초록 ▼

A beam of electromagnetic radiation is spatially encoded using a digital frequency diversity technique. The spatial encoding defines the beam cross-section into a series of resolution elements each identified by a different digital code. The codes defining resolution elements are detectable by an ob

A beam of electromagnetic radiation is spatially encoded using a digital frequency diversity technique. The spatial encoding defines the beam cross-section into a series of resolution elements each identified by a different digital code. The codes defining resolution elements are detectable by an object, such as a missile, located in the radiation beam and can be used to locate the object in this beam. In the preferred embodiment, an encoding mask, moved through the beam, provides the digital frequency modulation. The mask is provided with a series of bit areas, each of which bears at least two sets of cyclically recurring bands effective to modulate a detectable parameter of the radiation, such as intensity. The spacing between adjacent bands of a set, termed a bit cycle, is proportional to a predetermined frequency of beam parameter modulation. The novel arrangement enables the object to identify its position within the beam under conditions of severe atmospheric turbulence and object induced perturbations.

대표청구항 ▼

An encoding mask for use in conjunction with an electromagnetic beam of radiation for spatially encoding the beam as the mask is moved through the beam at a constant, predetermined speed to thereby facilitate the locating of an object in space, comprising: a surface having a series of adjacent regio

An encoding mask for use in conjunction with an electromagnetic beam of radiation for spatially encoding the beam as the mask is moved through the beam at a constant, predetermined speed to thereby facilitate the locating of an object in space, comprising: a surface having a series of adjacent regions defining bit areas, each of said regions being defined by at least two sets of spaced apart cyclically recurring bands effective to vary a detectable beam parameter, the spacing between adjacent bands of a set being preselected to produce a predetermined beam modulation frequency as the surface is moved through the beam, the spacing between adjacent bands of one set of bands within a bit area being different from the spacing between adjacent bands of at least one other set of bands within the same bit area to thereby spatially modulate the beam at two frequencies, at least, as a bit area is moved through the beam.