As the size of the acoustic transducer is much larger than the wavelength of the acoustic wave, a circular scanning
system is adopted in order to implement the requirement of half wavelength spacing between the sensors.
The above reconstruction methods require enclosed detection for circular scanning
or an unbounded open surface for planar scanning, which are generally difficult to implement in a clinical situation.
Forming high-precision angular measuring structures by the laser pattern generators with circular scanning
, Measurement Science Review 6(1): 10-13.
These items were placed about 1-1/2 cm above the white circular scanning
head on a Plexiglas sheet.
A He-Ne laser beam focused down to spot, performs circular scanning
by a rotating wedge prism of the sample measurement volume.