Abstract: A system for monitoring a building having one or more microphones coupled to a telephone includes a detector configured to detect a triggering event within the building and transmit an activating signal when the triggering event is detected, and a control module configured to receive the activating signal from the detector. The control module is programmed to activate at least one of the one or more microphones to monitor sound when the activating signal is received.

Abstract: The period T.sub.nv of an oscillator signal is measured. A number N.sub.meas of cycles of the oscillator signal is determined based upon the measured oscillator period T.sub.nv and upon a desired minimum change in inductance .DELTA.L (sensitivity) which will result in an object being detected. The N.sub.meas cycles of the oscillator signal represent a measurement period. The length of the measurement period, defined by N.sub.meas oscillator cycles, is periodically determined. The length of the measurement period is compared to a reference value. An output, based upon the results of the comparison, is provided. Thereafter, the desired minimum change in inductance .DELTA.L (sensitivity) may be automatically adjusted by determining an average magnitude change in inductance .DELTA.L.sub.ave caused by a plurality of vehicles. The number N.sub.meas of oscillator cycles, which define the measurement period, is recalculated based upon the average magnitude change in inductance.

Abstract: An in flight damage assessment and surveillance system for aircraft using imaging apparatus for capturing optical images of predetermined portions of the aircraft disposed along the exterior of said aircraft in a manner such that the flight characteristics of the aircraft remain substantially unaltered. The images captured are recorded on a storage media mounted within the aircraft and having an enclosure which provides for the survival of the storage media even when subjected to the harsh environment of an aircraft crash. A display for displaying the captured optical images to aircraft crew members is also positioned within the aircraft along with apparatus for interfacing the imaging apparatus to recording apparatus and the display. The system can also include second imaging apparatus for capturing optical images of selected portions of the interior of the aircraft as well as a telemetry device for transmitting images to or from ground based stations.