RE: No Escape

[Tom Droege <tdroege@veriomail.com>]

Chris and all,

OK, but I have the specific problem of doing it.  On a particular computer 
and with a particular code.

We are using CFITSIO to write the headers.  Now I have to put specific 
things in the headers.  It does me no good that this is done at every other 
observatory in the universe.  It seems that I have to do it.  In 
particular, I have to do some computations to get the pointing 
approximately right so later processing stages can match the image to a 
catalog.

Possibly CFITSIO will compute the RA where the telescope is pointing if I 
give it local time, longitude, and zenith angle.  What say, CFITSIO 
experts?  Otherwise it seems that I will have to do it.

I have a similar problem with time.  I will use my eyeball and a gps 
receiver to set the Windows clock.  If one of you programmers were here, 
you could get my network going and get time over the network from the 
computer that is connected to the internet.  Then you could write whatever 
is necessary to link to the internet and update the Windows clock so that 
it is right.  But I can't do that.  I can do other things, some of them 
even useful.  I could even do that kind of software, but it would take a 
while to get up to speed.

Mostly I now understand what I have to do and have most of what I need to 
do it.  I do seem to have to compute RA of the zenith at my location.  I 
have several tools to do this now.  I do need the correct time.  I will use 
the manual input of the gps number to get the Windows clock  right.  Rob 
has done the rest.

Tom Droege


At 01:41 PM 3/13/01 -0800, you wrote:

>Along that same line, Software to do everything that has been discussed
>on this list over that last few days is all available for free.  There
>is really no need to write you own FITS headers, write routines to
>do "date-time arithmetic" or spherical trig.  This stuff was done years
>ago.