Method for operating an ultrasonic sensor, computer program product, ultrasonic sensor system and vehicle

An ultrasonic sensor system comprising:

• an ultrasonic sensor comprising a membrane and an exciter element for exciting the membrane and for detecting a vibration of the membrane;
• a storage unit for storing calibration data,
• wherein the calibration data comprises information about a first frequency response of the ultrasonic sensor in a sending direction depending on a membrane excitation frequency at different membrane temperatures and information about a second frequency response of the ultrasonic sensor in a receiving direction depending on a membrane vibration frequency at different membrane temperatures;
• a temperature determination unit for determining a current membrane temperature;
• a sensitivity determination unit for determining a sensitivity of the ultrasonic sensor using the first frequency response at the current membrane temperature and the second frequency response at the current membrane temperature;
• and
• a control unit for controlling an electric current provided to the exciter element and a gain of the ultrasonic sensor based on a difference between the determined sensitivity and a prestored sensitivity.