(ZZZZZZZZ 



///// 



H 2 AND DYE PUMPS 

 BUBBLE FILTERS 

 HEAI EXCHANGER 



Figure 9.- ALOPE system with four-wavelength laser head 

 (only one laser wavelength is emitted at a time), 

 25 . 4-cm-diameter receiving telescope, and associated 

 equipment. (Adapted from ref. 13-) 



t 4 



a. 



ol 



■>. 

 .c 



Q. 

 O 



w 



o 



£ 



o 



I830 I900 I930 2000 2030 2100 2130 2200 

 Time 

 9 July 1973 



Figure 10.- Chlorophyll a in vivo concentrations 

 obtained by ALOPE system from George P. Coleman 

 Bridge, which is 30 m above York River. Blue 

 (454 nm) and green (539 nm) wavelengths only 

 were used in data reduction. (From ref. 8.) 



36 



