On Friday, January 24, 2014 8:43:54 AM UTC-5, haitic...@gmail.com wrote:   
   > On Friday, January 24, 2014 3:26:37 AM UTC-5, Jeroen Belleman wrote:   
   >    
      
   >    
   > Hi Jeroen,   
   >    
   > To be fair, you are correct, the signal IS growing faster than the noise.   
   But what allows Messr. Horowitz to see it is that the 'standard deviation' of   
   the noise goes way down, more than the SD of the signal. So if you do Y   
   measurement episodes of X    
   measures each, the variation in the noise (in the reference beam) will be   
   tight, and the signal (in the measurement beam) will almost always be greater   
   than that tight noise floor.   
   >    
   Weird, what do you mean by the SD of the signal or even of the noise for that   
   matter?   (Hmm OK I guess for random noise the amplitude is Gaussian and that   
   could be used to define some standard deviation of the ampltude    
   istribution... Is that what you    
   mean?)     
   >    
   >    
   > To be frank, I am a software person, and to be put algorithms in code, you   
   have to know exactly how the little gears turn.    
   Grin.. you also need to understand all the "little gears" to do it in hardware   
   too!    
    So one of my favorite tricks is to use a digital 'scope as a poor mans LI.    
   Send the signal into one channel, and (modulation) reference, into the other.    
   Trigger on the reference and average the signal.   You can do the same trick   
   triggering on the AC    
   power line to see the 50/60Hz interference too.       
      
   George H.   
   >    
   >    
   >    
   > JB   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)