# US 2019/0170873 A1 · Systems and Methods for Acoustic and/or Electromagnetic Imaging > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2019/0170873 A1 - Document ID: US20190170873A1 - Status: Published application - Kind: A1 - Application number: 16/258,234 - Filed: 2019-01-25 - Published: 2019-06-06 - Earliest claimed: 2017-07-26 - Assignees: Sezanne Marine Limited - Applicants: Sezanne Marine Limited - Inventors: Ceri Reid - Web page: https://patentgrep.com/patent/US20190170873A1 ## CPC - G01S 15/102: {using transmission of pulses having some particular characteristics} - G01S 7/28: Details of pulse systems - G01S 7/282: Transmitters - G01S 7/292: Extracting wanted echo-signals - G01S 7/5202: {for pulse systems} - G01S 7/52025: {for pulse systems (G01S7/52034 takes precedence)} - G01S 7/52034: {Data rate converters} - G01S 7/523: Details of pulse systems {(short-range imaging G01S7/52017; methods or devices for transmitting, conducting or directing sound G10K11/18)} - G01S 7/526: Receivers - G01S 7/533: Data rate converters - G01S 13/006: {Theoretical aspects (G01S7/418, G01S13/9094, G01S13/958 take precedence)} - G01S 13/10: using transmission of interrupted, pulse modulated waves (determination of distance by phase measurement G01S13/32) - G01S 13/106: {using transmission of pulses having some particular characteristics (G01S13/12, G01S13/22, G01S13/24, G01S13/26, G01S13/28 and G01S13/30 take precedence)} - G01S 13/34: using transmission of continuous, frequency-modulated waves while heterodyning the received signal, or a signal derived therefrom, with a locally-generated signal related to the contemporaneously transmitted signal - G01S 13/89: for mapping or imaging - G01S 15/006: {Theoretical aspects} - G01S 15/10: using transmission of interrupted, pulse-modulated waves (determination of distance by phase measurement G01S15/32) - G01S 15/89: for mapping or imaging - G01S 15/8952: {using discrete, multiple frequencies} - G01S 15/8979: {Combined Doppler and pulse-echo imaging systems} - G01S: RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES ## Abstract A method for use in acoustic imaging, comprising: transmitting, from a transmitter, a first sound wave pulse at a first frequency determined by a maximum sampling rate of a receiver; transmitting at least one second sound wave pulse at a frequency substantially equal to the first frequency, the first and at least one second sound wave pulses being transmitted substantially within a fraction of a sample interval of the receiver; receiving and sampling, at the receiver, a reflection of at least two of the first and at least one second pulses to generate a set of receiver samples; and expanding the set of receiver samples, based on the first frequency and a total number of the first and at least one second pulses transmitted, to generate an expanded sample set with a larger number of samples than the set of receiver samples. ## Claims ### Claim 1 A method for use in imaging, comprising: transmitting, from a transmitter, a first wave pulse having a pulse length, at a first frequency determined by a maximum sampling rate of a receiver, which is a system operating frequency; transmitting at least one second wave pulse at a frequency substantially equal to the first frequency, the first and at least one second wave pulses being transmitted substantially within a time equal to the pulse length plus a fraction of a sample interval of the receiver; receiving and sampling, at the receiver, a reflection of at least two of: (i) the first and (ii) the at least one second wave pulses, to generate a set of receiver samples; and expanding the set of receiver samples, based on the first frequency and a total number of the first and at least one second wave pulses transmitted, to generate an expanded sample set. ### Claim 2 (depends on 1) The method of claim 1, further comprising: selecting a desired system angular resolution, determining a desired effective frequency of the expanded sample set based on that angular resolution, and performing pre-transmission bandpass sampling, wherein the first wave pulse is transmitted at a frequency ‘fo’, wherein fo is an operating frequency and is less than or equal to half the sampling rate ‘fs’, and wherein the set of samples from the first wave pulse is equivalent to a set of samples obtained from a wave pulse having an effective frequency equal to ‘fo+kfs’, wherein k is an integer. ### Claim 3 (depends on 1) The method of claim 1, further comprising undersampling each wave pulse, wherein each wave pulse is transmitted at least twice. ### Claim 4 (depends on 1) The method of claim 1, wherein expanding the set of receiver samples includes interleaving the receiver samples. ### Claim 5 (depends on 1) The method of claim 1, wherein the method is a method of performing demodulation of a wave, and wherein a first and a second wave pulse is transmitted, and wherein each respective reflection provides one of in-phase (I) data and quadrature or near-quadrature (Q) data, wherein the phase angle between the first and the second wave pulses is 2π/3 radians, with respect to a system operating frequency. ### Claim 6 (depends on 1) The method claim 1, wherein the method is a method of performing demodulation of a wave, and wherein a first, a second and a third wave pulse is transmitted, and wherein each respective reflection provides one of in-phase (I) data and quadrature or near-quadrature (Q) data, wherein the phase angle between the first and the second wave pulses is 2π/3 radians, with respect to a system operating frequency, and wherein the phase angle between the second and the third wave pulses is 2π/3 radians, with respect to the system operating frequency. ### Claim 7 (depends on 1) The method of claim 1, wherein at least one wave pulse is a multiplexed signal. ### Claim 8 (depends on 1) The method of claim 1, further comprising: obtaining phase information and magnitude information from at least one reflected wave pulse; using the sample interval, the phase information and the magnitude information to derive a frequency of the reflected wave pulse, and to derive a Doppler shift of the associated sample; and using the Doppler shift to derive