A computer simulation of a phased array imaging system has been written. The OTF of an imaging system with a specified number of annular apertures can be computed directly by a convolution if there are no phase aberrations. If phase aberrations are to be included (piston, two axis tilt, focus, and uncorrelated aberrations for each subaperture), the OTF is computed via the point spread function. A two-dimensional scene is created from elementary shapes and transformed to the spatial frequency domain by a two-dimensional fast Fourier transform (FFT). The spectrum is multiplied by the optical transfer function (OTF) and by a function which accounts for pixel size and shape. After being properly scaled by a radiometry analysis the scene is transformed back to the spatial domain. Pixel fluxes are then computed and Poisson noise and detector noise are added.