Pulse radar method and apparatus for detecting an object

Claim 1

A method for detecting an object by a pulse radar method, comprising: receiving as an observation signal an electromagnetic wave which is an echo wave returned back from an object; dividing said observation signal into separate divided signal portions for a predetermined time interval; transforming each divided signal portion into a frequency region by Fast Fourier Transformation to find a spectral distribution; reading from the spectral distribution at least two of the following parameter values, a spectral peak frequency value f p , a DC component ratio value R dc and a half value width value W as one combination; extracting only each wave returned back from an object being detected, by eliminating as a spurious echo wave from said spectral distribution parameter values divided signal portions having a value other than that of the spectral peak frequency f p falling within a predetermined frequency range, that of the DC component ratio R dc falling within a predetermined DC component ratio, or that of the half value width W falling within a predetermined half value width; and displaying a cross-sectional image of the object from said extracted respective wave.

Claim 2

A method for detecting an object by a pulse radar method, comprising: receiving as an observation signal an electromagnetic wave which is an echo wave returned back from an object; dividing said observation signal into separate divided signal portions for a predetermined time interval; transforming each divided signal portion into a frequency region by Fast Fourier Transformation to find a spectral distribution; reading from the spectral distribution at least two of the following parameter values, a spectral peak frequency value f p , a DC component ratio value R dc and a half value width value W as one combination; extracting only each wave returned back from an object being detected, by eliminating as a spurious echo wave from said spectral distribution parameter values divided signal portions having a value other than that of the spectral peak frequency f p falling within a predetermined frequency range, that of the DC component ratio R dc falling within a predetermined DC component ratio, or that of the half value width W falling within a predetermined half value width; and displaying a cross-sectional image of the object from said extracted respective wave.

Claim 6

An apparatus for detecting an object, comprising: transmitting/receiving means for transmitting an electromagnetic wave and receiving as an observation signal an echo wave which is the electromagnetic wave returned back from the object; sampling means for sampling said observation signal; a signal dividing means for, after converting the signal which has been sampled into a digital signal through an A/D conversion, dividing the observation signal into separate divided signal waveform portions for a predetermined time interval ΔT; means for transforming each divided signal portion into a frequency region by Fast Fourier Transformation to find a spectral distribution; means for reading from each spectral distribution corresponding to the respective divided observation signal at least two of the following parameter values, a spectrum peak frequency value f p , a DC component ratio R dc and a half value width value W as one combination, for eliminating as a spurious echo wave from all parameter values divided signal portions having a value other than that of said spectral peak frequency f p falling within a predetermined frequency range, that of said DC component ratio R dc falling within a predetermined DC component range or that of said half value width W falling within a predetermined half value width, and extracting only an echo wave which is returned back from said object of linear structure; and display means for displaying the object as a reconstituted cross-sectional image corresponding to the object.

Claim 7

An apparatus for detecting an object, comprising: transmitting/receiving means for transmitting an electromagnetic wave and receiving as an observation signal an echo wave which is the electromagnetic wave returned back from the object; sampling means for sampling said observation signal; a signal dividing means for, after converting the signal which has been sampled into a digital signal through an A/D conversion, dividing the observation signal into separate divided signal waveform portions for a predetermined time interval ΔT; means for transforming each divided signal portion into a frequency region by Fast Fourier Transformation to find a spectral distribution; means for reading from each spectral distribution corresponding to the respective divided observation signal at least two of the following parameter values, a spectrum peak frequency value f p , a DC component ratio R dc and a half value width value W as one combination, for eliminating as a spurious echo wave from all parameter values divided signal portions having a value other than that of said spectral peak frequency f p falling within a predetermined frequency range, that of said DC component ratio R dc falling within a predetermined DC component range or that of said half value width W falling within a predetermined half value width, and extracting only an echo wave which is returned back from said object of linear structure; and display means for displaying the object as a reconstituted cross-sectional image corresponding to the object.