the velocity of a target from which reflection occurred, relative to at least one of the transmitter and the receiver. ### Claim 9 (depends on 1) The method of claim 1, further including transmitting a duplicate of one of the first wave pulse or at least one second wave pulse. ### Claim 10 (depends on 1) A method according to claim 1, wherein the method is a method of performing demodulation of a wave, and wherein a first reflection provides an in-phase (I) sample and wherein a second reflection provides a quadrature or near-quadrature (Q) sample, wherein the second wave pulse is transmitted at a known phase angle from the first wave pulse. ### Claim 11 (depends on 10) The method of claim 10, wherein the known phase angle is a phase angle of π/2 radians, with respect to a system operating frequency. ### Claim 12 (depends on 1) The method of claim 1, wherein the method is a method of acoustic imaging, transmitting a first wave pulse comprises transmitting a first acoustic wave pulse, and transmitting a second wave pulse comprises transmitting a second acoustic wave pulse. ### Claim 13 (depends on 1) The method of claim 1, further including generating an image using the expanded sample set. ### Claim 14 A method for use in imaging comprising: creating a waveform having a waveform bandwidth; predicting samples obtainable by sampling the waveform at a sampling rate which is a multiple of the waveform bandwidth; defining, from the predicted samples, a first group of predicted samples and a second group of predicted samples; creating a first wave pulse for transmission based on the first group of predicted samples, having an operating frequency; creating a second wave pulse for transmission based on the second group of predicted samples; transmitting the first and second wave pulses, with an offset in transmission time based on the sample rate used to predict the samples; receiving and sampling respective reflections of the first and second wave pulses; and generating a received waveform sample set by interleaving the samples of the received first and second wave pulses. ### Claim 15 (depends on 14) A method according to claim 14, wherein the method is a method of performing demodulation of a wave, and wherein a first reflection provides an in-phase (I) sample and wherein a second reflection provides a quadrature or near-quadrature (Q) sample, wherein the second wave pulse is transmitted at a known phase angle from the first wave pulse. ### Claim 16 (depends on 15) The method of claim 15, wherein the known phase angle is a phase angle of π/2 radians, with respect to a system operating frequency. ### Claim 17 (depends on 14) The method of claim 14, wherein the method is a method of performing demodulation of a wave, and wherein a first and a second wave pulse is transmitted, and wherein each respective reflection provides one of in-phase (I) data and quadrature or near-quadrature (Q) data, wherein the phase angle between the first and the second wave pulses is 2π/3 radians, with respect to a system operating frequency. ### Claim 18 (depends on 14) The method claim 14, wherein the method is a method of performing demodulation of a wave, and wherein a first, a second and a third wave pulse is transmitted, and wherein each respective reflection provides one of in-phase (I) data and quadrature or near-quadrature (Q) data, wherein the phase angle between the first and the second wave pulses is 2π/3 radians, with respect to a system operating frequency, and wherein the phase angle between the second and the third wave pulses is 2π/3 radians, with respect to the system operating frequency. ### Claim 19 (depends on 14) The method of claim 14, wherein at least one wave pulse is a multiplexed signal. ### Claim 20 (depends on 14) The method of claim 14, further comprising: obtaining phase information and magnitude information from at least one reflected wave pulse; using the sample interval, the phase information and the magnitude information to derive a frequency of the reflected wave pulse, and to derive a Doppler shift of the associated sample; and using the Doppler shift to derive the velocity of a target from which reflection occurred, relative to at least one of the transmitter and the receiver. ### Claim 21 (depends on 14) The method of claim 14, further including transmitting a duplicate of one of the first wave pulse or at least one second wave pulse. ### Claim 22 (depends on 14) The method of claim 14, wherein the method is a method of acoustic imaging, transmitting a first and second wave pulses comprises transmitting first and second acoustic wave pulses. ### Claim 23 (depends on 14) The method of claim 14, further including generating an image using the received waveform sample set. ### Claim 24 A system for use in imaging, comprising: a transmitter configured to transmit a first wave pulse having a pulse length, at a first frequency determined by a maximum sampling rate of a receiver and configured to transmit at least one second wave pulse at a frequency substantially equal to the first frequency, the first and at least one second wave pulses being transmitted substantially within a time equal to the pulse length plus a fraction of a sample interval of the receiver; a receiver, configured to receive and sample a reflection of at least two of: (i) the first and (ii) the at least one second wave pulses to generate a set of receiver samples; and a processor operable to expand the set of receiver samples, based on the first frequency and a total number of the first and at least one second wave pulses transmitted, to generate an expanded sample set. ### Claim 25 (depends on 24) The system of claim 24, wherein the transmitter and receiver are arranged in an array, having an array spacing less than or equal to half the wavelength at the operating frequency. ### Claim 26 (depends on 24) The system according to claim 24, wherein the processor is operable to expand the set of receiver samples including ordering the receiver samples to correlate with the transmitted wave pulses. ### Claim 27 (depends on 24) The system according to claim 24, wherein the system is for acoustic imaging and the transmitter is configured to transmit acoustic