device which records heights of surface waves; the radar profiler is 

 a high-resolution altimeter that determines height of the sea surface 

 from an aircraft; the scatterometer measures the intensity of a re- 

 flected radar beam. 



Statistical properties of the sea surface vary with time and 

 space. A fixed sensor, such as a wave staff, yields information on 

 the temporal variability of the sea surface at one point. Both air- 

 craft systems, however, move so rapidly over the sea surface that 

 they yield information with spatial variability that is essentially 

 free of time changes. 



For this experiment, the wave staff at ARGUS tower operated con- 

 tinuously while the other recorders were flown in a crisscross pattern 

 above the tower. The result was a star-shaped flight track, the cen- 

 ter of which was located over the tower. 



A curve of scattering versus depression angle was plotted for all 

 legs of the scatterometer track. Wave power spectra (frequency versus 

 variance) were computed along the radar wave profiler track and for 

 the wave staff on ARGUS. These space and time spectra were then com- 

 pared to the scatterometer reflectivity curves. Figure 17 is an exam- 

 ple of a scatterometer reflectivity plot. 















REFL 



ECTIVITY PLOT 















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THET 



< DEGREES 



START 10 26 20,000 

 STOP 10 26 20,000 

 * AVERAGE 

 AVERAGE + STO DEV 



NATIONAL AERONAUTICS AND SPA 

 MANNED SPACECRAFT CENTER - 

 SCATTEROMETER MISSION 20 



FLIGHT 2 LINE I 



RUN I SITE 86 



: ADMINISTRATION 



AVERAGE - STD DEV TAPES 



90S6 



FORE SCATTER 



Figure 17 Example of a Scatterometer Reflectivity Plot 



29 



