1. Optical Frequency Standard Joint Services Electronics Program (Contract DAAB07-74-C-0630) David E. Pritchard We are trying to develop a simple and economical "frequency meter" to be used with a tunable laser to preset the laser frequency, measure the laser frequency, or provide frequency marker pulses when the laser frequency is swept. A prototype system capable of 50 MHz accuracy is nearing...

We have discovered a "counter-jet" in the radio galaxy Cygnus A. This follows the earlier achievement, with Perley of the National Radio Astronomy Observatory (N RAO), of the discovery of the relativistic jet that emanates from the active galactic nucleus (a discovery that was made through their new methods of image processing at the the Very Large Array (VLA) at NRAO). A related project, a det...

This research is directed toward transforming a speech signal into a new speechlike signal that is perceived as identical to the original signal in all respects except that it is articulated at a rate different from that of the original speech. Such a technique is of interest in a variety of applications including learning a second language, developing talking books for the blind, generation of...

The central theme of our programs has been to advance the understanding of optical and quasi-optical communication, radar, and sensing systems. Broadly speaking, this has entailed: 1) developing system-analytic models for important optical propagation, detection, and communication scenarios; 2) using these models to derive the fundamental limits on system performance; and 3) identifying and est...