Claim 8

A method for detecting an object, comprising the steps of: receiving a plurality of observation signals including cross-sectional data relating to a direction substantially perpendicular to that of a buried object having a linear structure so as to recognize the buried object; dividing each of said plurality of observation signals, constituting a plurality of cross-sectional data, into separate divided signal portions for a predetermined time interval ΔT; transforming each divided signal portion into a corresponding frequency region by Fast Fourier Transformation to find a spectral distribution; reading from the respective spectral distribution corresponding to each of said plurality of divided signal portions at least two of the following parameter values, a spectral peak frequency value f p , a DC component ratio value R dc and a half value width value W as one combination; extracting only echo wave returned back from the object by eliminating as a spurious echo wave from the parameter values of the spectral distribution a value other than that of said spectral peak frequency f p falling within a predetermined frequency range, that of the DC component ratio R dc falling within a predetermined DC component ratio R dc and that of said fall value width W falling within a predetermined range; performing a correlation computation on multi-cross-section data corresponding to the extracted echo wave returned back from the object and extracting only an echo wave returned back from the object of a linear structure; and displaying a result of the correlation computation as a cross-sectional image of the object of a linear structure.

Claim 9

A method for detecting an object, comprising the steps of: receiving a plurality of observation signals including cross-sectional data relating to a direction substantially perpendicular to that of a buried object having a linear structure so as to recognize the buried object; dividing each of said plurality of observation signals, constituting a plurality of cross-sectional data, into separate divided signal portions for a predetermined time interval ΔT; transforming each divided signal portion into a corresponding frequency region by Fast Fourier Transformation to find a spectral distribution; reading from the respective spectral distribution corresponding to each of said plurality of divided signal portions at least two of the following parameter values, a spectral peak frequency value f p , a DC component ratio value R dc and a half value width value W as one combination; extracting only echo wave returned back from the object by eliminating as a spurious echo wave from the parameter values of the spectral distribution a value other than that of said spectral peak frequency f p falling within a predetermined frequency range, that of the DC component ratio R dc falling within a predetermined DC component ratio R dc and that of said fall value width W falling within a predetermined range; performing a correlation computation on multi-cross-section data corresponding to the extracted echo wave returned back from the object and extracting only an echo wave returned back from the object of a linear structure; and displaying a result of the correlation computation as a cross-sectional image of the object of a linear structure.

Claim 13

An apparatus for detecting an object, comprising: means for receiving a plurality of observation signals including cross-sectional data relating to a direction substantially perpendicular to that of a buried object having a linear structure so as to recognize the buried object; means for sampling said plurality of observation signals constituting a plurality of cross-sectional data; signal dividing means for after converting a signal which is sampled by said sampling means into a digital signal through an A/D conversion process, dividing the observation signal into separate divided signal portions for a predetermined time interval ΔT; means for transforming each divided signal portion into a frequency region by Fast Fourier Transformation to find a spectral distribution; means for reading from each spectral distribution corresponding to the respective divided observation signal at least two of the following parameter values, a spectrum peak frequency value f p , a DC component ratio R dc and a half value width value W as one combination, for eliminating as a spurious echo wave from all parameter values divided signal portions having a value other than that of said spectral peak frequency f p falling within a predetermined frequency range, that of said DC component ratio R dc falling within a predetermined DC component range or that of said half value width W falling within a predetermined half value width, and extracting only an echo wave which is returned back from said object of linear structure; means for performing a correlation computation on said multi-cross-section data corresponding to the extracted echo wave and for extracting only an echo wave which is returned back from said object of a linear structure; and display means for displaying a result of the correlation computation as a cross-sectional image corresponding to said object of a linear structure.

Claim 14

An apparatus for detecting an object, comprising: means for receiving a plurality of observation signals including cross-sectional data relating to a direction substantially perpendicular to that of a buried object having a linear structure so as to recognize the buried object; means for sampling said plurality of observation signals constituting a plurality of cross-sectional data; signal dividing means for after converting a signal which is sampled by said sampling means into a digital signal through an A/D conversion process, dividing the observation signal into separate divided signal portions for a predetermined time interval ΔT; means for transforming each divided signal portion into a frequency region by Fast Fourier Transformation to find a spectral distribution; means for reading from each spectral distribution corresponding to the respective divided observation signal at least two of the following parameter values, a spectrum peak frequency value f p , a DC component ratio R dc and a half value width value W as one combination, for eliminating as a spurious echo wave from all parameter values divided signal portions having a value other than that of said spectral peak frequency f p falling within a predetermined frequency range, that of said DC component ratio R dc falling within a predetermined DC component range or that of said half value width W falling within a predetermined half value width, and extracting only an echo wave which is returned back from said object of linear structure; means for performing a correlation computation on said multi-cross-section data corresponding to the extracted echo wave and for extracting only an echo wave which is returned back from said object of a linear structure; and display means for displaying a result of the correlation computation as a cross-sectional image corresponding to said object of a linear structure.

