Subject: Re: Corrected gain fitting tables

Dear Soeren,

many thanks for your two cents. I think what you're suggesting could be 
incorporated into the ISDC system somehow, but to have the j_cor_gain make the
smoothed table as an output, would mean that a new file would be added to the
SCW group for each science window. I'll discuss this with the ISDC gurus and
see what we can do.

Best wishes,

Carol Anne


> Subject: Re: Corrected gain fitting tables

> 
> Carol Anne,
> 
> It may be nice that this has a minimum impact on the already
> existing system. However, it does not fix what I consider a serious
> weakness of the existing system: the fact that the existing gain
> history table does NOT say anything about which correction is
> actually applied in the end. Therefore I find it a natural requirement
> that there always exist two tables, the raw gain history table derived
> from the individual calibration spectra PLUS a table from which the
> gain corrections are actually made by linear interpolation.
> The second table may then just be made from the automatic fitting
> algorithm or inserted by hand.
> This would make for a much more transparent and friendly system,
> getting away from the 'blindly-push-the-button-on-the-black-box'
> approach.
> 
> my two cents
> 
> Søren
> 
> 
> > Dear Silvia,
> >
> > I have written a SCREW to allow us to deliver hand-made gain history
> > tables,
> > ones that are already smoothed and just require linear interpolation to
> > get
> > the gain correction done. The SCREW as it appears at ISDC is attached
> > below.
> >
> > Thinking about this problem, it seems that the easiest way to implement it
> > is
> > for the delivered tables from DNSC to be put in the same directory as the
> > `raw' gain history tables, i.e. REP_BASE/scw/RRRR/rev.001/idx, but with a
> > different file name. The format of the two sets of gain history tables
> > would be
> > identical, so no new template needed there. Then it would be up to the
> > scripts
> > to check which filenames are available, and IF there's a delivered gain
> > history
> > table use this. If there isn't a delivered gain history table, the scripts
> > just use the regular `raw' tables used so far. Also if the delivered table
> > is
> > used, the scripts should set the gain smoothing model (gainModel) to 0 for
> > linear interpolation.
> >
> > If all the work is done in the scripts like this, j_cor_gain doesn't need
> > to be
> > changed at all. Actually, it would be very hard for j_cor_gain to go and
> > find
> > an alternative table for itself because the gain history tables are not
> > part of
> > the science window group (being part of the revolution file pipeline), so
> > I
> > think changing the scripts is the only way to get this done easily.
> >
> > Initially, we envisage delivering improved gain history tables for a few
> > revolutions that have had problems with many switches on and off, and
> > others
> > that are very sparse due to heavy gain filtering. However, we could easily
> > generate smoothed tables for every revolution, though in the nrt regime
> > the
> > `raw' gain history tables will still be the default.
> >
> > Please tell me what you think of this idea, and how soon we could get it
> > implemented.
> >
> > Best wishes,
> >
> > Carol Anne
> >
> >
> >
> > DANISH NATIONAL SPACE CENTER
> > Dr. Carol Anne Oxborrow
> > Email: oxborrow@dnsc.dk	Homepage: http://www.dsri.dk/~oxborrow
> > Telephone (direct): +45 35 32 57 33
> > Telephone (secretary): +45 35 32 57 01
> > Fax: +45 35 36 24 75
> >
> > -------------------
> >
> > The Danish National Space Center (DNSC) is a new research center under the
> > Ministry of Science, Technology and Innovation. The center is the result
> > of the Danish Space Research Institute merging with a part of the National
> > Survey and Cadastre.
> >
> > Read more about the Danish National Space Center at: www.spacecenter.dk
> > E-mail: office@spacecenter.dk
> >
> >
> 
> 


DANISH NATIONAL SPACE CENTER
Dr. Carol Anne Oxborrow
Email: oxborrow@dnsc.dk	Homepage: http://www.dsri.dk/~oxborrow
Telephone (direct): +45 35 32 57 33
Telephone (secretary): +45 35 32 57 01
Fax: +45 35 36 24 75

-------------------

The Danish National Space Center (DNSC) is a new research center under the
Ministry of Science, Technology and Innovation. The center is the result
of the Danish Space Research Institute merging with a part of the National
Survey and Cadastre.

Read more about the Danish National Space Center at: www.spacecenter.dk
E-mail: office@spacecenter.dk