VI. FUTURE WORK. 
Regarding future work there are several levels at which it is 
intended to extend technique and data analysis. Firstly it would 
be interesting to take the stereo images at different coverages, 
through varying the camera to water height. This would both 
allow the exploration of spatial statistics at different wave 
scales and also extend the range of the automated wavenumber 
spectra both up to higher wavenumbers, well into the capillary 
range and to lower wavenumbers up to and beyond the spectral 
peak. 
Secondly the use of shape from shading as an alternative means 
of deriving automated sea surface elevation would provide an 
interesting complimentary technique to stereo-matching, with 
the possibility of a higher spectral resolution (Frankot and 
Chellappa, 1988). Work on this is being undertaken. It is 
hoped to have a direct spatial and spectral comparison of results 
from the two techniques using the same images in the near 
future. This together with spot height measurements on an 
analytical plotter will provide an extensive analysis of the 
field. 
Thirdly, though wave staffs have the limitations outlined in 
section I , they never the less represent one of the most 
important ways of cross validating wave spectra derived using 
the automated imaging techniques. Therefore it would be 
interesting to both extend the point wave staff spectra to higher 
wavenumbers and obtain directional wave staff spectra, allow a 
direct comparison of directional spectra. Measurements are 
currently being made with an array of seven wave staffs rather 
than the single staff which will provide directional information, 
though these only still resolve up to 3Hz. To resolve higher 
wavenumbers up to 8Hz we will be collaborating in the near fu- 
ture with a group in Venice who are using a novel wave probe 
based on an X-band microwave probe (Fiscella et al., 1982, 
1991). Such an inter-comparison will provide a unique 
opportunity for investigating the resolution and, strengths and 
weakness of these different approaches at the high frequency end 
of the spectrum. Finally, these results open the possibility for 
investigating a whole range of non-guassian spatial statistics, 
and their relationship to microwave returns, not possible in 
such detail until now (Longuet-Higgins, 1983; Srokosz, 1986). 
It is intended to extend the data analysis to explore these 
aspects of the results. 
The viability of the automated stereo-matching of water images 
to derive short gravity-capillary wave height distributions and 
directional high wavenumber power spectra has been proved. 
Consistency has been shown between the wave staff spectra and 
automated wave height measurements and in the linearity of the 
resulting wave number spectra with another author. It is hoped 
that such a technique will soon make possible the rapid 
automated processing of the large quantities of data generated in 
the oceanographic study of wind-generated waves and permit the 
long-term development of microwave inversion techniques for 
geophysical parameter extraction from spaceborne 
measurements. 
Acknowledgements. 
The authors thank Dr C. Clayson, Mr M. Hartman & Mr M. 
Conquer of the Institute of Oceanographic Science Deacon 
Laboratory, Wormley, UK, for their significant contribution in 
the data acquisition process and Ms H. Marshall of UCL for her 
assistance in the photogrammetric restitution process on the 
analytical plotter. This research is funded by the Natural 
Environment Research Council under case studentship. 
    
   
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
   
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
   
  
   
  
   
   
   
   
     
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