The ability to obtain simultaneous active and passive millimeter wave images using a common antenna has numerous DOD as well as commercial applications. Radiometric and radar images are not new, nor are simultaneous passive and active images of a common scene. The feature that is unique to the radarometer concept is simultaneous use of the same antenna by a radar and a radiometer, operating in the same frequency band at a nominal pixel scanning rate of 1,000 per second. The radarometer sensor is capable of operating in both the passive and active modes either individually, in time sequence, or simultaneously. The radarometer uses a common high-speed mechanically scanned antenna aperture capable of generating active and passive millimeter wave images simultaneously. The important feature of the radarometer design that allows simultaneous active and passive operation in the use of an RF diplexer which separates the signals associated with the radar and radiometer modes. The typical frequency separation displacement is 5 GHz, at a nominal operating frequency of 95 GHz. The results of measurements performed on an engineering test unit will be described.

Date Published: 14 July 1999
PDF: 12 pages
Proc. SPIE 3703, Passive Millimeter-Wave Imaging Technology III, (14 July 1999); doi: 10.1117/12.353008

Published in SPIE Proceedings Vol. 3703:
Passive Millimeter-Wave Imaging Technology III
Roger M. Smith, Editor(s)