A new technique is described for image formation using a circular array of transducer elements in which each element acts as both a transmitter and receiver. By processing the amplitude and phase measurements acquired in such a system in a particular way, it is shown that it is possible to approach the performance of a transmit–receivefilledcircular aperture of the same dimension. The technique combines a synthetic aperture scheme with an earlier approach for array pattern synthesis ( J2synthesis). The proposed technique does not require spatial incoherence of reflections from the object plane, which was a severe limitation in earlier use ofJ2synthesis. The effect of array sampling with a finite number of transducer elements is also examined.