Abstract: Provided is a collapsible antenna formed of one or more generally planar and vertically inclined inflatable panels. According to the invention, each of the panels has a continuous outer wall, a continuous inner wall and a plurality of web partitions extending between the inner and outer walls to form a series of tubular members. The inner wall of the collapsible antenna is at least partially covered by a metallic material and a plurality of dipole elements are affixed to the web partitions and spaced from the inner wall in a predetermined relationship such that the antenna will operate at a preselected frequency when inflated.

Abstract: A radar system for subsurface inspection comprising a short pulse transmitter, an antenna for radiating signals to and receiving external reflections from the surface and from below the surface being inspected, a receiver connected to the antenna for generating an output signal in response to the external reflections, and a clutter cancellation circuit for eliminating internal reflections developed in the system to prevent interference by such internal reflections with the desired external reflections to enhance the system detection capability and reliability of evaluation of such external reflections. Clutter cancellation is accomplished by storing the internally generated clutter and subsequently subtracting it from each incoming radar range sweep consisting of surface and subsurface signals plus unwanted clutter.

Abstract: Apparatus for the detection of buried objects comprising a broadband, high resolution short pulse transmitter and a bistatic or monostatic noncontacting antenna for radiating the transmitted signal through the ground for reflection from a buried object, a sampling type receiver which reduces the bandwidth and center frequency of the received signal, and a locking circuit controlled by the first reflection from the ground or soil surface to thereby lock the range sweep to the soil surface and eliminate the effects of antenna height variations.