From: "Andrew Clerkin" <aclerkin
To: suhovecky
Date: Fri, 28 Apr 2006 10:26:33 -0400
	FILETIME=[C22D48C0:01C66ACF]

Mark,

Some observers detect a given SID as an increase in signal while others will 
detect the same event as a decrease in signal. For instance, I recorded 
yesterday's large event as an increase in signal. The reason appears to be 
due to constructive and destructive interference of the sky wave and ground 
wave arriving at the observer's receiver. Each observer has their own unique 
propagation path from the transmitter to the receiver. The length of a given 
propagation path will change as the height and density of the ionosphere 
changes when hit by xrays from a solar flare or other source (i.e. GRB). If 
the ground wave and the sky waves arrive at the reciver in phase then there 
will be constructive interference and the event would appear as increase in 
signal. If the waves arrive at the receiver out of phase then the event 
would appear as a decrease in signal. Many times the signal will start in 
one direction and part way through the event, the signal will reverse 
direction. This would be consistent with the changing height of the 
ionosphere as an event progresses. Your signal waves may be in phase as the 
event starts, but go out of phase as the length of the propagation path 
changes during the course of the event.



>From: the suhoveckys <suhovecky
>Date: Fri, 28 Apr 2006 05:08:28 -0400
>
>
>
>Excuse a question from a relatively inexperienced observer.
>
>
>http://www.suhovecky.net/siddata/sid060427.gif
>
>Up until now, the SIDs I've detected were all increases in signal. This 
>one, however, is
>marked by a big drop in signal. Can anyone on the list explain what the 
>deal is here?
>
>Thanks for any enlightenment,
>
>Mark Suhovecky
>A115
>suhovecky
>
>
>
>_______________________________________________