| Subject: RE: RADAR 
      INVISIBILITY - SLIDE 84 - "FER DE LANCE" INDEX  Date: Fri, 19 Apr 2002 17:35:16 -0500 
        
        Dear Suzanne, 
        
          
        
        The black shadow once 
        the object "disappears" from visual detection would be  because the 
        cancellation process is not quite perfect in the real world.  So by 
        using cancellation signals added to all reflection signals, and adding 
        the slightly delayed transmission of what would be seen from the other 
        side, some deviations occur.  Also, the input signal to be canceled will 
        "speckle" and oscillate randomly in brightness etc.   These are random, 
        due to both some random error in direction correlation and also in some 
        random errors in exact frequency spectrum duplication, as well as slight 
        random error in magnitudes of processed signals, and the random 
        "speckle" of the signal one works on.   The end result is that a 
        "residue" of random very weak signals remain.  They cover the whole 
        visible spectrum and beyond, and contain a complete spectrum of 
        "cancellation" errors.  To get rid of the "sparkle" and "speckle" that 
        would result, one would have to adjust the cancellation gain up a bit.  
        The excess error signals tend to be mostly cancellation errors, so 
        result in the appearance of "black" rather than light.  This would have 
        to be all across the spectrum, since the excess "speckle" or "sparkle" 
        errors are all across it.  In simple terms, there has to be just a wee 
        bit too much cancellation, which is required, otherwise flashes and 
        speckles would get through. 
        
          
        
        So one would see a 
        sort of "black shadow", which is a decisive signature. 
        
          
        
          
        
        Cheers, 
        
        Tom Bearden 
        
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