The Boeing Company

David J Morris

Diane C Rawlings

David F King

Victor T Webbeking

Method and apparatus for measuring thermal radiation emitted by a sample, and for determining emissivity. The apparatus comprises a chamber in which the sample may be positioned, the chamber comprising a plurality of walls including a first wall containing an observation port. The chamber is located in a cold environment, and the walls of the chamber are brought to a selected temperature by circulating a temperature conditioned fluid through the walls. The sample is moved along a movement axis within the chamber past the observation port. As the sample is so moved, radiation emitted outwards through the observation port by the sample is measured.

Emissivity measurement apparatus and method

Apparatus and method for determining velocity and range of a target within a field of view. A velocimeter and tracker (10, 100) includes a laser (12, 12') that produces modulated coherent light, a portion of which illuminates targets (22, 22') coming into a field of view (24, 24') of the velocimeter and tracker. Coherent light reflected from the target travels back along a detection path toward a phase conjugate mirror (40, 40') as a probe wave (26, 26'). A higher intensity portion of the coherent light produced by the laser is split into equal parts that are directed toward the phase conjugate mirror from opposite directions and interact with the probe wave to produce a phase conjugate light signal that travels back along the detection path and is also reflected from the target. Light reflected by the target experiences a Doppler phase shift as a function of target velocity. First, second, and higher order phase shifted signals reflected from the target are imaged on photo diodes (68, 68'), producing an electrical signal having components corresponding to the frequency differences of the various order light signals. As a function of the sums and differences of the frequency components of the electrical signal, the range and velocity of the target are determined.

Optical phase conjugate velocimeter and tracker

Four-wave mixing is used to produce a steered optical phase conjugate wave. First and second pump waves are combined with a probe wave in a nonlinear medium within an optical conjugate, producing an optical phase conjugate wave. The magnitude of the wave vectors corresponding to the first and second pump waves are different, causing the optical phase conjugate wave to define a non-zero angle .theta..sub.0 relative to the probe wave. In a first embodiment, the wavelengths of the first and second pump waves are controlled to vary the angle, while in a second embodiment, the intensities of the two pump waves are modified.

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Kent, WA, United States of America

David J Morris