How small is the spatial resolution?
In ultrasonic Doppler velocimetry, the shape and lateral sizes of the sampling volumes (measured perpendicularly to the ultrasonic beam axis) are defined by the geometry of the ultrasonic beam. The longitudinal size of the sampling volumes is defined by the burst length and/or the bandwidth of the electronic receiving unit. The DOP2000 model 2125 has 6 different bandwidth values. This defines a longitudinal dimension of the sampling volume from about 0.64 mm to 3.19mm in water. The DOP2000 defines the resolution as the distance between the center of adjacent sampling volumes. Its very fast processing capabilities allow a minimum distance between adjacent gates of 0.18mm (250ns). Distance between gates can be adjusted by step of 0.18mm.
