Seismic aircraft maneuver classifier
US4322828A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 9, 1981 |
| Grant date | Mar 30, 1982 |
| Priority date | — |
| Expiry date | Jan 9, 2001 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01V1/001
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
Apparatus for classifying the activity of an aircraft including the geophone proximate an airfield used by jet airplanes for generating a signal indicative of the existence of the jet aircraft. Amplifier means are provided for enhancing the signal. The signal is then passed through a low pass filter means for receiving the signal and passing only that portion having a frequency less than about 30 Hz. A high band pass filter also receives the signal and passes only that portion having a frequency ranging from about 90 Hz to about 120 Hz. Two demodulator means are provided which receive the low pass signal to provide a low pass envelope and receive the high band pass signal to produce a high band pass envelope. Threshold signal generating means are provided to receive the low pass envelope and the high band pass envelope, and generate a signal when either or both envelopes reach a predetermined threshold. Finally, comparator means are provided for comparing the time sequence of the signals generated by said threshold signal generating means to determine the activity of the jet aircraft. In a preferred embodiment, a means for indicating the existence of a taxing aircraft is provided w…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.