USA As Represented by Secretary of the Navy

Johns Hopkins University

Cornell University

Paul A Bernhardt

Joseph J Suter

Michael W Nurnberger

Andrew Nicholas

Matthew J Reinhart

David L Hysell

Chuck Hoberman

James M Cloeren

A method and apparatus uses a VLF transmitter, a VLF receiver, and/or a low earth orbit satellite including a rocket engine. A VLF wave transmitted into space is converted to an ambient wave. The ambient wave acts as a signal wave for a whistler traveling wave parametric amplifier. Rocket exhaust is generated in atmospheric plasma. The rocket exhaust includes kinetic energy acting as a Lower Hybrid wave source. The Lower Hybrid wave source produces a Lower Hybrid wave, which acts as a pump wave for the parametric amplifier. Nonlinear mixing of the signal wave and the pump wave in the atmospheric plasma simultaneously parametrically amplifies the ambient wave and generates an idler wave and a parametrically amplified wave. The parametrically amplified wave (1) reduces the density of energetic protons or killer electrons in the Van Allen radiation belt, and (2) improves communications between the VLF transmitter and VLF receiver.

Rocket exhaust driven amplification (REDA) of VLF waves in space

An apparatus for interfering with and canceling electromagnetic reflections from a conducting object such as a solid or hollow conducting sphere. The reflection of an incident electromagnetic wave from a conducting sphere can be reduced or cancelled by placing a polyhedral conducting mesh (PCM) around the conducting sphere. The incident EM wave induces electric fields in the region between the conducting mesh and the internal conducting sphere. These induced electric fields may interfere with and in some cases may completely cancel the incident EM wave and thus reduce reflection. The PCM can be tuned to reduce or cancel reflection of incident EM waves at one or more specific frequencies.

Apparatus for radar target cloaking using polyhedral conducting mesh

A high frequency signal calibration target deployable in outer space includes an expandable and electrically conductive symmetric structure. The structure may mechanically expand from a stowed configuration to a deployed configuration. Scatter of high frequency signal off of a substantially symmetric signal calibration target may be measured to accurately calibrate systems using high frequency signals.

Expandable signal calibration target

An improved RF beacon for use in space/earth communications and positioning determination provides better spectral purity and frequency stability. A power supply provides regulated voltage and control signals to the beacon. Each of two oscillators operate at a slightly different frequency very near the aforementioned 16.7 MHz. The slight difference provides for a frequency selection with respect to the transmitter frequency spectra. The oscillator provides a signal to a plurality of multiplier circuits. The resulting multiplied frequency signals are fed to respective amplifiers. Some of the features of the radio frequency beacon include redundant switchable oscillators, a 1067 MHz signal having data modulation capabilities, the ability to change power levels, improved frequency stability and temperature control characteristics, and a triplexer to optionally combine the three outputs into a single port.

Radio frequency beacon

A rotational hyper-spectral imager is disclosed. The rotational hyper-spectral imager collects substantially all available photon flux emitted by an object being detected and analyzed and allows the rotational hyper-spectral imager to determine the composition of the objects. The rotational hyper-spectral imager is particularly suited to detect and analyze objects having weak illumination.

Growing community of inventors

Alexandria, VA, United States of America

Paul A Bernhardt