Sensor head

• US 8,842,035 B2
• Filed: 04/06/2011
• Issued: 09/23/2014
• Est. Priority Date: 04/08/2010
• Status: Active Grant

• Current Assignee: L3harris Fuzing and Ordnance Systems Incorporated
• Original Assignee: L-3 Communications Security & Detection Systems, Inc. (Leidos Holdings, Inc.)
• Inventors: Duvoisin, Herbert III, Torres-Rosario, Juan Antonio, Sentelle, Christopher Gary, Carlson, Douglas O., Holman, Glen A., Trishaun, Marquette
• Primary Examiner(s): Sotomayor, John B
• Application Number:
  US13/081,153
• Publication Number:
  US 20140022106A1
• Time in Patent Office: 1,266 Days
• Field of Search: 342/22, 342/27, 342/90, 342/196, 324/326, 324/329
• US Class Current: 342/22
• CPC Class Codes: G01S 13/0209 Systems with very large relative bandwidth, i.e. larger than 10 %, e.g. baseband, pulse, carrier-free, ultrawideband
• CPC Class Codes: G01S 13/347 using more than one modulation frequency
• CPC Class Codes: G01S 13/86 Combinations of radar systems with non-radar systems, e.g. sonar, direction finder
• CPC Class Codes: G01S 13/885 for ground probing prospecting or detecting using electromagnetic waves G01V3/12
• CPC Class Codes: G01S 7/354 Extracting wanted echo-signals Doppler systems G01S13/50
• CPC Class Codes: G01S 7/412 based on a comparison between measured values and known or stored values
• CPC Class Codes: G01V 3/12 operating with electromagnetic waves operating with millimetre waves G01V8/005

Abstract

An apparatus includes an extendable wand, and a sensor head coupled to the wand. The sensor head includes a continuous wave metal detector (CWMD) and a radar. When the wand is collapsed, the wand and the sensor head collapse to fill a volume that is smaller than a volume filled by the sensor head and the wand when the wand is extended. Frequency-domain data from a sensor configured to sense a region is accessed, the frequency-domain data is transformed to generate a time-domain representation of the region, a first model is determined based on the accessed frequency-domain data, a second model is determined based on the generated time-domain representation, the second model being associated with a particular region within the sensed region, and a background model that represents a background of the region is determined based on the first model and the second model.

Claims

1. A method comprising:

accessing frequency-domain data from a sensor configured to sense a region;

transforming the frequency-domain data to generate a time-domain representation of the region;

determining a first model based on the accessed frequency-domain data;

determining a second model based on the generated time-domain representation, the second model being associated with a particular region within the sensed region; and

determining a background model that represents a background of the region based on the first model and the second model.

2. The method of claim 1, further comprising:

receiving additional frequency-domain data from the sensor after determining the background model;

comparing the additional frequency-domain data to the background model;

determining that the additional frequency-domain data represents a target based on the comparison; and

triggering an alarm based on the determination that the additional frequency-domain data represents a target.

3. The method of claim 1, wherein accessing frequency-domain data from a sensor configured to sense a region comprises accessing the frequency-domain data from a ground penetrating radar configured to sense the region.

4. The method of claim 1, further comprising determining whether the first model and the second model include outliers.

5. The method of claim 1, wherein the first model comprises a ground coupling model that represents frequencies emphasized by operator motion, and the second model comprises a model that represents a surface of the ground and one or more target models, each target model associated with a particular depth beneath the surface.

6. The method of claim 1, further comprising:

receiving additional frequency-domain data from the sensor after determining the background model;

determining whether the additional frequency-domain data is an outlier; and

re-computing the background model using the additional frequency-domain data if the additional frequency-domain data is an outlier.

7. A system comprising:

a sensor configured to sense a region at each of multiple frequencies;

a processor coupled to the sensor and an electronic storage, the electronic storage comprising instructions that, when executed, cause the processor to;

receive frequency-domain data from the sensor;

transform the frequency-domain data to generate a time-domain representation of the accessed frequency-domain data;

determine a first model based on the accessed frequency-domain data;

determine a second model based on the generated time-domain representation, the second model being associated with a particular region within the sensed region; and

determine a background model that represents a background of the region, based on the first model and the second model.

8. The system of claim 7, wherein the sensor comprises a ground penetrating radar.

9. The system of claim 7, wherein the sensor comprises a continuous wave metal detector (CWMD).

10. The system of claim 9, wherein the sensor further comprises a ground penetrating radar.

11. The system of claim 10, wherein the ground penetrating radar and the continuous wave metal detector are received in a single sensor head.

12. The system of claim 7, wherein the sensor is mounted on a platform that is configured to be held and manually operated by a human operator.

13. The system of claim 11, wherein the CWMD transmits and receives radiation at twenty-one or more different frequencies.