Imaging systems

Claim 2

An imaging system comprising:- transducer means (10) movable along a given path and including emitter means (19) and receiver means (22) for emitting and receiving respectively in a direction generally transverse to said path; code generator means (14 to 18) operable to generate and supply to said emitter means a relatively narrow band emission signal comprising a plurality of coded waveforms each having a substantially delta-like auto-correlation function and a relatively low cross-correlation function; decoder means (18 to 34) for receiving the output signal of said receiver means and for decoding the output signal thereby to extract response data relating to each of said plurality of coded waveforms.

Claim 3

An imaging system according to claim 1, wherein said response data is stored and processed to provide data representative of a synthetic aperture image of the region swept by said transducer means.

Claim 4

An imaging system according to claim 1 or claim 2, wherein said transducer means emits and receives sound waves.

Claim 5

An imaging system according to any one of claims 1 to 3, wherein said decoder means (28 to 34) includes correlation means (39) for correlating the emission signal with the output signal of said receiver means thereby to extract and pulse-compress response data relating to each of said plurality of coded wave forms.

Claim 6

An imaging system according to any one of claims 1 to 4, wherein said decoder means (28 to 34) includes means (35) for adjusting the amplitude, weighting means for adjusting the phase weighting and means for adjusting the time delay of said response data thereby to effect focussing of the image sensed by said system.

Claim 7

An imaging system according to any one of claims 1 to 5, wherein said code generator means (14 to 18) includes store means (14) for storing in digital form data representative of the base band of the coded waveform digital to analog converter means (15) for converting said data, oscillator means (20) for generating a carrier frequency and mixer means (17) for mixing up the waveform from said converter means to said carrier frequency.

Claim 8

An imaging system according to any one of claims 1 to 5, wherein said code generation means (14 to 18) includes store means for storing data representative of the coded waveform and means for outputting data from said store thereby to generate said coded waveform.

Claim 9

A synthetic aperture sonar system comprising transducer means (10) movable along a given path and having emitter means (19) and receiver means (22) for emitting and receiving a sonar signal in a direction generally transverse to said given path, code generator means (14 to 18) for supplying to said emitter means (19) a plurality of coded waveforms, each having a substantially delta-like auto-correlation function, and a relatively low cross-correlation function and decoder means for decoding the output signal of the receiver means (28 to 34) thereby to extract response data relating to each of said plurality of coded waveforms.

Claim 10

A synthetic aperture sonar system comprising transducer means (10) movable along a given path and having emitter means (19) and receiver means (22) for emitting and receiving a sonar signal in a direction generally transverse to said given path, code generator means (14 to 18) for supplying to said emitter means (19) a plurality of coded waveforms, each having a substantially delta-like auto-correlation function, and a relatively low cross-correlation function and decoder means for decoding the output signal of the receiver means (28 to 34) thereby to extract response data relating to each of said plurality of coded waveforms.

Claim 11

A synthetic aperture sonar system according to claim 8, wherein said system includes a host vehicle (11) and a transducer vehicle (10) and means (12) for transmitting data between said vehicles, said transducer vehicle (10) housing said transducer means and said host vehicle housing said code generator means (14 to 18) and said decoder means (28 to 34).

Claim 12

A rapid coverage synthetic aperture sonar system comprising:- a host vehicle (11); a transducer vehicle (10); a towing link (12) connecting said host vehicle (11) and said transducer vehicle (10) and including data link means for transferring data between said host vehicle and said transducer vehicle; a memory (14) for storing data representing a plurality of coded waveforms each having a substantially delta-like autocorrelation function and a relatively low cross-correlation function; said transducer vehicle housing an emitter means (19) and a receiver means (22) for emitting and receiving sonar signals respectively, signal generator means (15 to 18) responsive to data in said memory for supplying to said emitter a plurality of coded waveforms, and analogue to digital conversion means (28) for digitising the output of the emitter means for transmission to the host link via said data link means, said host vehicle including pulse compression means (39) responsive to data representative of the coded waveforms to output data representing response data for each of said coded waveforms, store means (34) for storing the data output by said pulse compression means, and means (37) for processing and displaying the data contained in said store to provide an image of the area swept by said transducer vehicle.

Claim 13

A rapid coverage synthetic aperture sonar system comprising:- a host vehicle (11); a transducer vehicle (10); a towing link (12) connecting said host vehicle (11) and said transducer vehicle (10) and including data link means for transferring data between said host vehicle and said transducer vehicle; a memory (14) for storing data representing a plurality of coded waveforms each having a substantially delta-like autocorrelation function and a relatively low cross-correlation function; said transducer vehicle housing an emitter means (19) and a receiver means (22) for emitting and receiving sonar signals respectively, signal generator means (15 to 18) responsive to data in said memory for supplying to said emitter a plurality of coded waveforms, and analogue to digital conversion means (28) for digitising the output of the emitter means for transmission to the host link via said data link means, said host vehicle including pulse compression means (39) responsive to data representative of the coded waveforms to output data representing response data for each of said coded waveforms, store means (34) for storing the data output by said pulse compression means, and means (37) for processing and displaying the data contained in said store to provide an image of the area swept by said transducer vehicle.