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KEY LARGO. FLORIDA 



UPWELLING SPECTRAL IRRADIANCE AT SURFACE 

 RUN 2 AUGUST 13. 1982 CLEAR SKY 

 MER-1015 SPECTR0RA0I0METER 



4 



30 



109 



160 



MSS 



4. 10 



4. 97 



13. 39 



3. 46 



Habitat 



Sea grass bed 

 Sea grass bed 

 Corals/sand 

 Gulf Stream 



MER simulated MSS 1/2 ratio 



surface irradiance (PAR) = 1. 39-1. 41 x 10 17 Q/cm 2 /s 



_1 L 



400 



500 600 



Wavelength (nm. ) 



700 



Figure 4.--Upwel 1 i ng spectral irradiances taken just beneath the sea surface 

 over a variety of coral reef environments and the western edge of the Gulf 

 Stream. The Mer simulated MSS ratio is the ratio of Band 1/Band 2 of Landsat, 

 calculated from measurements taken with the Mer-1015 Biospherical Instruments 

 spectroradiometer and wavelength weighting functions as described in the text. 



Band 2 (red) = (.036x589nm + .927x625nm + 

 + .810x694nm) / 3.633 



,960x656nm + .90x671nm 



We then calculated the ratio of the bands (Band 1/Band 2) to allow for 

 differences in absolute intensity between the ground and spacecraft signals. 



196 



