depending on the physical characteristics of seawater. Although this 

 penetration capability may be inadequate for deeper areas, it has proven 

 useful for making qualitative observations of estuarine and nearshore 

 underwater features . 



The other important characteristic is the image resolution capable of 

 discerning small-scale features normally required in coastal studies, 

 i.e., wave patterns, nearshore current patterns, morphological features 

 on beaches, and engineering structures such as groins, seawalls, jetties, 

 and breakwaters. At present, such features must be sufficiently large 

 to fall within the limits of the ERTS-1 sensor's resolving capability. 

 Examination of the ERTS-1 imagery has shown that, although some smaller 

 scale features of interest in coastal engineering are not visible in the 

 imagery, many important observations of gross features can be made. Most 

 notable were the temporal changes in morphology of tidal inlets and 

 barrier islands observed by comparing the ERTS-1 images. In addition, 

 the current resolving capability of the multispectral scanner appears to 

 be adequate for mapping land-water interfaces with a degree of accuracy 

 that compares favorably with current methods of mapping. 



IX. RECOMMENDATIONS 



For coastal engineering, improvements in depth penetration capability 

 and resolving power would probably lead to wider application of satellite 

 imagery in coastal studies. While the ERTS-1 imagery has proven useful 

 in analyzing gross surface and nearshore features, much of what needs to 

 be examined in the solution of coastal engineering problems is found 

 below water level and at scales too small for or bordering on the present 

 resolving capability of the multispectral scanner. A resolving power of 

 50 feet or better would adequately cover most structures and features of 

 interest in coastal engineering. It is anticipated that improvements in 

 optical technology to be incorporated in future satellites will include 

 increased resolving capability. Greater water penetration capability may 

 be afforded by the addition of a blue-band channel in future satellite- 

 borne sensors. 



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