Methods for detecting humans

1. A method of detecting a human, comprising:

(a) measuring the ultrasonic signal emitted from human footsteps;

(b) measuring the human body motion Doppler signature;

(c) reviewing the measurements of steps (a) and (b); and

(d) determining the presence of a human.

2. The method of claim 1 , wherein steps (a) and (b) are performed simultaneously.

3. The method of claim 1 , wherein the determination step (d) indicates the presence of a human in an enclosure.

4. The method of claim 1 , wherein the determination step (d) indicates the presence of a human in an outdoor area.

5. The method of claim 1 , wherein the measurement step (a) comprises the utilization of microphone sensors for human footstep detection.

6. The method of claim 5 , wherein the microphone sensors comprise ultrasonic microphone sensors.

7. The method of claim 6 , wherein the ultrasonic microphones measure frequencies in a narrow band frequency range.

8. The method of claim 7 , wherein the ultrasonic microphones measure frequencies in the range of about 24-26 kHz.

9. The method of claim 6 , wherein the ultrasonic microphones measure frequencies in the range of about 24-26 kHz.

10. The method of claim 7 , wherein the ultrasonic microphones measure at least one of the toe slap or weight transfer portions of the human footstep signature.

11. The method of claim 1 , wherein the review step (c) includes the measurement of the sound pressure signature from human footstep signals.

12. The method of claim 11 , wherein the review step (c) comprises a Fourier spectrum mathematical operation of the sound pressure signal.

13. The method of claim 12 , wherein the Fourier spectrum is considered as a function of time and a time/frequency analysis is conducted.

14. The method of claim 1 , wherein the measure step (b) comprises transmitting waves to a human body, and receiving the reflected or back-scattered waves.

15. The method of claim 14 , wherein the reflected waves are frequency-modulated by time-varying motions of human body parts.

16. The method of claim 1 , wherein the measurement step (b) comprises a transmitter to emit a carrier signal and a receiver to recognize a human motion modulated carrier signal.

17. The method of claim 14 , wherein the transmitting waves are ultrasonic waves.

18. The method of claim 14 , wherein the transmitting waves are chosen from sound and electromagnetic, radar, ultrasound, laser, IR, or terahertz waves.

19. The method of claim 14 , wherein Doppler signature is measured by transmitting and receiving ultrasonic waves of a resonance frequency of about 20 kHz to about 10 kHz.

20. The method of claim 19 , wherein the frequency of transmitting ultrasonic waves is about 40 kHz.

21. The method of claim 16 , wherein the human motion modulated carrier signal comprises a recognition of a frequency shift of human body motion when the arms and legs move characteristically in relation to the torso.

22. The method of claim 1 , wherein step (a) comprises measuring the timing between the footstep signal, and step (b) comprises measuring Doppler shifts associated with appendage motion, and step (c) comprises a comparison of the two to determine the presence of a human.

23. The method of claim 1 , wherein steps (c) and (d) comprise utilization of the time-frequency analysis to review data obtained in steps (a) and (b) and compare that data to a standard value.

24. The method of claim 23 , wherein the Markov chain method is used for time-frequency analysis.

25. The method of claim 1 , wherein the method is applied to walking or running vertebrate animals.

26. The method of claim 1 , further comprising the steps of (1) time frequency localization of footstep signals and (2) extraction of the specific periodicity in footstep signals.

27. The method of claim 26 , wherein (1) includes parallel band pass filtering.

28. The method of claim 26 , wherein (2) includes the application of a short time Fourier transform (STFT).