Method and apparatus for determining soil strength from Doppler-shifted acoustic signatures
US5444670A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Sep 8, 1994 |
| Grant date | Aug 22, 1995 |
| Priority date | — |
| Expiry date | Sep 8, 2014 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N2291/02827
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A signal processing system for determining sea floor composition based on the frequency waveform and Doppler shift transmitted from an acoustic penetrometer includes a hydrophone for receiving the penetrometer waveform. The hydrophone output is digitized and passed to a general purpose computer where it is analyzed by a signal processing program. The signal processing program performs various signal transformations to increase the quality of the input waveform and isolates a penetration event. Additionally, the input signal is converted to an equivalent velocity waveform. A curve fitting algorithm is then used to determine the points within the velocity waveform that mark the initiation and termination of the penetration event that corresponds to the impact of the penetrometer with the sea floor. Once the initiation and termination of the penetration event are known, the velocity waveform is numerically integrated between those two points. The result of the numerical integration calculates the depth of penetration achieved during the penetration event. Based on the depth of penetration and other data, such as size and weight of the penetrometer, the composition of the sea floor at …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.