Augmenting shift-and-add with zero-and-add

Abstract

It is explained how the recently invented zero-and-add technique for processing speckle images (short exposures of objects viewed with large telescopes under poor seeing conditions) can conveniently compensate for ghosts generated by shift-and-add imaging. The several steps in the associated data and image processing are illustrated with the results of operating on an ensemble of computer-generated speckle images. It is suggested how speckle data might be gathered and processed in such a manner that the overall signal-to-noise ratio would be significantly improved, over what can be achieved conventionally, without introducing much extra experimental complication.