A radar signal sending method and a device provides for the sending of the radar signal to cooperative radars. A first time domain range in L time domain ranges is determined. A first radar signal is sent in the first time domain range. Any one of the L time domain ranges partially overlaps at least one of the other (L−1) time domain ranges, and an absolute value of a difference between time domain start locations of any two of the L time domain ranges is greater than or equal to a first threshold and less than or equal to a second threshold.

A radar signal sending method and a device provides for the sending of the radar signal to cooperative radars. A first time domain range in L time domain ranges is determined. A first radar signal is sent in the first time domain range. Any one of the L time domain ranges partially overlaps at least one of the other (L−1) time domain ranges, and an absolute value of a difference between time domain start locations of any two of the L time domain ranges is greater than or equal to a first threshold and less than or equal to a second threshold.

A sonar survey system and method excites reflectors using a broadband message that excites all frequencies within the band providing for selection and evaluation of frequencies of interest after the survey is completed.

A sonar survey system and method excites reflectors using a broadband message that excites all frequencies within the band providing for selection and evaluation of frequencies of interest after the survey is completed.

A method and device for processing an echo signal received from an acoustic sensor. The echo signal is detected over a measurement time interval. A minimum value is ascertained, which describes a minimum amplitude of the echo signal within the measurement interval. An amplitude value is ascertained, which describes an amplitude of the echo signal within a measurement window. The measurement window is a predefined time interval within the measurement interval. A difference is ascertained between the minimum value and the amplitude value. A determination is made whether the echo signal comprises an interference signal of the first type or an interference signal of the second type, based on the ascertained difference.

A method and device for processing an echo signal received from an acoustic sensor. The echo signal is detected over a measurement time interval. A minimum value is ascertained, which describes a minimum amplitude of the echo signal within the measurement interval. An amplitude value is ascertained, which describes an amplitude of the echo signal within a measurement window. The measurement window is a predefined time interval within the measurement interval. A difference is ascertained between the minimum value and the amplitude value. A determination is made whether the echo signal comprises an interference signal of the first type or an interference signal of the second type, based on the ascertained difference.

A moving object detection system comprises: a transmission waveform setting section to set a transmission signal in such a way that a frequency of the transmission signal is linearly changed; a transmitting section to transmit the transmission signal; a receiving section to receive a reception signal resulting from a reflection of the transmission signal at an object; a Doppler coefficient estimating section to estimate a Doppler coefficient associated with a movement of the object by performing arithmetic processing on a waveform of the reception signal at a present time point and waveforms of the reception signal at one or more past time points, the one or more past time points being earlier than the present time point by one or more specified periods of time; and an object detection section to detect the object based on the transmission signal, the Doppler coefficient, and the reception signal.

A moving object detection system comprises: a transmission waveform setting section to set a transmission signal in such a way that a frequency of the transmission signal is linearly changed; a transmitting section to transmit the transmission signal; a receiving section to receive a reception signal resulting from a reflection of the transmission signal at an object; a Doppler coefficient estimating section to estimate a Doppler coefficient associated with a movement of the object by performing arithmetic processing on a waveform of the reception signal at a present time point and waveforms of the reception signal at one or more past time points, the one or more past time points being earlier than the present time point by one or more specified periods of time; and an object detection section to detect the object based on the transmission signal, the Doppler coefficient, and the reception signal.

In one form, a method for acoustic distance measurement includes generating an acoustic signal with an acoustic transducer at a first time. A pulse is detected with the acoustic transducer in response to the acoustic signal encountering an obstacle within a predetermined distance. Detecting the pulse includes detecting a second time relative to the first time when a magnitude of the pulse rises above a predetermined threshold, and detecting a peak magnitude of the pulse. A correction ratio is determined as a ratio of the predetermined threshold to the peak magnitude of the pulse. A correction time is determined in response to the correction ratio. A corrected time-of-flight is determined by adjusting the second time by the compensation time.

In one form, a method for acoustic distance measurement includes generating an acoustic signal with an acoustic transducer at a first time. A pulse is detected with the acoustic transducer in response to the acoustic signal encountering an obstacle within a predetermined distance. Detecting the pulse includes detecting a second time relative to the first time when a magnitude of the pulse rises above a predetermined threshold, and detecting a peak magnitude of the pulse. A correction ratio is determined as a ratio of the predetermined threshold to the peak magnitude of the pulse. A correction time is determined in response to the correction ratio. A corrected time-of-flight is determined by adjusting the second time by the compensation time.