It is apparent that the measurements token during this experiment have not 

 been seriously affected by the various motions of the aircraft. Nevertheless, plans 

 are being made to record the rotational motions of the aircraft in all subsequent 

 work. 



3o3 Navigation 



Navigation of the aircraft was accomplished with LORAN A, After an 

 initial positioning over the TACAN Station at bea Isle, New Jersey, lines of position 

 were determined from LORAN rates 1 H4 and 1 H5. Estimates of positioning error are 

 shown in Figure 6 which contains accuracy contours for these two rates at the 95% 

 confidence level » It is clear that estimates of positioning can be approximated no 

 more accurately than ±0.5 nautical mile at the 95% level. This estimate of 

 accuracy is based on the assumption that other contributing factors such as operator 

 error and instrument calibration error (for both airborne and ground equipment) were 

 negligible. While the assumption of negligible instrument error is reasonably sound, 

 the same may not always be said for operator error which depends, among other things, 

 on operator skill and quality of the LORAN signal. Errors in heading are related to 

 errors in lines of position since individual changes in heading were based on each of 

 the points of position. It appears that estimates of plane heading may be considered 

 accurate to within 5°. 



4.0 THE WEATHER SITUATION 



4.1 The General Weather Picture 



In order to attempt significant estimates of the evolution of wave spectrum. 

 It was essential, as previously noted, that the measurements be made under "ideal" 

 wind conditions. Ideal, in this case, meant that an offshore wind of constant 

 velocity should have been blowing over a large area of ocean for a time t (Section 

 2.0) prior to wove observation. Further, it was required that the wind field should 

 have been uniform in its lateral extent. These were rigorous conditions to try to meet, 

 but quite fortunately the wind field over and around the area of measurement was 

 about as geophysicolly constant as could be hoped. 



The general weather situation was as follows*: Early on 17 February a weak 

 low pressure system (1007 mb) located just north of the North Dakota-Canadian border 

 began to develop further in its eastward movement. A high pressure system of moderate 

 strength pushing ESE out of Canada was beginning to accelerate the eastward movement 

 of the cyclone. At OOOOZ on 18 February, the now massive cyclone center (lOOOmb) 

 was located midway between James Bay and the Great Lakes. 



*We are grateful to Mr. Lionel I. Moskowitz for providing the general weather 

 analysis. 



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