[time-nuts] Leap second summary, 4 receivers
Bob Adams
badams at mninter.net
Tue Jan 10 22:54:11 EST 2006
I hope this is not too long a post for the group. It's a summary of four
GPS units at the time
of the leap second: an old Garmin StreetPilotGPS, an old Magellan MAP 330,
a Motorola
Encore UT+ with TAC32 software, and an UltraLink 333.
I, too, videotaped the event, captured clear audio from WWV 10MHz,
and saved several data captures for posterity.
A fun evening! Let's all do what we can to slow the earth's rotation more
quickly.
I want another leap second soon!
( Note: ddmm and dddmm are latitude and longitude of my home. )
**************************************************************************
Garmin StreetPilotGPS - Data transmitted every TWO seconds!
**************************************************************************
$GPGLL,ddmm.546,N,dddmm.141,W,235955,A*3C <-- Odd second.
$GPRMC,235956,A,ddmm.546,N,dddmm.141,W,000.0,,311205,... <-- Even second.
$GPGGA,235956,ddmm.546,N,dddmm.141,W,... <-- Even second.
...
$GPGLL,ddmm.546,N,dddmm.141,W,235957,A*3E <-- Odd second.
$GPRMC,235958,A,ddmm.546,N,dddmm.141,W,000.0,,311205,... <-- Even second.
$GPGGA,235958,ddmm.546,N,dddmm.141,W,... <-- Even second.
...
$GPGLL,ddmm.546,N,dddmm.141,W,235959,A*30 <-- Odd second.
<-- LEAP SECOND HERE?
$GPRMC,235959,A,ddmm.546,N,dddmm.141,W,000.0,,311205,...<--Odd second.
$GPGGA,235959,ddmm.546,N,dddmm.141,W,... <--Odd second.
...
$GPGLL,ddmm.546,N,dddmm.141,W,000000,A*31 <-- Even second. <-- ODD/EVEN
ORDER FLIPS.
$GPRMC,000001,A,ddmm.546,N,dddmm.141,W,000.0,,010106,...<-- Odd second.
$GPGGA,000001,ddmm.546,N,dddmm.141,W,... <-- Odd second.
...
$GPGLL,ddmm.546,N,dddmm.141,W,000002,A*33 <-- Even second.
$GPRMC,000003,A,ddmm.546,N,dddmm.141,W,000.0,,010106,...<-- Odd second.
$GPGGA,000003,ddmm.546,N,dddmm.141,W,... <-- Odd second.
...
$GPGLL,ddmm.545,N,dddmm.141,W,000004,A*36 <-- Even second.
$GPRMC,000005,A,ddmm.545,N,dddmm.141,W,000.0,,010106,...<-- Odd second.
$GPGGA,000005,ddmm.545,N,dddmm.141,W,... <-- Odd second.
*************************************************************
Magellan MAP 330 - Data transmitted every second
*************************************************************
$GPGLL,ddmm.5434,N,dddmm.1412,W,235957.981,A*23
$GPGGA,235957.98,ddmm.5434,N,dddmm.1412,W,...
$GPRMC,235957.98,A,ddmm.5434,N,dddmm.1412,W,00.0,000.0,311205,...
...
$GPGLL,ddmm.5434,N,dddmm.1412,W,235958.977,A*25
$GPGGA,235958.98,ddmm.5434,N,dddmm.1412,W,...
$GPRMC,235958.98,A,ddmm.5434,N,dddmm.1412,W,00.0,000.0,311205,...
...
$GPGLL,ddmm.5434,N,dddmm.1412,W,235959.973,A*20
$GPGGA,235959.97,ddmm.5434,N,dddmm.1412,W,...
$GPRMC,235959.97,A,ddmm.5434,N,dddmm.1412,W,00.0,000.0,311205,...
...
$GPGLL,ddmm.5434,N,dddmm.1412,W,000000.969,A*2A --> No real indication
$GPGGA,000000.97,ddmm.5434,N,dddmm.1412,W,... that MAP 330 notices
$GPRMC,000000.97,A,ddmm.5434,N,dddmm.1412,W,00.0,000.0,010106,...
anything going on.
...
$GPGLL,ddmm.5434,N,dddmm.1412,W,000001.977,A*24
$GPGGA,000001.98,ddmm.5434,N,dddmm.1412,W,...
$GPRMC,000001.98,A,ddmm.5434,N,dddmm.1412,W,00.0,000.0,010106,...
...
$GPGLL,ddmm.5434,N,dddmm.1412,W,000002.973,A*23
$GPGGA,000002.97,ddmm.5434,N,dddmm.1412,W,...
$GPRMC,000002.97,A,ddmm.5434,N,dddmm.1412,W,00.0,000.0,010106,...
...
$GPGLL,ddmm.5434,N,dddmm.1412,W,000003.969,A*29
$GPGGA,000003.97,ddmm.5434,N,dddmm.1412,W,...
$GPRMC,000003.97,A,ddmm.5434,N,dddmm.1412,W,00.0,000.0,010106,...
...
$GPGLL,ddmm.5434,N,dddmm.1412,W,000004.977,A*21
$GPGGA,000004.98,ddmm.5434,N,dddmm.1412,W,...
