Road weather prediction system and method

• US 20050010365A1
• Filed: 08/31/2002
• Published: 01/13/2005
• Est. Priority Date: 08/02/2001
• Status: Active Grant

• Current Assignee: International Business Machines Corporation
• Original Assignee: Entice Technology Limited
• Inventors: Thornes, John Edward, Chapman, Lee
• Granted Patent: US 7,089,115 B2
• Time in Patent Office: Days
• US Class Current: 702/3
• CPC Class Codes: G01S 19/14 specially adapted for specific applications
• CPC Class Codes: G01S 19/23 Testing, monitoring, correcting or calibrating of receiver elements
• CPC Class Codes: G01W 1/00 Meteorology

Abstract

In one aspect, the present invention relates to a method of determining the sky-view factor at a location. The method comprises the steps of receiving data from at least one global positioning satellite at the location, and comparing the data so obtained with a mathematical function. The function is derived from corresponding data obtained from reference locations at which the sky view factor is known, whereby to arrive at an approximation of the sky view factor at said location. In another aspect, the invention relates to a method for predicting the variation in temperatures over time at locations along a survey route, particularly a road network. The method comprises the steps of establishing a database for the survey route containing location specific geographical parameters, obtaining actual and forecast meteorological data and separately predicting the temperature at each location using energy balance equations. The predicted temperature calculated for each location is dependent upon the meteorological data and the geographical parameters for the location whose temperature is being predicted. The invention also discloses systems which relate to the above methods.

Claims

1. a method of determining the sky-view factor at a location, comprising the steps of:

(I) receiving data from at least one global positioning satellite at said location, and

(ii) comparing the data so obtained with a mathematical function derived from corresponding data obtained from reference locations at which the sky view factor is known, whereby to arrive at an approximation of the sky view factor at said location.

2. A method as claimed in claim 1, wherein the satellite data is selected from one or more of (I) the number of satellites in line of sight at said location, (ii) the sum of signal strengths of the or each satellite, and (iii) the dilution of precision value at said location.

3. A method as claimed in claim 1, wherein the mathematical function is obtained by plotting for each reference location the actual sky view factor against the satellite data corresponding to that to be received for the location whose sky view factor is to be determined, and fitting a curve through the plots, the mathematical function corresponding to the equation of the fitted curve.

4. A method as claimed in claim 1, wherein said reference locations are selected to be of a similar type to the location whose sky view factor is being determined.

5. A method as claimed in claim 1, wherein locations are classified according to their surroundings.

6. A method as claimed in claim 5, wherein locations are classified as urban, suburban, rural with leaves on trees or rural with leaves off trees.

7. A method as claimed in claim 5 which includes an initial step of receiving data from a user on the type of location at which the sky view factor is being determined, the mathematical function being derived only from reference locations of that same type.

8. A method as claimed in claim 5 in which data on the type of location at which the sky view factor is being determined is received from a database.

9. A method as claimed in claim 8, wherein said database is created from a satellite image.

10. A system for generating an approximate sky view factor at a location, said system comprising:

(I) data receiving means for receiving data from GPS satellites,

(ii) data storage means, (iii) a processor, and

(iv) output means selected from a visual display and/or printer for outputting the calculated sky view factor wherein

the data storage means holds a pre-defined mathematical function relating GPS satellite data at a location to the approximate sky view factor at that location, and in use, satellite data received by the data receiving means is transferred to the processor where a sky view factor for that location is calculated from said mathematical function.

11. A system as claimed in claim 10, wherein the data receiving means is adapted to receive satellite data selected from one or more of (I) the number of satellites in line of sight at said location, (ii) the sum of signal strengths of the or each satellite, and (iii) the dilution of precision value at said location.

12. A system as claimed in claim 10, wherein the predetermined mathematical function held in the data storage means is obtained by plotting for a plurality of reference locations the actual sky view factor against the satellite data corresponding to that to be received for the location whose sky view factor is to be determined, and fitting a curve through the plots, the mathematical function corresponding to the equation of the fitted curve.

13. A system as claimed in claim 12, additionally comprising a location classification database, and wherein the data storage means holds a pre defined mathematical function for each location class, such that in use, the appropriate pre-determined mathematical function to be used for a location is determined by the database classification of that location.

14. A system as claimed in claim 13, wherein said classification database is created from a satellite image.

16. A system as claimed in claim 10, wherein the calculated sky view factor is stored on the data storage means, and a data bus is provided for transmitting the calculated sky view factor to an external system.

17. A system as claimed in claim 10, wherein the data receiving means is constituted by a standard GPS receiver unit and the data storage means and processor are constituted by a computer.

18. A system as claimed in claim 10, wherein the data receiving means, the data storage means and the processor are integrated into a single hand-held unit.

25. A system for predicting temperatures at locations along a survey route, said system comprising:

(I) data storage means containing actual and forecast meteorological data, location specific geographical parameters and pre-defined energy balance equations,

(ii) a system for determining the sky view factor at locations along the survey route in accordance with claim 10, and

(iii) a processor for calculating the predicted temperature at each location on the survey route based on the meteorological data, sky view factor and location specific parameters input into the energy balance equations.

26. A system as claimed in claim 25, wherein said meteorological data held in the data storage means includes road surface temperature.

27. A system as claimed in claim 25, wherein said meteorological data held in said data storage means includes one or more of air temperature, dew-point, precipitation, cloud cover, cloud type and windspeed.

28. A system as claimed in claim 25, wherein said geographical parameters contained in said database are selected from latitude, longitude, altitude, an empirically derived cold air pooling index, sky view factor, screening, surface construction and landuse.

15. (Canceled).

19-24. -24. (Canceled).

29-31. -31. (Canceled).