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363000 1364000 1 365000 1366000 1367000 136800 







Figure 44. Digitally collected hydrographic data from a Florida project site. The track lines 

 are obvious, as is the fact that the soundings are not uniformly distributed 

 throughout the survey area. (Data courtesy of USAE District, Mobile) 



comparing a gridded surface with a hand-contoured chart, how can a 

 researcher really state that one surface does not look right while another does? 



The fundamental challenge of a gridding algorithm is to estimate depth 

 values in regions of sparse data. The procedure must attempt to create a 

 surface that follows the trend of the terrain as demonstrated in the areas where 

 data do exist. In effect, this is similar to the trend-estimating that a human 

 performs when he contours bathymetric data by hand. The other challenge 

 occurs in complex, densely sampled terrains. The algorithm must fit the 

 surface over many points, but genuine topographic relief must not be 



112 



Chapter 5 Analysis and Interpretation of Coastal Data 



