Apparatus and Imaging Method with Synthetic Aperture for Determining an Incident Angle and/or a Distance

• US 20100324864A1
• Filed: 06/23/2010
• Published: 12/23/2010
• Est. Priority Date: 06/23/2009
• Status: Active Grant

• Current Assignee: Symeo GmbH (indie Semiconductor, Inc.)
• Original Assignee: Symeo GmbH (indie Semiconductor, Inc.)
• Inventors: Max, Stephan, Vossiek, Martin
• Granted Patent: US 8,299,959 B2
• Time in Patent Office: Days
• US Class Current: 702/151
• CPC Class Codes: G01S 13/42 Simultaneous measurement of distance and other co-ordinates indirect measurement G01S13/46
• CPC Class Codes: G01S 13/904 SAR modes
• CPC Class Codes: G01S 15/8904 using synthetic aperture techniques

Abstract

The invention relates to an imaging method with synthetic aperture for determining an incident angle and/or a distance of a sensor from at least one object in space, wherein at each of a number of aperture points one echo profile is sensed. Advantageously, for several angles assumed as the incident angle, one phase correction value and/or one distance correction value is calculated, adapted profiles are generated based on the echo profiles by adapting the phase with the phase correction value for each assumed angle and/or by shifting the distance with the distance correction value, for the assumed angle, the adapted profiles are summed or integrated, and a probability distribution is derived, and a probability value for the incident angle and/or for the distance is determined therefrom. A determination of the incident angle is also possible independently of the distance, wherein it is possible to only consider velocities or accelerations.

Claims

1. An imaging method with a synthetic aperture for determining at least one of an incident angle and a distance of a sensor from at least one object in space, comprising:

sensing, at a number of aperture points, one respective echo profile;

calculating at least one of one phase correction value and one distance correction value for each of a plurality of assumed angles as the at least one incident angle;

generating adapted profiles based the echo profiles by at least one of adapting the phase by the phase correction value for each of the assumed angles and shifting the distance by the distance correction value;

forming a probability distribution for the assumed angles from the adapted profiles; and

determining at least one of a probability value for the incident angle and the distance from the probability distribution.

2. The method according to claim 1, further comprising:

summing up or integrating, for the assumed angles, the adapted profiles; and

forming the probability distribution therefrom.

3. The method according to claim 1, further comprising calculating at least one of the phase correction values and the distance correction values on the basis of the aperture points from the position data of the aperture.

4. The method according to claim 1, further comprising generating an adapted echo profile as the adapted profile by at least one of adapting the phase of the echo profiles for each assumed angle by the phase correction value and shifting the distance by the distance correction value.

5. The method according to claim 1, further comprising separating the probability function into one-dimensional probability functions by summing-up or by determining maxima.

6. The method according to claim 1, further comprising:

forming a number of phase velocity profiles from the echo profiles; and

determining phase angle velocities as their argument.

7. The method according to claim 6, further comprising calculating the at least one angle assumed as the incident angle in dependence on a relative movement velocity between the wave-based sensor and the object and, in each case, calculating one complex phase correction value as a correction in dependence on a phase variation based on a velocity difference.

8. The method according to claim 6, further comprising summing up or integrating, for each assumed angle, the phase-corrected phase velocity profiles are summed-up or integrated to form velocity probability density functions.

9. The method according to claim 1, further comprising calculating the at least one angle assumed as the incident angle in dependence on a relative acceleration between the wave-based sensor and the object, and, in each case, calculating one complex phase correction value as a correction in dependence on a phase variation based on an acceleration difference.

10. The method according to claim 9, further comprising:

forming a number of phase acceleration profiles from the echo profiles; and

determining an acceleration vector as their argument.

11. The method according to claim 9, further comprising summing of or integrating, for each assumed angle, the phase-corrected phase acceleration profiles to form an acceleration probability distribution.

12. The method according to claim 9, further comprising performing an analytical calculation of the extreme values of the one-dimensional acceleration probability distribution or of the zero crossing of the phase of the one-dimensional acceleration probability distribution.

13. The method according to claim 1, further comprising, for sensing the echo profile, transmitting a signal from the sensor to the at least one object, and the at least one object in space includes a transponder, or is configured as a transponder, which receives the signal and transmits a modified signal in dependence on the signal as a signal coming from the object, back to the sensor, which is used as a signal received in the sensor as the echo profile.

14. An apparatus comprising a wave-based sensor for sensing a sequence of echo signals of an object, and comprising at least one of a logic element and a processor that accesses at least one program as a controller, wherein at least one of the logic and the processor is configured for carrying out a method according to claim 1 for determining at least one of an incident angle and a distance of a sensor from at least one object in space.

15. The apparatus according to claim 14, comprising a memory or an interface to a memory, wherein the program is stored in the memory.

16. The apparatus according to claim 14, wherein the object includes a transponder or is configured as a transponder.