wave pulses. ### Claim 28 (depends on 24) The system according to claim 24, wherein the processor is further configured to generate an image from the expanded sample set. ### Claim 29 A system for use in imaging, comprising: a transmitter, configured to transmit a first wave pulse and a second wave pulse, the first and second wave pulses created for transmission based on predicted samples obtainable by sampling a waveform having a waveform bandwidth, at a sampling rate which is a multiple of the waveform bandwidth and based on a first group of predicted samples and a second group of predicted samples defined from the predicted samples, the transmitter being further configured to transmit the first and second waves pulses with an offset in transmission time based on the sample rate used to predict the samples; a receiver configured to receive and sample respective reflections of the first and second wave pulses; and a processor configured to generate a received waveform sample set by interleaving the samples of the received first and second wave pulses. ### Claim 30 (depends on 29) The system of claim 29, wherein the transmitter and receiver are arranged in an array, having an array spacing less than or equal to half the wavelength at the operating frequency. ### Claim 31 (depends on 29) The system according to claim 29, wherein the processor is operable to expand the set of receiver samples including ordering the receiver samples to correlate with the transmitted wave pulses. ### Claim 32 (depends on 29) The system according to claim 29, wherein the system is for acoustic imaging and the transmitter is configured to transmit acoustic wave pulses. ### Claim 33 (depends on 29) The system according to claim 29, wherein the processor is further configured to generate an image from the received waveform sample set. ### Claim 34 A method for use in imaging, comprising: transmitting, from a transmitter, a first wave pulse having a pulse length, at a first frequency, which is a system operating frequency; transmitting at least one second wave pulse at a second frequency, the first and at least one second wave pulses being transmitted at least one of: (a) continuously, (b) with a negligible delay time between pulses, or (c) with a delay which is a fraction of a wavelength of the first or second wave pulse; receiving and sampling, at the receiver, a reflection of at least two of: (i) the first and (ii) the at least one second wave pulses, to generate a set of receiver samples; and expanding the set of receiver samples, based on the first and second frequencies and a total number of the first and at least one second wave pulses transmitted, to generate an expanded sample set. ### Claim 35 (depends on 34) The method according to claim 34, wherein the method is a method of performing demodulation of a wave, wherein the first wave pulse and the at least one second wave pulse have a known phase difference allowing the phase difference between the at least two received reflections to be determined. ### Claim 36 (depends on 34) The method according to claim 34, wherein the method is a method of performing demodulation of a wave, and wherein a first reflection provides an in-phase (I) sample and wherein a second reflection provides a quadrature or near-quadrature (Q) sample, wherein sampling uses a calculation of a phase angle between two samples to identify the in-phase sample and quadrature or near-quadrature sample. ### Claim 37 (depends on 34) The method according to claim 34, further including generating an image using the expanded sample set. ### Claim 38 (depends on 34) The method according to claim 34, further including determining the relative distances traversed by the first wave pulse and the at least one second wave, determining the distance to a target, wherein the target is the medium from which the first and at least one second wave pulses are reflected. ### Claim 39 (depends on 34) The method according to claim 34, further comprising undersampling each wave pulse, wherein each wave pulse is transmitted at least twice. ### Claim 40 A system for use in acoustic imaging, comprising: a transmitter configured to transmit a first wave pulse having a pulse length, at a first frequency and configured to transmit at least one second wave pulse at a second frequency, the first and at least one second wave pulses being transmitted at least one of: (a) continuously, (b) with a negligible delay time between pulses, or (c) with a delay which is a fraction of a wavelength of the first or second wave pulse; a receiver, configured to receive and sample a reflection of at least two of the first and at least one second wave pulses to generate a set of receiver samples; and a processor operable to expand the set of receiver samples, based on the first and second frequencies and a total number of the first and at least one second wave pulses transmitted, to generate an expanded sample set. ### Claim 41 (depends on 40) The system according to claim 40, wherein the processor is configured to perform demodulation of a wave, wherein the first wave pulse and the at least one second wave pulse have a known phase difference allowing the phase difference between the at least two received reflections to be determined. ### Claim 42 (depends on 40) The system according to claim 40, wherein the processor is configured to perform demodulation of a wave, and wherein a first reflection provides an in-phase (I) sample and wherein a second reflection provides a quadrature or near-quadrature (Q) sample, wherein processor is configured to calculate a phase angle between two samples to identify the in-phase sample and quadrature or near-quadrature sample. ### Claim 43 (depends on 40) The system according to claim 40, wherein the processor is further configured to generate an image from the expanded sample set. ### Claim 44 (depends on 40) The system according to claim 40, wherein the processor is further configured to determine the relative distances traversed by the first wave pulse and the at least one second wave pulse, determining the distance to a target, wherein the target is the medium from which the first and at least one second wave pulses are reflected.