$GPRMC,000004.98,A,ddmm.5434,N,dddmm.1412,W,00.0,000.0,010106,...
...
$GPGLL,ddmm.5434,N,dddmm.1412,W,000005.973,A*24
$GPGGA,000005.97,ddmm.5434,N,dddmm.1412,W,...
$GPRMC,000005.97,A,xxxx.5434,N,dddmm.1412,W,00.0,000.0,010106,....
...
$GPGLL,ddmm.5434,N,dddmm.1412,W,000006.969,A*2C
$GPGGA,000006.97,ddmm.5434,N,dddmm.1412,W,...
$GPRMC,000006.97,A,ddmm.5434,N,dddmm.1412,W,00.0,000.0,010106,...
...
$GPGLL,ddmm.5434,N,dddmm.1412,W,000007.977,A*22
$GPGGA,000007.98,ddmm.5434,N,dddmm.1412,W,...
$GPRMC,000007.98,A,ddmm.5434,N,dddmm.1412,W,00.0,000.0,010106,...
... <-- MAP 330 notices something;
$GPGLL,ddmm.5434,N,dddmm.1412,W,000009.970,A*2B skips second
number 8.
$GPGGA,000009.97,ddmm.5434,N,dddmm.1412,W,... I don't really
understand why.
$GPRMC,000009.97,A,ddmm.5434,N,dddmm.1412,W,00.0,000.0,010106,...
...
$GPGLL,ddmm.5434,N,dddmm.1412,W,000010.978,A*2B
$GPGGA,000010.98,ddmm.5434,N,dddmm.1412,W,...
$GPRMC,000010.98,A,ddmm.5434,N,dddmm.1412,W,00.0,000.0,010106,...
*******************************************************************************************
TAC32 Software and Motorola Oncore UT+ - Data transmitted every second
*******************************************************************************************
Before and After: Receiver responses to
commands @@Ea @@Gj @@Bj @@Bo
-> @@Ea,12,31,2005,23,59,56.000989135,...
-> @@Ea,12,31,2005,23,59,57.000040931,...
-> @@Ea,12,31,2005,23,59,58.000092777,...
-> @@Ea,12,31,2005,23,59,59.000144624,...
-> @@Ea,12,31,2005,23,59,60.000196471,... <-- Leap Second here. TAC32
software displays zero.
-> @@Ea,1,1,2006,0,0,0.000248318,... <-- TAC32 software
displays one.
-> @@Ea,1,1,2006,0,0,1.000300165,... <-- TAC32 software
displays one again.
-> @@Ea,1,1,2006,0,0,2.000352012,... <-- TAC32 software
displays two. Back in sync.
-> @@Ea,1,1,2006,0,0,3.000403859,... <-- All is well.
-> @@Ea,1,1,2006,0,0,4.000455705,... <-- "Time is as it
was." (Star Trek: "City on the Edge of Forever")
--------------------------------------
@@Gj Before event:
-> @@Gj,13,14,2006,1,1,12.999999970,0,0,0
@@Gj After event:
-> @@Gj,13,14,2006,1,1,14.000000000,0,0,0
--------------------------------------
@@Bj Before event:
-> @@Bj +1 leap second is pending
@@Bj After event:
-> @@Bj No leap second pending
-------------------------------------
@@Bo Before event:
-> @@Bo - UTC offset = 13 seconds
@@Bo After event:
-> @@Bo - UTC offset = 14 seconds
*********************************************************************************************
UltraLink 333 (Software version ULM333.D) - Data transmitted every second
*********************************************************************************************
Output from Beagle Software's "ClockWatch Radio Sync" software:
19+? 00 2005 365UTCS 23:59:55I-6
19+? 00 2005 365UTCS 23:59:56I-6
19+? 00 2005 365UTCS 23:59:57I-6
19+? 00 2005 365UTCS 23:59:58I-6
19+? 00 2005 365UTCS 23:59:59I-6
19+? 00 2006 001UTCS 00:00:00I-6 <--Leap Second here. No sign of it.
19+? 00 2006 001UTCS 00:00:01I-6 Poor signal. Wasn't really
receiving any data.
19+? 00 2006 001UTCS 00:00:02I-6
19+? 00 2006 001UTCS 00:00:03I-6
19+? 00 2006 001UTCS 00:00:04I-6
19+? 00 2006 001UTCS 00:00:05I-6
[Snip]
59+0C01 2006 001UTCS 01:16:29I-6 <--Stronger signal, now shows unit
re-syncing.
59+0C01 2006 001UTCS 01:16:30I-6
59+0C01 2006 001UTCS 01:16:31I-6
59+0C00·2006 001UTCS 01:16:32 + 3 <-- Re-sync with WWVB signal.
59+0C00·2006 001UTCS 01:16:33 + 3
59+0C00·2006 001UTCS 01:16:34 + 3 After re-sync, note space after plus sign.
59+1C00·2006 001UTCS 01:16:35 + 3 Causes the numeral 3 to be "off the
screen" on the UltraLink 333 display.
It will show a numeral again when UT1-UTC returns to zero.
At least that's what it did in 2001.
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