Claim 15

A method for detecting an object, comprising the steps of: receiving as an observation signal an electromagnetic wave which is an echo wave returned back from an object; dividing said observation signal into separate divided signal portions for a predetermined time interval ΔT; transforming each divided signal portion into a frequency region by Fast Fourier Transformation to find a spectral distribution; reading from said spectral distribution at least two of the following spectral distribution parameter values, a spectral peak frequency value f p , a DC component ratio value R dc and a half value width value W as one combination; extracting only an echo wave from said object by eliminating as a spurious echo wave divided signal portions having a value other than that of said spectrum peak frequency f p falling within a predetermined DC component ratio R dc falling within a predetermined DC component ratio range, or that of said half value width W falling within a predetermined half value width range; performing a synthetic-aperture processing by computing a hyperbolic configuration having an arbitrary position (X 1 , Z 1 ) as an apex in the earth cross-section corresponding to the echo wave by said step for extracting only an echo wave from said object where i=1˜n, j=1˜m and an, m: data points, adding to an amplitude of the apex (X 1 , Z 1 ) the amplitude of a waveform on said hyperbolic configuration calculated and recognizing, as a buried position of said object, that coordinate position (X 1 , Z 1 ) which is peaked in amplitude by doing so at said step; and displaying a synthetic-aperture-processed echo wave as a cross-sectional image whose horizontal resolution is improved.

Claim 16

A method for detecting an object, comprising the steps of: receiving as an observation signal an electromagnetic wave which is an echo wave returned back from an object; dividing said observation signal into separate divided signal portions for a predetermined time interval ΔT; transforming each divided signal portion into a frequency region by Fast Fourier Transformation to find a spectral distribution; reading from said spectral distribution at least two of the following spectral distribution parameter values, a spectral peak frequency value f p , a DC component ratio value R dc and a half value width value W as one combination; extracting only an echo wave from said object by eliminating as a spurious echo wave divided signal portions having a value other than that of said spectrum peak frequency f p falling within a predetermined DC component ratio R dc falling within a predetermined DC component ratio range, or that of said half value width W falling within a predetermined half value width range; performing a synthetic-aperture processing by computing a hyperbolic configuration having an arbitrary position (X 1 , Z 1 ) as an apex in the earth cross-section corresponding to the echo wave by said step for extracting only an echo wave from said object where i=1˜n, j=1˜m and an, m: data points, adding to an amplitude of the apex (X 1 , Z 1 ) the amplitude of a waveform on said hyperbolic configuration calculated and recognizing, as a buried position of said object, that coordinate position (X 1 , Z 1 ) which is peaked in amplitude by doing so at said step; and displaying a synthetic-aperture-processed echo wave as a cross-sectional image whose horizontal resolution is improved.

Claim 17

An apparatus for detecting an object, comprising: transmitting/receiving means for transmitting an electromagnetic wave and receiving as an observation signal a corresponding echo wave returned back from the object; sampling means for sampling said observation signal; dividing means for after converting a signal which is sampled by said sampling means into a digital signal through an A/D conversion, dividing the observation signal into separate divided signal portions for a predetermined time; means for transforming each divided signal portion into a frequency region by Fast Fourier Transformation to find a spectral distribution; and means for reading from said spectral distribution at least two of the following parameter values, a spectrum peak frequency value f p , a DC component ratio R dc and a half value width value W as one combination; means for extracting only an echo wave from said object by eliminating as a spurious echo wave from said parameter values divided signal portions having a value other than that of said spectral frequency f p falling within a predetermined frequency range, that of said DC component ratio R dc falling within a predetermined DC component range or that of said half value width W falling within a predetermined half value width range; a synthetic-aperture processing means for computing a hyperbolic configuration having an arbitrary position (X 1 , Z 1 ) as an apex in the earth cross-section corresponding to the echo wave by said step for extracting only an echo wave from said object where i=1˜n, j=1˜m and n, m: data points, adding to an amplitude of the apex (X 1 , Z 1 ) the amplitude of a waveform on said hyperbolic configuration calculated and recognizing, as a buried position of said object, that coordinate position (X 1 , Z z ) which is peaked in amplitude by doing so; and means for displaying the synthetic-aperture-processed echo wave as a cross-sectional image whose horizontal resolution is enhanced.

