Method of high resolution and high SNR data acquisition for probing using pulse-compression

US5426618A · kind A · utility

Inventors

• Hong Chen · Zhejiang, CN
• Neng E. Wu · Town of DeWitt, US

Key dates

• Filing date: May 3, 1993
• Grant date: Jun 20, 1995
• Expiry date: May 3, 2013

Classification

• Technology area (CPC G): Physics
• CPC primary: G01S15/104
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

Excellent likeness of impulse response function r.sub.o (t) of a given linear space is obtained by exciting the space through a transmitting transducer with a compressible probing signal x(t) which is a string of lowpass narrow p(t)-wavelets polarity-controlled by a single cycle of an m-sequence and processing received raw-data by cross-correlating it with a special reference s(t) which is cyclical repetition of the same m-sequence. Cross-correlating x(t) directly with s(t) yields compressed version of x(t) (denoted e(t)) which is p(t) multiplied by length of the m-sequence. e(t) equivalently excites the space to give processed output which is the likeness of r.sub.o (t). e(t) is free from side-lobes and readily made arbitrarily slim by choosing p(t) slim; keeping duration and energy of x(t) fixed, e(t) characterizes an area invariant of the slimness of e(t) or p(t). Above qualities of e(t) eliminate causes of inability to achieve high resolution and high SNR and need for increased excitation and increased power rating of transmitting transducer of conventional method which uses signal CHIRP. Cross-correlated with s(t), colored noise is minimized. Choosing width of p(t) narrower th…