ABSTRACT 



The Taylor Model Basin Seakeeping Data Analysis Center 

 (SEADAC) is described. The methods for preparation, analysis, 

 and storage of data are outlined. Confidence in the system is 

 demonstrated by comparison of SEADAC computation of the spectral 

 density of certain seakeeping events with numerical calculation 

 of the same data. The limitations of the SEADAC are listed and 

 changes that will improve the system's efficiency and extend 

 its capabilities are suggested. 



INTRODUCTION 



In recent years there has been a trend toward the collection of large 

 amounts of seakeeping data on full-scale trials. Two more sources of 

 exceptionally large data supplies will soon appear at the Taylor Model 

 Basin. The first is a system of automatic seakeeping instrumentation for 

 TMB which will permit unattended quasi-continuous recording of full- 

 scale seakeeping events for months at a time; the second is the new sea- 

 keeping facility (nearing completion) wherein much testing in irregular 

 waves is anticipated. 



Until recently, all detailed analyses of seakeeping data have been 

 carried out by the Applied Mathematics Laboratory, on the UNIVAC I and II, 

 and on the IBM 7D4. On the whole, these services have been satisfactory. 



Certain deficiencies in our earlier methods of data handling became 

 apparent, as the volume of data increased. The most obvious of these 

 was (and still is) the expensive and time-consuming job of data preparation 

 for input to the general purpose digital computer. The original data are 

 displayed on chart paper from which semi-automatic readings are taken at 



