An electrooptical radio spectrograph

The electrooptical radio spectrograph is presented as a sensitive way to record the spectrum of a relatively wide frequency range with high resolution in both time and frequency. It takes advantage of the high recording density of photographic film and the high data rates of coherent optical processing systems. An instrument is described which records the spectrum over a 100-MHz frequency range. It has a frequency resolution of 130 kHz with low "sidelobe" response, good sensitivity, and a time resolution of up to 50 ms. Some of the applications of the instrument to radio astronomy are described.