[Doc Ewen looks into the horn antenna, 1950]
Image courtesy of Doc Ewen


Harvard Cyclotron: 1948-1951

Detection of HI Line: 1951

Harvard 24ft and 60ft and NRAO founding: 1952-1956

1950s and 1960s: Two Roads that Crossed

Microwave & Millimeter Wave Applications in the 1970s and 1980s

Mm Wave Radiometry in the 1990s

May 2001 visit to NRAO Green Bank



[Doc Ewen and horn antenna, 2001]
Image courtesy of Doc Ewen

Doc Ewen: The Horn, HI, and Other Events in US Radio Astronomy

by Doc Ewen, © 2003

Millimeter Wave Radiometry in the 1990s: RAVIN-SL5 slide 7

[RAVIN-SL5 temperature calibration unit]

The RAVIN-SL5 temperature calibration unit (TCU), mounted on the RF head. The TCU is a unique feature of the RAVIN-SL5 radio telescope. It allows direct calibration of the recorded antenna temperature while observing a target. The TCU is controlled directly from the telescope control panel. A three position switch allows selection of the target signal, the ambient temperature, or an automatic repetitive sequence between the target signal and ambient temperature. It is particularly useful for rocket plume measurements during the launch phase, since it provides a direct measurement of the sky noise background temperature over the extent of the launch profile, prior to launch. When used with the remote focusing unit (RFU), it provides a direct measure of aperture focusing and efficiency, using the moon as a target. TCU and RFU capabilities are essential to the accumulation and analysis of short term phenomena, typical of rocket launches and kinetic kill events. Credit: Photo courtesy of Doc Ewen.

Modified on Tuesday, 07-Jun-2005 16:43:28 EDT by Ellen Bouton