The authors present concepts and show simulation results for a number of situations where the ISAR (inverse synthetic aperture radar) image is degraded by errors introduced by the signal acquisition and data processing. These errors result in degradation of resolution, false targets in the image, geometric distortion of the image, incorrect values for the scattering center RCS (radar cross section) and a raising of the background noise floor. Results from the proposed model are useful in describing the degradation due to the following: errors in measuring rotation angles or frequency steps; phase errors in the incident illumination that are dependent on frequency or rotation angle; variation of the response of target scattering elements over rotational angle; linear or vibrational translation during target resolution; and the geometric distortion arising from the 3-D-to-2-D transformation in the imaging process. >