[daip] Re: CLCOR position shifts (fwd)

[Leonia Kogan]

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>From brunthal at mpifr-bonn.mpg.de Tue Sep 10 04:26 MDT 2002
Date: Tue, 10 Sep 2002 12:26:55 +0200
From: Andreas Brunthaler <brunthal at mpifr-bonn.mpg.de>
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To: Leonia Kogan <lkogan at zia.aoc.NRAO.EDU>
Subject: Re: [daip] Re: CLCOR position shifts (fwd)
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Leonia,

I tried it today and it works now. Thank you for the help.

Best Regards,
Andreas

Leonia Kogan wrote:
> Andreas,
> 
> You have been right. There has been a problem, and I found it.
> 
> Both FITLD and CLCOR use the subroutine JPRECS to convert epoch coordinates
> to apparent coordinates (in FITLD) and back in CLCOR.
> 
> I ran CLCOR with CLCORPRM =1.0e-8. This value is small enough to consider 
> that recalculation of the coordinates has to return back to the original 
> epoch coordinates. But I found that CLCOR gives a small difference 
> with the original epoch coordinates.
> 
> I found the reason:
> 
> JPRECS has one of the input parameters:
> GR: If true correct apparent position for the general
>     relativistic bending of light by the sun.
> 
> Of cource GR has to be identical in FITLD and CLCOR, but it is not true:
> 
> FITLD:   GR=.FALSE.
> CLCOR:   GR=.TRUE.
> 
> I'll fix it on Monday.
> 
> Thank you for pointing out to the problem
> 
> Leonia
> 




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