Method and system for collecting traffic information using thermal sensing

• US 7,583,818 B2
• Filed: 09/19/2007
• Issued: 09/01/2009
• Est. Priority Date: 05/20/2003
• Status: Expired due to Term

• Current Assignee: HERE Global B.V. (Nokia Corporation)
• Original Assignee: Navteq North America LLC (Nokia Corporation)
• Inventors: Hegedus, Ildiko, Hegedus, Miklos Robert, Lasser, George
• Primary Examiner(s): Werner; Brian P
• Assistant Examiner(s): PAPPAS, CLAIRE X
• Application Number:
  US11/901,944
• Publication Number:
  US 20080010003A1
• Time in Patent Office: 713 Days
• Field of Search: 382/104, 701/117, 701/118, 701/119
• US Class Current: 382/104
• CPC Class Codes: G08G 1/0104 Measuring and analyzing of parameters relative to traffic conditions
• CPC Class Codes: G08G 1/04 using optical or ultrasonic detectors

Abstract

A method and system for collecting traffic data are disclosed. From a satellite or aircraft located at an altitude above a geographic area, a thermal image of the geographic area is obtained. Using a geographic database, the thermal image is matched to the positions of roads in the geographic area. The thermal image is used to determine traffic parameters, such as densities and speed, at specific locations along the roads.

Claims

1. A method of collecting data that indicate traffic conditions on roads in a geographic area comprising the steps of:

scanning the geographic area from an altitude above the geographic area to obtain a thermal image of the geographic area;

map matching, using a data processor, the thermal image to data from a geographic database, the date representing locations of roads in the geographic area;

filtering, using the data processor, the thermal image to remove thermal data that do not correspond to the roads and proximate areas thereof; and

using the filtered thermal image to determine at least one traffic parameter at the specific locations along said roads, using the data processor, wherein the map matching includes aligning locations in the thermal image with the locations of roads represented in the geographic database.

2. The method of claim 1 wherein the traffic parameter is related to heat differentials.

3. The method of claim 2 wherein the heat differentials are associated with heat generated by vehicles.

4. The method of claim 1 further comprising:

forming reports that indicate traffic parameters along said roads.

5. The method of claim 4 further comprising:

sending the reports indicating the traffic parameters to vehicles traveling along said roads.

6. The method of claim 1 wherein the traffic parameter includes density.

7. The method of claim 1 wherein the traffic parameter includes speed.

8. The method of claim 1 further comprising:

forming a thermal image video from a series of thermal images of the geographic area obtained over time.

9. The method of claim 8 further comprising:

deriving traffic speed from the thermal image video.

10. The method of claim 1 wherein the geographic database includes information about a legal speed limit corresponding to the respective roads.

11. A method of collecting data that indicate traffic conditions on roads in a geographic area comprising the steps of:

scanning the geographic area from an altitude above the geographic area to obtain a thermal image of the geographic area, wherein the thermal image is obtained with a satellite or aircraft;

matching, using a data processor, the thermal image to data representing roads from a road database, the data of the road database separate from image data obtained by the satellite or the aircraft;

determining, using the data processor, a change in temperature differential over time between a location on a road and an adjacent location off the road; and

using the chance in the temperature differential to determine, using the data processor, and increase or decrease in at least one traffic parameter at the location on the road.

12. A system for collecting data that indicate traffic conditions on roads in a geographic area, the system comprising:

a satellite-based thermal imaging camera that takes a thermal image of the geographic area from an altitude above the geographic area;

a geographic database that includes data indicating positions of roads located in the geographic area, the data of the geographic database separate from image data obtained by the satellite-based thermal imaging camera; and

a traffic data processor that receives the thermal image obtained by the satellite-based thermal imaging camera, uses the geographic database to align the data representing the positions of roads to locations in the thermal image, and determines at least one traffic parameter at specific locations along said roads using the thermal image,

wherein the at least one traffic parameter is determined based on calculating a temperature differential between a location on a road segment and an adjacent location off the road segment.

13. The system of claim 12 further comprising:

a communications system by which the thermal images are transmitted from the satellite to the traffic data processor.

14. The system of claim 12 further comprising:

a reporting system that transmits traffic reports derived from the traffic parameter to drivers in the geographic area.

15. The system of claim 12 wherein the traffic parameter includes density.

16. The system of claim 12 wherein the traffic parameter includes speed.

17. A system for collecting data that indicate traffic conditions on roads in a geographic area, the system comprising:

means for obtaining thermal images of the geographic area from an altitude above the geographic area;

database means for containing data indicating locations of roads in the geographic area; and

means for determining traffic conditions along said roads by map matching the thermal images to the roads indicated by the data contained in the database means and by removing thermal data corresponding to a location away from the roads.

18. The system of claim 17 wherein said means for obtaining thermal images includes a satellite.

19. The system of claim 17 further comprising:

means for distributing traffic reports indicating the traffic conditions to end user.

20. A method of collecting data that indicate traffic conditions on roads in a geographic area comprising the steps of:

scanning the geographic area from an altitude above the geographic area to obtain a thermal image of the geographic area;

matching, using a data processor, the thermal image to data from a geographic database, representing positions of roads in the geographic area;

determining, using the data processor, a temperature differential between a location on a road segment of the roads and a proximate location off the road segment based on the matching; and

determining, using the data processor, at least on traffic parameter along the road segment as a function of the temperature differential.