From: John Labrecque
Author: Kurt Feigl, Toulouse
Date: 18 Mar 1995 19:43:26 
Subject: [SCIGN-0056] Re

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SCIGN Electronic Mail    Sat Mar 18 19:43:26 PST 1995      Message Number 0056
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Author: John Labrecque
Subject: Re: No 51: blind test

Excellent suggestion. Sort of like a GPS easter egg hunt. Which antenna was 
moved? john


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Subject: No 51: blind test

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SCIGN Electronic Mail    Fri Mar  3  0:01:39 PST 1995      Message Number 0051
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Author: Kurt Feigl, Toulouse
Subject: blind test

In response to Keith Stark's message:

> On February 23rd, site personnel at UCLA were working with the
> monumentation at UCLP which may have inadvertently caused the antenna to be
> displaced as much as a few centimeters.  We aplogize for not getting out a
> message earlier, but we were not notified of this change until this
> morning.

I am distressed that he had to be notified.  This sort of signal should be
detected by the network itself.

I would suggest a *blind test*.  I challenge the various processing
groups to analyse this day's data sequentially to determine *when* the
movement occurred, and its magnitude.  If GPS is going to be useful
for ultra-long period seismology on scales of hours, it will have to
break the habit of one solution per day....

Playing the devil's advocate,

Kurt

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*  Kurt Feigl                     Observatoire Midi Pyrenees *   
*  office: (33) 61 33 29 40       14, Ave. Edouard Belin     *  
*  fax     (33) 61 25 32 05       31400 TOULOUSE             * 
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[Mailed From: Kurt FEIGL <feigl@medoc.cnes.fr>]


[Mailed From: Robert Liu <robliu@igscb.jpl.nasa.gov>]
