Imaging system

• US 9,151,839 B2
• Filed: 04/11/2011
• Issued: 10/06/2015
• Est. Priority Date: 04/15/2010
• Status: Active Grant

• Current Assignee: Smiths Detection Ireland Limited
• Original Assignee: Smiths Detection Ireland Limited
• Inventors: Crowley, Michael, Entchev, Emil, Abdillah, Mohammed Ben
• Primary Examiner(s): Brainard, Timothy A
• Application Number:
  US13/639,711
• Publication Number:
  US 20130093611A1
• Time in Patent Office: 1,639 Days
• Field of Search: 342/75
• US Class Current: 1/1
• CPC Class Codes: G01S 13/887 for detection of concealed objects, e.g. contraband or weapons
• CPC Class Codes: G01S 7/4026 Antenna boresight
• CPC Class Codes: G01S 7/403 in azimuth, i.e. in the horizontal plane
• CPC Class Codes: G01S 7/4034 in elevation, i.e. in the vertical plane

Abstract

An imaging system (1) comprises a transmitter (3, 6), a receiver (3, 4, 6), an antenna array (2); and a controller (4, 5, 10, 11) for directing the transmitter, the receiver, and the antenna array to scan a volume containing an object. The controller has multiple distributed processors (15) to calculate antenna control pattern data during run-time. The processor (4, 5) assesses misalignment of antennae using a receiver placed in the imaging volume, and monitors level of energy received by the receiver and compares it with a reference energy level. Also, the controller performs on-the-fly modification of antenna control pattern data according to real time conditions such as mechanical misalignment of the transmitter, the receiver, or of one or more antennas. The controller may generate three-dimensional offset vectors to provide a profile of the offset across the scan volume, and the position of an antenna may be moved to compensate for the mechanical misalignment.

Claims

1. An imaging system comprising:

(a) a transmitter,

(b) a receiver,

(c) an antenna array, and

(d) a controller for directing the transmitter, the receiver, and the antenna array to scan a volume containing an object;

wherein the transmitter is adapted to transmit radiation at the antenna array;

wherein the antenna array is adapted to reflect radiation received from the transmitter at the volume containing the object, and to reflect radiation reflected by the object at the receiver;

wherein the receiver is adapted to receive radiation reflected from the antenna array;

wherein the controller is adapted to;

(i) calculate antenna control pattern data at start-up or during run-time,

(ii) assess antenna misalignment, and

(iii) perform on-the-fly modification of antenna control pattern data according to real time conditions;

wherein said conditions include mechanical misalignment of the transmitter, or of the receiver, or of one or more antennas.

2. The imaging system as claimed in claim 1, wherein the controller comprises a plurality of distributed antenna control circuits, each adapted to calculate antenna control pattern data.

3. The imaging system as claimed in claim 1, wherein the controller comprises a plurality of distributed antenna control circuits, each adapted to calculate antenna control pattern data;

and wherein the controller comprises a digital receiver adapted to receive commands from a host computer and to route said commands to the antenna control circuits.

4. The imaging system as claimed in claim 1, wherein the controller comprises a plurality of distributed antenna control circuits, each adapted to calculate antenna control pattern data wherein each said antenna control circuit comprises a processor for distributed calculation of the antenna control pattern data.

5. The imaging system as claimed in claim 1, wherein the controller comprises a plurality of distributed antenna control circuits, each adapted to calculate antenna control pattern data wherein each said antenna control circuit comprises a processor for distributed calculation of the antenna control pattern data;

and wherein said processor comprises a field programmable gate array processor or an application-specific integrated circuit.

6. The imaging system as claimed in claim 1, wherein the controller is adapted to calculate the pattern data without need for non-volatile memory.

7. The imaging system as claimed in claim 1, wherein the controller is adapted to output the pattern data without need for a buffer memory.

8. The imaging system as claimed in claim 1, wherein the controller is adapted to assess misalignment of antennae using a receiver placed in the imaging volume, and to monitor level of energy received by the receiver and compare it with a reference energy level.

9. The imaging system as claimed in claim 1, wherein the controller is adapted to assess antenna misalignment using a test object placed in the imaging volume and monitoring energy received by the receiver due to presence of the test object.

10. The imaging system as claimed in claim 1, wherein the controller is adapted to insert, according to real time conditions, an offset value in each of three space dimensions when calculating distances.

11. The imaging system as claimed in claim 1, wherein the controller is adapted to insert, according to real time conditions, an offset value in each of three space dimensions when calculating distances;

and wherein the controller is adapted to insert said offset when determining position of a destination scan volume element.

12. The imaging system as claimed in claim 1, wherein the controller is adapted to insert, according to real time conditions, an offset value in each of three space dimensions when calculating distances;

and wherein the controller is adapted to insert said offset to indicate the relative position of an antenna with respect to the antenna array plane.

13. The imaging system as claimed in claim 1, wherein the controller is adapted to insert, according to real time conditions, an offset value in each of three space dimensions when calculating distances;

and wherein the controller is adapted to insert said offset to indicate the relative position of a transceiver horn with respect to the antenna array plane.

14. The imaging system as claimed in any of claim 1, wherein the controller is adapted to insert, according to real time conditions, an offset value in each of three space dimensions when calculating distances;

and wherein the controller is adapted to change the shape of the scan volume according to real time conditions, in order to compensate for mechanical misalignment.

15. The imaging system as claimed in claim 1, wherein the controller is adapted to insert, according to real time conditions, an offset value in each of three space dimensions when calculating distances;

and wherein the controller is adapted to change the shape of the scan volume according to real time conditions, in order to compensate for mechanical misalignment; and

wherein the controller is adapted to generate a plurality of three-dimensional offset vectors to provide a profile of the offset across the scan volume.

16. An imaging system comprising:

a transmitter,

a receiver,

an antenna array, and

a controller for directing the transmitter, the receiver, and the antenna array to scan a volume containing an object;

wherein the transmitter is adapted to transmit radiation at the antenna array;

wherein the antenna array is adapted to reflect radiation received from the transmitter at the volume containing the object, and to reflect radiation reflected by the object at the receiver;

wherein the receiver is adapted to receive radiation reflected from the antenna array;

wherein the controller is adapted to;

(i) calculate antenna control pattern data at start-up or during run-time,

(ii) assess antenna misalignment, and

(iii) perform on-the-fly modification of antenna control pattern data according to real time conditions;

wherein said conditions include mechanical misalignment of the transmitter, or of the receiver, or of one or more antennas; and

wherein the controller is adapted to assess misalignment of antennae using a receiver placed in the imaging volume, and to monitor level of energy received by the receiver and compare it with a reference energy level.

17. An imaging system comprising:

a transmitter,

a receiver,

an antenna array, and

a controller for directing the transmitter, the receiver, and the antenna array to scan a volume containing an object;

wherein the transmitter is adapted to transmit radiation at the antenna array;

wherein the antenna array is adapted to reflect radiation received from the transmitter at the volume containing the object, and to reflect radiation reflected by the object at the receiver;

wherein the receiver is adapted to receive radiation reflected from the antenna array;

wherein the controller is adapted to;

(i) calculate antenna control pattern data at start-up or during run-time,

(ii) assess antenna misalignment; and

(iii) perform on-the-fly modification of antenna control pattern data according to real time conditions;

wherein said conditions include mechanical misalignment of the transmitter, or of the receiver, or of one or more antennas; and

wherein the controller is adapted to assess antenna misalignment using a test object placed in the imaging volume and monitoring energy received by the receiver due to presence of the test object.