Ultrasonic measurement apparatus and method for evaluating an ultrasonic signal

An ultrasonic measurement apparatus for a vehicle, comprising:

• a receiving device configured to receive an ultrasonic signal emitted by at least one of an in-vehicle and external ultrasonic transmitter and to determine and provide a measurement sequence relating to a time variation of period lengths of the received ultrasonic signal;
• a comparison device on which at least one reference sequence is stored and which is configured to compare the determined measurement sequence with the at least one reference sequence and to determine a comparison information item relating to a deviation of the determined measurement sequence from the at least one reference sequence;
• and
• an evaluation device configured to determine, based on the determined comparison information item, at least one of an information item relating to a signal form transmitted by the ultrasonic transmitter, a relative speed between the receiving device and the external ultrasonic transmitter, a relative speed of at least one reflecting object situated in a transmission path between the receiving device and the ultrasonic transmitter, and a shape feature of the at least one reflecting object;
• wherein the measurement sequence determined by the receiving device includes at least one of a sequence of positive period lengths of the ultrasonic signal, a sequence of negative period lengths of the ultrasonic signal, a sequence of positive period length deviations of the ultrasonic signal from a reference period length, a sequence of negative period length deviations of the ultrasonic signal from a reference period length, a sequence of frequencies of the ultrasonic signal, and a sequence of frequency deviations of the ultrasonic signal from a reference frequency.