Contributions to Radar Tracking Errors for a Two-Point Target Caused by Geometric Approximations

: Expressions for the exact range and angular errors between the apparent (measured) and actual location of a two-point target are obtained. The difference between the exact errors and two distinct sets of approximation to them are examined as a function of the ratio of the distance from a monostatic radar to the centroid of the scatterers. One set approximations to the errors is found in the literature and is apparently the far field supposition of parallel line propagation paths between points on the target and the radar's aperture. The other set results from expanding appropriate parts of the exact errors in infinite series about the aforementioned ratio and then truncating the various series. The advantages and shortcomings of each set of approximations are identified. The exact expression for the angular error is shown to reduce to both approximations when certain assumptions are made; however, such is not the case for the transverse and radial range errors.