Claim 18

An apparatus for detecting an object, comprising: transmitting/receiving means for transmitting an electromagnetic wave and receiving as an observation signal a corresponding echo wave returned back from the object; sampling means for sampling said observation signal; dividing means for after converting a signal which is sampled by said sampling means into a digital signal through an A/D conversion, dividing the observation signal into separate divided signal portions for a predetermined time; means for transforming each divided signal portion into a frequency region by Fast Fourier Transformation to find a spectral distribution; and means for reading from said spectral distribution at least two of the following parameter values, a spectrum peak frequency value f p , a DC component ratio R dc and a half value width value W as one combination; means for extracting only an echo wave from said object by eliminating as a spurious echo wave from said parameter values divided signal portions having a value other than that of said spectral frequency f p falling within a predetermined frequency range, that of said DC component ratio R dc falling within a predetermined DC component range or that of said half value width W falling within a predetermined half value width range; a synthetic-aperture processing means for computing a hyperbolic configuration having an arbitrary position (X 1 , Z 1 ) as an apex in the earth cross-section corresponding to the echo wave by said step for extracting only an echo wave from said object where i=1˜n, j=1˜m and n, m: data points, adding to an amplitude of the apex (X 1 , Z 1 ) the amplitude of a waveform on said hyperbolic configuration calculated and recognizing, as a buried position of said object, that coordinate position (X 1 , Z z ) which is peaked in amplitude by doing so; and means for displaying the synthetic-aperture-processed echo wave as a cross-sectional image whose horizontal resolution is enhanced.

Claim 19

A method for detecting an object, comprising the steps of: receiving a plurality of observation signals including cross-sectional data relating to a direction substantially perpendicular to that of a buried object having a linear structure so as to recognize the buried object; dividing respective observation signals, constituting said cross-sectional data, into separate divided signal portions for a predetermined time interval ΔT; transforming each divided signal portion into a frequency region by Fast Fourier Transformation to find a spectral distribution; reading, from the spectrum distribution corresponding to the respective divided signal portion, at least two of the following parameter values, a spectrum peak frequency value F p , a DC component ratio value R dc and a half value width value W as one combination; extracting only each wave from said object by eliminating as a spurious echo wave from the respective spectrum distribution parameter values divided signal portion having a value other than that of said spectrum peak frequency f p falling within a predetermined frequency range, that of said DC component ratio R dc falling within a predetermined DC component ratio range and that of said half width value W; performing a correlation computation on multi-cross-section data corresponding to said extracted echo wave returned back from an object and extracting only an echo wave returned back from an object of a linear structure; and performing a synthetic-aperture processing by computing a hyperbolic configuration having an arbitrary position (X 1 , Z 1 ) as an apex in the earth cross-section corresponding to the echo wave by said step for extracting only an echo wave from said object where i=1˜n, j=1˜m and n, m: data points, adding to an amplitude of the apex (X 1 , Z 1 ) the amplitude of a waveform on said hyperbolic configuration calculated and recognizing, as a buried position of said object, that coordinate position (X 1 , Z 1 ) which is peaked in amplitude by doing so at said step; and displaying the echo wave, which is subjected to the correlation computation and synthetic-aperture processing, as a cross-sectional image of said object of a linear structure whose horizontal resolution is enhanced.

