Target value detection for an unmanned aerial vehicle is described. The unmanned aerial vehicle includes a first transducer that transmits a first ultrasonic signal and receives a first ultrasonic response and a second transducer that transmits a second ultrasonic signal and receives a second ultrasonic response. The second transducer has a wider beam pattern than the first transducer. Determinations are made as to whether either or both of the first or second ultrasonic responses includes a target value within range areas associated with the respective beam patterns of the first and second transducers. A confidence value is generated based on the determinations. The target value is reflected from an object and the confidence value indicates a likelihood of a position of the unmanned aerial vehicle with respect to the object.