| 摘要 |
Frequency-steered acoustic arrays [30, 60, 120, etc.] transmitting and/or receiving multiple, angularly dispersed acoustic beams are used to generate 2D and 3D images. Input pulses to the arrays are generally non-linear, frequency-modulated pulses. Frequency-steered acoustic arrays may be provided in one-dimensional linear and two dimensional planar and curvilinear configurations, may be operated as single order or multiple order arrays, may employ periodic or non-periodic transducer element spacing, and may be mechanically scanned to generate 3D volumetric data. Multiple imaging fields of view may generated in different directions by switching the polarity of phase- shifted array transducer elements. Multiple frequency-steered arrays arranged in an X-configuration [150, 152, 164, 166] provide a wide, contiguous field of view and multiple frequency steered arrays arranged in a T-configuration [170, 172, 220] provide orthogonally oriented fields of view. Methods and systems for operating acoustic arrays in a frequency- steered mode in combination a mechanical beam steering mode, electronic time-delay and phase shift beam forming modes, and phase comparison angle estimation modes are also provided. |
