Assertion: sonar | /r/HasProperty | active
Facets:
value: primarily
type: DEGREE
value: in operation
type: LOCATION
Source sentences:
text: Such sonars are primarily active in operation.
text: Both radar and sonar are active systems; they provide a source of energy (electromagnetic and acoustic, respectively) to "illuminate" the terrain and can therefore operate both day and night.
text: All fishfinders operate as echo sounders, which is a form of active sonar.