usually only accurate in relation to the cadastre they are positioned against (relative accuracy), but are inacurate in absolute terms because the cadastre itself is inacurate (i.e. absolute inacuracy).

With the advent of readily and cheaply available global positioning systems the absolute accuracy of the digital cadastre is improved, but the relative positioning of other layers is no longer within acceptable error margins.

The Spatial Adjustment Manager (SAM) and the Spatial Adjustment Engine (SAE) largely automates the positional improvement of both the digital cadastre and the utility assets.

The above image shows the Storm Water and Original Digital Cadastre running through the buildings shown in the high resolution orthophotograph. When the orthophotograph is compared to the Survey Accurate Digital Cadastre there is excellant correlation, which is an excellant indicator that both have good absolute position, i.e. they are very close to their true position.

This SAM Demonstration CD will take you through the processes of moving the spatially dependant layers such as Council Assets, Utilities, Annotation Layers and Zoning Layers to the more accurate position relative the Survey Accurate Digital Cadastre.

Please refer to the "White Paper" prepared by Spatial Web Consulting for further reading on the process.

Please refer to the "Article" on using Occupations found in High Resolution Orthophotography to improve the positional accuracy of a Digital Cadastre and spatially dependant layers such as Utilities, Assets, Annotation Layers and Zoning Layers.