Method and apparatus for improving the performance of an aperture monitoring system

A system for monitoring a space within or proximate to an aperture, said system comprising:

• an emitter for emitting radiation adjacent said aperture;
• a surface adjacent said aperture for reflecting a portion of said emitted radiation;
• a material applied to said surface for altering an intensity of said reflected radiation;
• a receiver adapted to receive at least a portion of said reflected radiation;
• and
• a processing element for determining if an intensity of said reflected radiation received by said receiver equals or exceeds a threshold level,
• wherein said material improves a signal-to-noise ratio of said receiver as compared to a monitoring system not comprising said material.

A system for monitoring a space within or proximate to an aperture, said system comprising:

• an emitter for emitting radiation adjacent said aperture;
• a receiver adapted to receive said radiation as reflected from said space and to generate an output signal based upon said received radiation;
• a reference source for providing a reference signal to said receiver;
• and
• a processing element for comparing said output signal to a threshold value.

A method of monitoring a space adjacent to or within an aperture comprising the steps of:

• generating first reference radiation by applying a first reference drive signal to a reference emitter;
• receiving said reference radiation by a receiver;
• generating a first receiver output signal based upon said received reference radiation;
• adjusting said first reference drive signal until a desired value for said output signal is generated by said receiver;
• generating measurement radiation by applying a first measurement drive signal, based upon said first reference drive signal, to a measurement emitter;
• receiving reflected measurement radiation by said receiver;
• and
• generating a second receiver output signal based upon said received, reflected, measurement radiation.

A system for monitoring a space adjacent to or within an aperture, comprising:

• an emitter for emitting radiation adjacent said aperture;
• a receiver adapted to receive said radiation as reflected from said space;
• a processing element for determining if an intensity of said reflected radiation received by said receiver equals or exceeds a threshold level;
• and
• a calibrating element for calibrating said system based upon said intensity of said reflected radiation.

A method of calibrating a system for monitoring a space adjacent to or within an aperture, said system comprising an emitter for emitting a radiation field adjacent said aperture, a receiver for receiving at least a reflected portion of said radiation field and for generating an output signal indicative of an intensity of said reflected radiation field, and a processing element for comparing said output signal with a threshold value, said method comprising the steps of:

• providing a calibration signal to said processing element;
• emitting said radiation field by said emitter;
• receiving said reflected portion of said radiation field by said receiver and generating said output signal;
• and
• adjusting, by said processing element, characteristics of said emitter and/or said receiver in response to said output signal.

A system for monitoring a space within or proximate to an aperture, comprising:

• an emitter for emitting radiation adjacent said aperture;
• a receiver for receiving said radiation as reflected from said space and for generating an output signal based upon said received radiation;
• and
• a processing element for calculating a difference between said output signal and a first threshold value and for controlling one or both of said emitter and said receiver based upon said calculated difference.

A method of monitoring a spatial volume proximate an aperture, said method comprising the steps of:

• emitting radiation adjacent said aperture;
• receiving a portion of said radiation reflected from a surface in said aperture environment;
• generating an output signal based upon said received radiation;
• calculating a difference between said output signal and a first threshold value;
• and
• controlling one or both of said emitting and said generating steps based upon said calculated difference to effect said calculated difference.