SAR defocussing resulting from uncompensated beam steering errors.

摘要

A synthetic aperture radar achieves fine cross-range resolution by coherently processing received pulses of energy, a phase error in the pulse will result in a degradation in resolution. Uncompensated external factors, i.e. thermal or plasma layers, will induce a beam steering error which directs the antenna beam in a direction other than the desired, thus inducing a phase error in the pulse.;This thesis evaluates the impact a beam steering error has upon image fidelity (i.e. cross-range resolution and image pixel location) for squinted beam imaging radars.;Three types of imaging radars are examined: (1) Real Aperture Radar, (2) Unfocussed SAR, (3) Focussed SAR. The three systems are evaluated with and without a beam steering error in order to assess the impact of the error.;The focussed SAR is evaluated for two different aperture lengths and multiple look SAR performance, to reduce image speckle, is also examined.