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recintro

PURPOSE ^

Info about RECDEMO: A statistical procedure for reconstruction of 1D signals.

SYNOPSIS ^

recintro

DESCRIPTION ^

  RECINTRO  Info about RECDEMO: A statistical procedure for reconstruction of 1D signals. 
 
  The files in this directory can reproduce the figures in the 
  article of 
  
  Brodtkorb, P.A., Myrhaug, D. and Rue, H (1999)
  'Joint distribution of wave height and wave crest velocity
   from reconstructed data.'
   in Proceedings of 9th ISOPE Conference, Vol III, pp 66-73
  
  
  The paper shows a method for reconstruction of missing and or spurious 
  data points of a recorded time series by using a transformed Gaussian
  process. The application of the result is illustrated by fitting a
  joint distribution to the maximum of the crest front velocity and crest back velocity
  (V = max(Vcf,Vcb)) and the corresponding wave height (H = Hd or Hu)
  obtained from the reconstructed data set. The joint distribution seem to be physically 
  sound and much better described using the reconstructed than the 
  original time series. (Note that the extracted data are normalized with 
  the rms values, i.e., v=V/Vrms and h=H/Hrms)
  The joint probability distribution given as the product of the 
  Rayleigh distribution of wave heights and the Weibull distribution 
  for the conditional crest velocity (v) given wave height (h) seem to be
  a reasonable model.
 
   DATA: GFAKS89.DAT 
  ~~~~~~~~~~~~~~~~~~~
  The wave data considered was measured 24th December 1989 at the Gullfaks C platform  
  in the North Sea from 17.00 to 21.20. The period from 20.00 to 20.20
  is missing and contains NaNs.  The  water depth of  218 m is  
  regarded as deep water for the most  important wave components.
  There are two EMI laser sensors named 219 and 220. This data set is 
  obtained from sensor 219, which is  located in the Northwest
  corner  approximately two platform leg diameters away from   
  the closest leg.  
    Thus the wave elevation is not expected  to be significantly 
  affected by  diffraction effects for incoming waves in the western sector.   
  The wind direction for this period is from the south.
  Some  difficulties in calibration of the instruments have been reported
  resulting in several consecutive measured values being equal or nearly equal 
  in the observed data set.
   
  Hm0 = 6.8m, Tm02 = 8s, Tp = 10.5 Tp2=19
 
  Wind data from Statfjord A, 1989 are also given to justify the
  assumption that the data may be regarded as stationary.

CROSS-REFERENCE INFORMATION ^

This function calls: This function is called by:

SOURCE CODE ^

001 function recintrorecintro
002 % RECINTRO  Info about RECDEMO: A statistical procedure for reconstruction of 1D signals. 
003 %
004 % The files in this directory can reproduce the figures in the 
005 % article of 
006 % 
007 % Brodtkorb, P.A., Myrhaug, D. and Rue, H (1999)
008 % 'Joint distribution of wave height and wave crest velocity
009 %  from reconstructed data.'
010 %  in Proceedings of 9th ISOPE Conference, Vol III, pp 66-73
011 % 
012 % 
013 % The paper shows a method for reconstruction of missing and or spurious 
014 % data points of a recorded time series by using a transformed Gaussian
015 % process. The application of the result is illustrated by fitting a
016 % joint distribution to the maximum of the crest front velocity and crest back velocity
017 % (V = max(Vcf,Vcb)) and the corresponding wave height (H = Hd or Hu)
018 % obtained from the reconstructed data set. The joint distribution seem to be physically 
019 % sound and much better described using the reconstructed than the 
020 % original time series. (Note that the extracted data are normalized with 
021 % the rms values, i.e., v=V/Vrms and h=H/Hrms)
022 % The joint probability distribution given as the product of the 
023 % Rayleigh distribution of wave heights and the Weibull distribution 
024 % for the conditional crest velocity (v) given wave height (h) seem to be
025 % a reasonable model.
026 %
027 %  DATA: GFAKS89.DAT 
028 % ~~~~~~~~~~~~~~~~~~~
029 % The wave data considered was measured 24th December 1989 at the Gullfaks C platform  
030 % in the North Sea from 17.00 to 21.20. The period from 20.00 to 20.20
031 % is missing and contains NaNs.  The  water depth of  218 m is  
032 % regarded as deep water for the most  important wave components.
033 % There are two EMI laser sensors named 219 and 220. This data set is 
034 % obtained from sensor 219, which is  located in the Northwest
035 % corner  approximately two platform leg diameters away from   
036 % the closest leg.  
037 %   Thus the wave elevation is not expected  to be significantly 
038 % affected by  diffraction effects for incoming waves in the western sector.   
039 % The wind direction for this period is from the south.
040 % Some  difficulties in calibration of the instruments have been reported
041 % resulting in several consecutive measured values being equal or nearly equal 
042 % in the observed data set.
043 %  
044 % Hm0 = 6.8m, Tm02 = 8s, Tp = 10.5 Tp2=19
045 %
046 % Wind data from Statfjord A, 1989 are also given to justify the
047 % assumption that the data may be regarded as stationary.
048 
049 
050 
051 
052 % By pab 28.01.2000
053 
054 %more on
055 help recintro
056 %more off
057

Mathematical Statistics
Centre for Mathematical Sciences
Lund University with Lund Institute of Technology

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