(band numbers fixed by NASA) and for the conventional photography used in 

 this study are presented in Table 1. Optical filters were used in the 

 conventional photography to match the spectral bands of the MSS. Of par- 

 ticular importance in this study is the water penetration capability of 

 MSS imagery. Because light attenuation by water is related to light 

 wavelength, each spectral band provides a different degree of water pene- 

 tration. Table 2 shows total light attenuation coefficients in clear 

 water for wavelength of peak sensitivity of each MSS spectral band 

 (Polcyn and Rollin, 1969). Thus for clear water, penetration increases 

 as band numbers decrease. 



Table 1. ERTS-1 multispectral scanner 



and aerial photography spectral 

 relationships. 



Sensor 



Wavelength range 

 (micrometers) 





ERTS Band 





4 





0.5 



to 0.6 



5 





0.6 



to 0.7 



6 





0.7 



to 0.8 



7 





0.8 



to 1.1 



NASA Ames Research Center Camera 



1 



0.475 to 0.575 



2 



0.58 to 0.68 



3 



0.69 to 0.76 



4 



0.51 to 0.70 



5 



0.51 to 0.90^ 



Color infrared film roughly compa- 

 rable to a composite photo of MSS 

 bands 4 , 5 , and 7 . 



Table 2. Light attenuation coefficients in clear water. 



MSS Band 



Wavelength of peak sensitivity 

 (micrometers) 



Attenuation coefficient 

 (per meter) 



0.54 

 0.64 

 0.73 

 0.82 



0.04 

 0.20 

 1.00 

 2.00 



10 



