446 



TYLER AND PREISENDORFER 



10. Path Function 



[chap. 8 



No instrument has been developed for the measurement of the path function 

 under water. 



11. Data 



Values of the reflectance function, Rao, the distribution function, D{ — ) and 

 D{ + ), the diffuse attenuation function, K{ — ), and the absorption coefficient, a, 

 computed for various depths from Tyler's (1960) radiance distribution data, 

 are given in Table XIV. The peak wavelength for this data is 480 y. and the 

 half-band width 64 [i. 



Table XIV 



12. Applications 



At the present time there appear to be three broad areas of application for 

 light measurements in the ocean. These can be classified under the headings : 



A. Descriptive oceanography and other geophysical applications. 



B. Photosynthesis and other biological phenomena. 



C. Image-recording equipment. 



A. Descriptive Oceanography and Other Geophysical Applications 



The fact that certain geophysical features of the ocean are associated with 

 characteristic optical properties has led to the use of optical measurements as 

 a means for locating and describing these features. 



