The function 'Combined Cartesian' is to calculate and plot the coverage of one or more fixed Units to a defined (single) mobile Unit. As a result of the calculations, all plots are merged and presented as a overlay on the current picture. If required aditional analysis can be done on the coverage results which are presented as a overlay on a picture.

As the radial type of result from 'Polar Coverage' cannot easily be processed afterwards 'Combined Cartasian' coverages use a raster. The coverage of each unit in the analysis is produced in a raster.

A raster is a rectangular area with a fixed reolution. Because of this, raster calculations can be perfomed on the different rasters.

There are a number of different aspects to the operation of this feature which are shown in the following chapters.