Abstract: Method and apparatus for using a guided wave to determine the location of one or more flaws in an inspected object are disclosed. An ultrasonic guided wave is launched into the object using conventional ultrasound methods, and the reflected/received guided wave is sampled to capture a series of individual reflected waveforms. The individual reflected waveforms are then partitioned according to the sampling time. Each of the partitioned acquired waveforms is compared with a selected time-varying dispersion-modeled reference waveform associated with the unique geometry of the inspected object, a multiplicity of “theoretical” flaw locations, and the characteristics of the original ultrasonic guided wave. To make a comparison, the reference waveform is also generated as a series of partitioned waveforms which model the shape of a wave that may be expected to be reflected from a multiplicity of theoretical flaws located in the object.

Abstract: A constrained-envelope digital communications transmitter (10) places constraints on the envelope of spectrally constrained, digitally modulated communication signals (46) converted into diverse frequency channels (54) and combined into a composite signal (58). The envelope constraints achieve lower peak-to-average power ratio without allowing significant spectral regrowth. The composite signal (58) is applied to a plurality of cascade-coupled constrained-envelope generators (64). Each constrained-envelope generator (64) detects overpeak events (66) and configures corrective impulses (68) for the overpeak events (66). The corrective impulses (68) are distributed to the respective frequency channels (54) in accordance with a predetermined distribution profile (102) and are filtered into allocated shaped pulses (120) that exhibit a constrained spectrum.

Abstract: Method and apparatus for using a guided wave to determine the location of one or more flaws in an inspected object are disclosed. An ultrasonic guided wave is launched into the object using conventional ultrasound methods, and the reflected/received guided wave is sampled to capture a series of individual reflected waveforms. The individual reflected waveforms are then partitioned according to the sampling time. Each of the partitioned acquired waveforms is compared with a selected time-varying dispersion-modeled reference waveform associated with the unique geometry of the inspected object, a multiplicity of “theoretical” flaw locations, and the characteristics of the original ultrasonic guided wave. To make a comparison, the reference waveform is also generated as a series of partitioned waveforms which model the shape of a wave that may be expected to be reflected from a multiplicity of theoretical flaws located in the object.