APPEND U C 



AUTOMATED DATA REDUCTION OF REFLECTION COEFFICIENT 



The steps in the automated data reduction of reflection coefficients 

 using programs WHTCN and WVHTC2 are given below. The programs are 

 described in Section V. 



1. Digitizing . 



The data on the wave records are digitized by CERDP, producing sets 

 of X and y points for each crest, trough, and event mark on each envelope. 

 These points are recorded on tape and then punched on cards. 



2. WVHTCN Program . 



The WVHTCN input for each envelope consists of three sections of 

 cards: crests, troughs, and event marks. Each section begins with a 

 card containing the test label in columns 1 to 15 and ends with a card 

 containing 80 periods. At the front of the envelope data deck is a card 

 with the envelope identification number in columns 21 to 35. Any number 

 of wave envelopes may be run at one time. If an end-of-file is to be 

 written on the tape, the last card of the data deck must have "ENDEND" 

 starting in column 21. Output for each envelope includes a printout of 

 the data for editing, a plot, and a tape for input to WVHTC2. 



3. Estimating Amplitude and Phase Angle of Sine Curve . 



Before running WHTC2, a first estimate of the amplitude and phase 

 angle for the best fit sine curve is determined from the WVHTCN plots. 

 A sine curve with the appropriate wavelength is drawn and placed over 

 the WVHTCN plot. The sine curve is adjusted until it fits the plotted 

 curve most closely. Then the points on the plotted curve coinciding with 

 the crests and troughs of the sine curve are measured and averaged to 

 determine the first estimate of the amplitude. The first estimate of the 

 phase angle (between -180° and +180°) is found by measuring from the 

 origin of the graph to the nearest point where the sine curve crosses the 

 positive or negative x-axis. This value divided by one-half the wavelength 

 of the sine curve and multiplied by tt gives the phase angle in radians. 



4. WVHTC2 Program . 



When running program VA/HTC2, Al = amplitude (F5.2, col. 16); A2 = wave 

 number (2/L), (F5.2, col. 21); A3 = phase angle (F5.2, col. 26); and 

 XXX = the part of the envelope to be plotted C2F5.2, cols. 36 and 41). 

 The limits of the envelope to be fitted are given in inches with a scale 

 of 1 inch equals 5 feet. Time (F5.1, col. 31) is in hours and tenths of 

 an hour. All variables are right- justified when punched into the card. 

 The roll code number is punched in columns 1 to 11 and the envelope num- 

 ber is punched in column 13. One card is punched with this information 



66 



