Method and system for determining possible geographic positions of an assumed undetected target

Patent metadata

Field	Value
Publication number	US-10853644-B2
Application number	US-201716642862-A
Country	US
Kind code	B2
Filing date	Aug 31, 2017
Priority date	Aug 31, 2017
Publication date	Dec 1, 2020
Grant date	Dec 1, 2020

Abstract

A sensor surveillance system ( 100 ) and a method for determining possible geographic positions of at least one assumed undetected target ( 1 a - n ) within a geographic volume of interest ( 200 ) is provided, wherein for a first point in time ti the following steps are performed: dividing the geographic volume of interest ( 200 ) into sections ( 10 ); assuming the existence of an assumed undetected target ( 1 a - n ) at a geographic position within each section ( 10 ); and initiating the creation of a pattern ( 2 ) defining at least one possible geographic position of the assumed undetected target, said pattern extends at least partially around the geographic position of the assumed undetected target ( 1 a - n ); wherein the geographic extension of said pattern is determined based on: the category of the assumed undetected target ( 1 a - n ); and the amount of time that has passed from the first point in time t 1 . Further, for a second point in time t 2 the following steps are performed: determining geographic locations ( 205 ) within said geographic volume of interest ( 200 ) from where sensor signals show absence of targets; and removing the pattern ( 2 ) from the geographic locations ( 205 ) from where sensor signals show absence of targets.

First claim

The invention claimed is:

1. A method for determining possible geographic positions of at least one assumed undetected target within a geographic volume of interest, the method comprising:
for a first point in time t 1 ,
dividing, by at least one processor, the geographic volume of interest into sections;
assuming, by the at least one processor, an existence of an assumed undetected target at a geographic position within each section of the sections; and
initiating, by the at least one processor, creation of a pattern defining at least one possible geographic position of the assumed undetected target, wherein the pattern geographically extends at least partially around the geographic position of the assumed undetected target;
wherein the geographic extension of the pattern is determined based on:
a category of the assumed undetected target; and
an amount of time that has passed from the first point in time t 1 ; and

for a second point in time t 2 ,
determining, by the at least one processor, geographic locations within the geographic volume of interest from where sensor signals show absence of targets; and
removing, by the at least one processor, the pattern from the geographic locations from where sensor signals show absence of targets;
wherein at least one sensor of a sensor surveillance system is controlled based on the pattern.

2. The method according to claim 1 , wherein the method is performed repeatedly, and for each further first point in time t 1i subsequent the first point in time t 1 , new sections are only assumed along a border of the geographic volume of interest.

3. The method according to claim 1 , further comprising: at each point in time subsequent the first point in time t 1 ,
comparing properties of each pattern; and
merging parts of those patterns for which a comparison fulfils a predetermined criteria.

4. The method according to claim 1 , wherein a separate pattern is created for each category of the assumed undetected target.

5. The method according to claim 1 , wherein blind spots within the geographic volume of interest are determined based on the pattern.

6. The method according to claim 1 , wherein the geographic extension of the pattern is further based on characteristics of surroundings of the geographic position of the assumed undetected target at each point in time.

7. The method according to claim 1 , wherein the category of the assumed undetected target is one of a human, a land borne vehicle, a waterborne vehicle, or an airborne vehicle.

8. The method according to claim 1 wherein at least one sensor of the sensor surveillance system is controlled to scan a certain geographic volume at least at those geographic positions where the pattern of the assumed undetected target is present.

9. The method according to claim 1 , further comprising: calculating a probability of a presence of the assumed undetected target for at least one part of the pattern at each point in time.

10. The method according to claim 9 , wherein the probability of the presence of the assumed undetected target for the at least one part of the pattern is based on at least one of:
the category of the assumed undetected target;
surroundings of the geographic position where the assumed undetected target is assumed to be situated at each point in time; or
an ability of the sensor in the sensor surveillance system scanning a certain geographic volume to detect the assumed undetected target in the geographic volume.

11. The method according to a claim 10 wherein at least one sensor of the sensor surveillance system is controlled based on the probability of the presence of an assumed undetected target associated with each part of the pattern.

12. The method according to claim 1 , wherein geographic positions of a pattern for an assumed undetected target are related to a grid.

13. A sensor surveillance system configured for determining possible geographic positions of at least one assumed undetected target within a geographic volume of interest, the system comprising:
a central control unit comprising at least one processor; and
at least one sensor arranged to scan and detect targets in a certain geographic volume within the geographic volume of interest,
wherein the central control unit is arranged to perform: at a first point in time t 1 ,
dividing the geographic volume of interest into sections;
assuming an existence of an assumed undetected target at a geographic position within each section of the sections; and
initiating a creation of a pattern defining at least one possible geographic position of the assumed undetected target, wherein the pattern geographically extends at least partially around the geographic position of the assumed undetected target; and

wherein the geographic extension of the pattern is determined based on:
a category of the assumed undetected target; and
an amount of time that has passed from the first point in time t 1 ; and

at a second point in time t 2 ,
determining geographic locations within the geographic volume of interest ( 200 ) from where signals from the sensor show absence of targets; and
removing the pattern from those geographic locations from where the signals from the sensor show absence of targets;

wherein the central control unit is arranged to control at least one sensor of the sensor surveillance system based on the pattern.

14. The sensor surveillance system according to claim 13 , wherein the central control unit is arranged to perform repeatedly, and wherein, for each further first point in time t 1i subsequent the first point in time t 1 , new sections are only assumed along a border of the geographic volume of interest.

15. The sensor surveillance system according to claim 13 , wherein the central control unit is arranged for performing, at each point in time subsequent the first point in time t 1 :
comparing properties of each pattern; and
merging parts of the patterns for which a comparison fulfils a predetermined criteria.

16. The sensor surveillance system according to claim 13 , wherein the central control unit is configured to create a separate pattern for each category of the assumed undetected target.

17. The sensor surveillance system according to claim 13 , wherein the central control unit is configured to determine blind spots within the geographic volume of interest based on the pattern.

18. The sensor surveillance system according to claim 13 , wherein the central control unit is arranged to further base the geographic extension of the pattern on characteristics of surroundings of the geographic position of the assumed undetected target at each point in time.

19. The sensor surveillance system according to claim 13 , wherein the category of the assumed undetected target is one a human, a land borne vehicle, a waterborne vehicle, or an airborne vehicle.

20. The sensor surveillance system according to claim 13 , wherein the central control unit is arranged to control at least one sensor of the sensor surveillance system to scan a certain geographic volume at least at those geographic positions where a pattern of an assumed undetected target is present.

21. The sensor surveillance system according to claim 13 , wherein the central control unit is arranged for performing: calculating a probability of a presence of an assumed undetected target for at least one part of the pattern at each point in time.

22. The sensor surveillance system according to claim 21 , wherein the centra

Assignees

• Saab Ab

Inventors

• Dicander Fredrik

Classifications

• G01S13/86 Primary

  Combinations of radar systems with non-radar systems, e.g. sonar, direction finder · CPC title

• G06V20/52

  Surveillance or monitoring of activities, e.g. for recognising suspicious objects (recognising microscopic objects G06V20/69) · CPC title

• G06V10/422

  for representing the structure of the pattern or shape of an object therefor · CPC title

• G01S13/87

  Combinations of radar systems, e.g. primary radar and secondary radar · CPC title

• G01S13/72

  for two-dimensional [2D] tracking, e.g. combination of angle and range tracking, track-while-scan radar · CPC title