My VLF/LF capture has started to yield information now.
I captured the antennasignal from my home-brew loop antenna
(
http://phk.freebsd.dk/loran-c/Antenna/) with an Adlink 9812
ADC card at 12 bits and 5 million samples per second.
In total I have 400GB of capture, almost 80000 seconds around
the leapsecond.
Some crude software-radio and some CPU hours later, here is the
DCF77 behaviour during the leapsecond:
At midnight, local time the leap warning bit is turned on:
v
24410.639 00000000000000000010111001010110001110001101101001101000001 23:53 0
24470.639 00000000000000000010100101011110001110001101101001101000001 23:54 0
24530.639 00000000000000000010110101010110001110001101101001101000001 23:55 0
24590.638 00000000000000000010101101010110001110001101101001101000001 23:56 0
24650.638 00000000000000000010111101011110001110001101101001101000001 23:57 0
24710.638 00000000000000000010100011011110001110001101101001101000001 23:58 0
24770.639 00000000000000000010110011010110001110001101101001101000001 23:59 0
24830.639 00000000000000000010100000000000000010000011110000011000001 00:00 0
24890.638 00000000000000000011110000001000000010000011110000011000001 00:01 1
24950.638 00000000000000000011101000001000000010000011110000011000001 00:02 1
25010.638 00000000000000000011111000000000000010000011110000011000001 00:03 1
25070.639 00000000000000000011100100001000000010000011110000011000001 00:04 1
25130.639 00000000000000000011110100000000000010000011110000011000001 00:05 1
25190.639 00000000000000000011101100000000000010000011110000011000001 00:06 1
25250.638 00000000000000000011111100001000000010000011110000011000001 00:07 1
And at 00:00 UTC the leapsecond happens and the leap warning bit turns off:
28010.639 00000000000000000011111001010000000010000011110000011000001 00:53 1
28070.639 00000000000000000011100101011000000010000011110000011000001 00:54 1
28130.638 00000000000000000011110101010000000010000011110000011000001 00:55 1
28190.638 00000000000000000011101101010000000010000011110000011000001 00:56 1
28250.638 00000000000000000011111101011000000010000011110000011000001 00:57 1
28310.639 00000000000000000011100011011000000010000011110000011000001 00:58 1
28370.639 00000000000000000011110011010000000010000011110000011000001 00:59 1
28430.638 000000000000000000111000000001000001100000111100000110000010 01:00 1
28491.639 00000000000000000010110000001100000110000011110000011000001 01:01 0
28551.639 00000000000000000010101000001100000110000011110000011000001 01:02 0
28611.638 00000000000000000010111000000100000110000011110000011000001 01:03 0
28671.638 00000000000000000010100100001100000110000011110000011000001 01:04 0
28731.638 00000000000000000010110100000100000110000011110000011000001 01:05 0
28791.639 00000000000000000010101100000100000110000011110000011000001 01:06 0
28851.639 00000000000000000010111100001100000110000011110000011000001 01:07 0
The first column is the number of seconds into the capture data and you
can also see the extra second going from 28430.638 to 28491.639
Rugby and HBG and France Inter will follow in the coming days if I can
get my software to decode them.
--
Poul-Henning Kamp | UNIX since Zilog Zeus 3.20
phk_at_FreeBSD.ORG | TCP/IP since RFC 956
FreeBSD committer | BSD since 4.3-tahoe
Never attribute to malice what can adequately be explained by incompetence.
Received on Fri Jan 06 2006 - 14:47:42 PST