Claim 20

A method for detecting an object, comprising the steps of: receiving a plurality of observation signals including cross-sectional data relating to a direction substantially perpendicular to that of a buried object having a linear structure so as to recognize the buried object; dividing respective observation signals, constituting said cross-sectional data, into separate divided signal portions for a predetermined time interval ΔT; transforming each divided signal portion into a frequency region by Fast Fourier Transformation to find a spectral distribution; reading, from the spectrum distribution corresponding to the respective divided signal portion, at least two of the following parameter values, a spectrum peak frequency value F p , a DC component ratio value R dc and a half value width value W as one combination; extracting only each wave from said object by eliminating as a spurious echo wave from the respective spectrum distribution parameter values divided signal portion having a value other than that of said spectrum peak frequency f p falling within a predetermined frequency range, that of said DC component ratio R dc falling within a predetermined DC component ratio range and that of said half width value W; performing a correlation computation on multi-cross-section data corresponding to said extracted echo wave returned back from an object and extracting only an echo wave returned back from an object of a linear structure; and performing a synthetic-aperture processing by computing a hyperbolic configuration having an arbitrary position (X 1 , Z 1 ) as an apex in the earth cross-section corresponding to the echo wave by said step for extracting only an echo wave from said object where i=1˜n, j=1˜m and n, m: data points, adding to an amplitude of the apex (X 1 , Z 1 ) the amplitude of a waveform on said hyperbolic configuration calculated and recognizing, as a buried position of said object, that coordinate position (X 1 , Z 1 ) which is peaked in amplitude by doing so at said step; and displaying the echo wave, which is subjected to the correlation computation and synthetic-aperture processing, as a cross-sectional image of said object of a linear structure whose horizontal resolution is enhanced.

Claim 24

An apparatus for detecting an object, comprising: receiving means for receiving a plurality of observation signals including cross-sectional data relating to a direction substantially perpendicular to that of a buried object having a linear structure so as to recognize the buried object; sampling means for sampling said plurality of observation signals constituting a plurality of cross-sectional data; signal dividing means for after converting a respective signal which is sampled by said sampling means into a digital signal through an A/D conversion, dividing the sampled observation signal into separate divided signal portions for a predetermined time interval ΔT; means for transforming each divided signal portion by a Fast Fourier Transformer means for finding a spectral distribution into a frequency region; means for reading at least two of the following parameter values, a spectrum peak frequency value F p , a DC component ratio value R dc and a half value width value W as one combination and extracting only an echo wave returned back from said object by eliminating as a spurious signal a divided signal portion having a value other than that of said spectral peak frequency value f p falling within a predetermined frequency range, that of said DC component ratio value R dc falling within a predetermined DC component ratio or that of said half value width value W falling within a predetermined half value width; means for performing a correlation computation on said multi-cross-section data corresponding to the extracted echo wave and for extracting only an echo wave from said object of a linear structure; synthetic-aperture processing means including means for evaluating a hyperbolic configuration with predetermined points as an apex below the surface of the earth area corresponding to the echo wave returned back from said object of a linear structure and means for additively combining a waveform amplitude on the hyperbola with the amplitude of the respective apex; and means for displaying said echo wave, which is subjected to said correlation computation and synthetic-aperture processing, as a cross-sectional image of said object of a linear structure whose horizontal resolution is enhanced.

Claim 25

An apparatus for detecting an object, comprising: receiving means for receiving a plurality of observation signals including cross-sectional data relating to a direction substantially perpendicular to that of a buried object having a linear structure so as to recognize the buried object; sampling means for sampling said plurality of observation signals constituting a plurality of cross-sectional data; signal dividing means for after converting a respective signal which is sampled by said sampling means into a digital signal through an A/D conversion, dividing the sampled observation signal into separate divided signal portions for a predetermined time interval ΔT; means for transforming each divided signal portion by a Fast Fourier Transformer means for finding a spectral distribution into a frequency region; means for reading at least two of the following parameter values, a spectrum peak frequency value F p , a DC component ratio value R dc and a half value width value W as one combination and extracting only an echo wave returned back from said object by eliminating as a spurious signal a divided signal portion having a value other than that of said spectral peak frequency value f p falling within a predetermined frequency range, that of said DC component ratio value R dc falling within a predetermined DC component ratio or that of said half value width value W falling within a predetermined half value width; means for performing a correlation computation on said multi-cross-section data corresponding to the extracted echo wave and for extracting only an echo wave from said object of a linear structure; synthetic-aperture processing means including means for evaluating a hyperbolic configuration with predetermined points as an apex below the surface of the earth area corresponding to the echo wave returned back from said object of a linear structure and means for additively combining a waveform amplitude on the hyperbola with the amplitude of the respective apex; and means for displaying said echo wave, which is subjected to said correlation computation and synthetic-aperture processing, as a cross-sectional image of said object of a linear structure whose horizontal resolution is enhanced.