was known by the power setting of the plane throttles, one simple subtraction yielded 

 the effective wind speed. Due to the directions of the wind and of the plane flight, 

 this effective wind speed was practically identical to the true wind speed at the alti- 

 tude of the aircraft, 500 feet above the mean sea surface. The average wind on the 

 downwind run was estimated by taking the total distance out from the coast that the 

 plane travelled and dividing by the total time required to transverse this distance. 

 The result was a 33 knot (17.0m/sec) wind. Similarly, on the upwind leg the aver- 

 age wind was 30 knots (115.4 m/sec). it should be expected that these values will be 

 a bit lower than the actual wind speed, since the plane did not fly a precisely straight 

 line out from the coast. 



To obtain an estimate of the uniformity of the wind field with distance from 

 the coast, values of wind speed were calculated using successive five minute positions^ 

 The smoothed results are shown in Table 2. These data should be viewed with caution 

 due to the relative inaccuracy of the smoothed LORAN A positions. The "downwind 

 wind speeds" show a fairly large variability, but this was to be expected, since the 

 plane's ground speed of approximately 220 knots will give rise to a larger positioning 

 error. The "upwind wind speeds" are more uniform as the approximate ground speed 

 here was 150 knots. Even after the problems and inaccuracies involved in plane 

 positioning are realized, the results of Table 2 are unexpectedly good. This is due 

 in no small part to the very careful and diligent efforts of the navigator and crew of 

 the aircraft. A straight linear average shows a characteristic wind of 38.0 knots 

 (19.5 m/sec) on the downwind leg ond 34 = 7 knots (17„9 m/sec) on the upwind leg, 

 both of which are somewhat higher than the total run estimates. Considering the 

 altitude of the plane and the atmospheric stability, these wind estimates are in good 

 accord with the lightship data. They further show that, at least in a relative way, 

 the wind field was uniform with respect to distance from the coast. No attempt was 

 made to reduce the plane winds to equivalent 10 meter winds. 



The weather situation may be summarized by saying that the waves measured 

 were generated by a steady, nearly offshore wind of speed 30-35 knots (15.4-18.0 

 m/sec) and direction 335"'T which had been blowing for at least 12 hours but probably 

 nearer to 16 hours. These were the large scale features of the wind field. 



5.0 TREATMENT OF THE DATA 



5.1 Spectral Analysis 



Near continuous records of the sea surface profile from near the coast out 

 to a distance of approximately 190 nm were obtained. Figure 2 is an example. 

 Segments of the altimeter record taken within 50 nm of the coast were digitized at an 

 interval of 0.05 second, while for all other parts of the record, the interval was 



18 



