the output obtainedby this particular technique. 

 This technique requires 30 minutes to generate 

 a completed presentation. Although the tinne 

 seems long for analyzing only 5 seconds of a 

 tape recording, it was short compared to the 

 time necessary for hand reducing the tape 

 information obtained from USNOTS. The 

 amount of tape that could be analyzed in this 

 fashion was certainly limited, and a quick 

 search method was still needed for locating 

 sections of tape of interest. In the photographs 

 obtained with this technique, certain indicated 

 anomalies were later shown to be produced by 

 the wow and flutter of the tape recorder in 

 both the recording and playback mode. Steps 

 were taken to remove the playback wow and 

 flutter and to. reduce the wow and flutter pro- 

 duced in recording. Careful observation of the 

 figure shows faint sinusoidal curves passing 

 through the noise. These signals appear to 

 correlate with the motion of the yellowtail 

 specimen used in the Mission Bay Yacht Club 

 tests. 



3-D Technique 



The final technique that was used for the 

 production of individual photographs necessary 

 for the construction of a three-dimensional 

 model is shown in block diagram (fig. 10) and 

 indicates the simplicity of the test setup. 



The technique is reasonably good, but, as 

 before, the time required is 15 seconds per 

 picture. Figure 11 shows a sample of one of 

 the photographs produced from the CRT used 

 in this approach. 



The model, composed of 25 individual photo- 

 graphs such as that in figure 11, is shown in 

 figure 12. This model of one film "take" at 

 Catalina contains information on the activity 

 of the fish in the area of the chumming plat- 

 form. The correlation between the activity of 

 fish in the test photographs and the model is 

 reasonable. The density of activity was too 

 great to isolate individual specimens as in the 

 Mission Bay tests, but some individual corre- 

 lations could be seen in the model constructed. 



Figure 10,- -Spectrum-analysis block diagram used for 3-D 

 model. 



LJJ 



D 



3 



< 



N M\n^' 



TIME 



Figure U. — Representative output from narrow-band analysis technique. 



13 



