Adaptive selection of ultrasound frequency

A method comprising:

• outputting, by a transducer, a first ultrasonic signal that bounces off a target and produces an ultrasonic echo signal;
• receiving, by the transducer, the ultrasonic echo signal;
• converting, by the transducer, the ultrasonic echo signal to an electrical signal that spans a frequency range, the electrical signal representing a first image of the target;
• obtaining a set of two or more sub-signals from the electrical signal, wherein each of the sub-signals spans a respective frequency sub-range of the frequency range;
• computing, for each of the sub-signals, a respective plurality of spatial coherence metric values,
• determining respective values of a conspicuity metric for each of the sub-signals based on the respective plurality of spatial coherence metric values;
• selecting a frequency sub-range of the respective frequency sub-ranges based on the conspicuity metric values;
• and
• generating a second ultrasonic signal based on the selected frequency sub-range, the second ultrasonic signal for obtaining at least one of a second image of the target or an image of a different target.