It should be obvious by now that the experimental setup for a 

 particular analysis is highly subjective. The results depend on: 



1. Loop time (length of record). 



2. Filter bandwidth. 



3. Scan rate . 



4. Time constant. 



Project engineers are encouraged to familiarize themselves with 

 the operation of the equipment so that, with the cooperation of the 

 SEADAC engineer, the most useful analysis can be made. 



4. DATA STORAGE 



After all the analyses are completed for a particular magnetic 

 tape loop, the loop is stored in a small plastic cylinder and the 

 cylinder is labeled with identification that relates its contents to 

 a particular page in the "book" (Figure 2) wherein is contained all 

 pertinent information on the trial. 



Both the tapes and the book are filed for future reference. 



COMPARISON OF SEADAC ANALYSIS WITH DIGITAL METHODS 

 The SEADAC is concerned primarily with the electronic determination 

 of the spectral density function of a seakeeping event as represented 

 by the observed time-history of that event. In a very general way, 

 the spectral density function may be considered to be a display of the 

 harmonic components contained in a signal such that the amplitude of 

 each component is squared (ordinate) and assigned to its respective 

 frequency (abscissa). 



15 



