Dynamic aperture
Encyclopedia
Dynamic aperture is a term in acoustics
used very much like aperture
in photography. The arrays in side-scan sonar
can be programmed to transmit just a few elements at a time or all the elements at once. The more elements transmitting, the narrower the beam and the better the resolution
.
The ratio of the aperture size to the imaging depth is known as the F-number. Dynamic aperture is keeping this number constant by growing the aperture with the imaging depth until the physical aperture cannot be increased. A modern medical ultrasound machine has a typical F-number of 0.5.
Side Scan Sonar systems produce images by forming angular “beams”. Beam width is determined by length of the sonar array, narrower beams resolve finer detail. Longer arrays with narrower beams provide finer spatial resolution.
Acoustics
Acoustics is the interdisciplinary science that deals with the study of all mechanical waves in gases, liquids, and solids including vibration, sound, ultrasound and infrasound. A scientist who works in the field of acoustics is an acoustician while someone working in the field of acoustics...
used very much like aperture
Aperture
In optics, an aperture is a hole or an opening through which light travels. More specifically, the aperture of an optical system is the opening that determines the cone angle of a bundle of rays that come to a focus in the image plane. The aperture determines how collimated the admitted rays are,...
in photography. The arrays in side-scan sonar
Side-scan sonar
Side-scan sonar is a category of sonar system that is used to efficiently create an image of large areas of the sea floor...
can be programmed to transmit just a few elements at a time or all the elements at once. The more elements transmitting, the narrower the beam and the better the resolution
Audio bit depth
In digital audio, bit depth describes the number of bits of information recorded for each sample. Bit depth directly corresponds to the resolution of each sample in a set of digital audio data...
.
The ratio of the aperture size to the imaging depth is known as the F-number. Dynamic aperture is keeping this number constant by growing the aperture with the imaging depth until the physical aperture cannot be increased. A modern medical ultrasound machine has a typical F-number of 0.5.
Side Scan Sonar systems produce images by forming angular “beams”. Beam width is determined by length of the sonar array, narrower beams resolve finer detail. Longer arrays with narrower beams provide finer spatial resolution.