Patent ID: 11899040
Assignee: HERE GLOBAL B.V.
Field: Measurement (Instruments)
Classification: CPC G | IPC G

Claim 7:
8. The method according to claim 7, wherein the data representative of the variation in the intensity of light emitted from at least two light sources comprises a spatial frequency F(Ls), the method further comprising one or more of the following:
obtaining a length l of the segment of the road;
detecting a light intensity signal Ls;
estimating an autocorrelation of the detected light intensity signal Ls:

RLM(τ)=Σn∈1 . . . NLM(n)LM(n−τ);

where N is the total number of samples in Ls;

estimating a number tC of signal samples of the detected signal in one cycle as:, t
      C
    
    =
    
      
        argmax
        τ
      
      ⁢
      
        
      
      ⁢
      
        R
        
          L
          M
        
      
    
  
  ;

estimating a number of cycles NCS LS at the road segment as:, N
      C
      S
    
    =
    
      N
      
        t
        C
      
    
  
  ,, and
estimating the frequency F(Ls) (e.g. in cycles per meter) as, F
    ⁡
    
      (
      
        L
        s
      
      )
    
  
  =
  
    
      
        N
        C
        S
      
      l
    
    .