Index to data logger channels.

   Date			 Ch1	 Ch2	 Ch3	 Ch4
Fixed format files...
2000 March 4th.		23.4kHz	  -	  -
2000 March 11th		23.4kHz	  -	JJM
2000 June 2nd.		23.4kHz	16kHz	JJM
2000 October 30th	18.3kHz	23.4kHz	JJM
2001 October 14th.	21.7kHz	23.4kHz	JJM
Variable format files...
2001 October 22nd.	21.7kHz 23.4kHz JJM
2001 November 25th.	20.9kHz	23.4kHz	JJM
2002 June 23rd.		AMR	23.4kHz	JJM
2002 July 2nd		20.9kHz	23.4kHz	JJM
2003 April 23rd.	20.9kHz	23.4kHz	JJM	AMR
2003 May 2nd.		20.9kHz	23.4kHz	JJM
2004 April 10th.	20.9kHz	23.4kHz	AMR

JJM = JamJar magnetometer.
AMR = Anisotropic magneto-resistive magnetometer.

John Cook 2005 July 9th.