Coded aperture imaging using successive imaging of a reference object at different positions

In coded aperture imaging knowledge of the coded array pattern and its positional relation to the detector array is needed in order to be able to reconstruct the scene image. Usually a theoretical model of the coded array is used and the actual array needs to be aligned accurately with respect to the detector. The present invention uses a coded aperture imager to image a reference object in the scene and uses the intensity pattern on the detector array to determine the decoding pattern corresponding to the coded aperture array. The reference object may be a point source in which case the pattern on the detector array may be used directly as the decoding pattern or it may be used to correct a theoretical pattern for any misalignment.