From: Walt Stafford <STAFFORD@BBRI.ERI.HARVARD.EDU>
  To  : rasmb@BBRI.ERI.HARVARD.EDU
  Date: Sat, 24 Jun 1995 11:46:48 -0400 (EDT)

w^2t

Hi-
	My program dc_dt uses the value of w^2t stored in the second line 
of the XL-A output file. To get values of t(sed), I compute them from 

	t(sed) = (w^2t)/(w^2)

using the value of rpm also stored on the second line. In the header of the 
output file from dc_dt, I list the value of w^2t and t(sed) for the 
resulting g(s*) pattern. I compute t(sed) from the harmonic mean of the 
times of all the patterns used to compute the final pattern. The value of 
w^2t listed is computed by taking that value of t(sed) (i.e. the harmonic 
mean value) and multiplying by w^2 corresponding to the speed at which the 
scans were obtained. I have not had any problems as long at I used the 
value of the integral of w^2dt stored on the second line.

	I have checked the value of w^2t that is displayed on the console 
in the w^2t mode against the one I obtain independently (by counting pulses 
from the rotor) for my Rayleigh system and they are the same. 
 
The time displayed on the second line is the elapsed time from the 
beginning of the run, and should be ignored.

-Walt Stafford