Yes, the fits headers would provide a path back to the original
processing. The only other questions are: (i) does the fits
header contain the version # of Elixir that was used? (I believe
it does.); and (ii) can all versions of Elixir be recreated from
source? If yes and yes, then I think this is sufficient.
> Hi,
>
> It is lost, but can be recreated easily by feeding the old
> flat-fielding and ZPs database to Elixir.
>
> Something we ought to do is preserve the FITS headers: this
> is our only tracer. JJ, can you take a snapshot of these
> headers and preserve them as the B1/2/3 Elixir set?
>
> Jean-Charles.
>
>> Does this mean that the old preprocessing data is lost forever,
>> or is it backed up somewhere?
>>
>> > Hi,
>> >
>> > I understand then that CADC is ready today to accept the reprocessed
>> > files and they'll replace automatically the old ones, and Terapix will
>> > be able to see/get them right away?
>> >
>> > The PI 07B DADS CFHT distribution is complete, and the machines are
>> > available
>> > now for the LS reprocessing - I have not heard about data transfer
>> speed
>> > improvement from Kanoa, that will be the key factor for getting all
>> the
>> > data
>> > in time for a spring T0005 release.
>> >
>> > Jean-Charles.
>> >
>> >> Hi,
>> >>
>> >> I support the least effort option, after considering the scientific
>> >> issues. Let's just replace.
>> >>
>> >> David
>> >>
>> >>
>> >> Séverin Gaudet wrote:
>> >> > I support the least effort option, i.e., replacement. I do
>> recognise
>> >> > that my answer is based on technical reasons and not on scientific
>> >> > reasons.
>> >> >
>> >> > Séverin
>> >> >
>> >> > On Mar 4, 2008, at 5:40 PM, Jean-Charles Cuillandre wrote:
>> >> >
>> >> >>
>> >> >> Hi JJ,
>> >> >>
>> >> >> I am afraid the long path is going to take some time to realize,
>> >> >> weeks at least, while the pressure to move on and start the
>> >> >> reprocessing is rising quickly (specially with possible bandwidth
>> >> >> limitations).
>> >> >>
>> >> >> The initial word I have of Terapix on the first test set is that
>> >> >> it is not worse (nor better) than T0004/3/2 data (that's before
>> >> >> applying a secondary color correction, something I attempted to
>> >> >> explain to you last week). So, there you have it: at worst it
>> >> >> will be the same, actually better since:
>> >> >>
>> >> >> - All data since first light follow the same photom flat
>> recipe
>> >> (B4)
>> >> >> - The major ZPs issues has been smoothed out
>> >> >> - (and I can't imagine all this improvement work on the B4
>> flat
>> >> >> by a bunch of us does not show up in the general data set!)
>> >> >>
>> >> >> I want to say, let's just replace the files and I will document
>> this
>> >> on
>> >> >> the MegaPrime pages asap - the user who pick them up ought to find
>> >> their
>> >> >> way. We will make it clear that CFHT+CADC will do their best to
>> >> support
>> >> >> the old B1/B2/B3 versions if they turn out to be needed for some
>> >> reason.
>> >> >>
>> >> >> The advantage of replacing the files straight is that it saves us
>> >> from
>> >> >> worrying about the replacement later on, no file confusion is
>> >> possible.
>> >> >>
>> >> >> Shall we vote on this?
>> >> >> Jean-Charles.
>> >> >>
>> >> >>> Hi All,
>> >> >>>
>> >> >>> I think the following is the flow of what will/must happen for
>> the
>> >> >>> switch for the current CFHT Elixir data to the CFHT Elixir-B4
>> data.
>> >> >>> Looking at what this will actually involve is starting to make me
>> >> >>> wonder if its worth the effort.
>> >> >>>
>> >> >>> The options available are listed below. Please comment.
>> >> >>>
>> >> >>> JJ
>> >> >>>
>> >> >>>
>> >> >>> a) Overwrite the old files with the new ones as the arrive... not
>> >> get
>> >> >>> worked up about this. 0 effort required.
>> >> >>>
>> >> >>> or
>> >> >>>
>> >> >>> b) the following list of tasks must be completed.
>> >> >>>
>> >> >>> - new archive will be created at CADC called CFHTB4 (JO)
>> >> >>>
>> >> >>> - new top level e-transfer directory will be created on a CFHT
>> >> >>> machine,
>> >> >>> this will be the CFHTB4 archive e-transfer area. (CFHT who?
>> HW?)
>> >> >>>
>> >> >>> - new detrended table at CADC will be created to accept the
>> headers
>> >> >>> of the new CFHTB4 archive. This is a duplicate of the current
>> table
>> >> >>> cfht..detrended and will be called cfht..detrended_b4 (IG)
>> >> >>>
>> >> >>> - The header ingestion script in the CFHT archive
>> (CFHTHIngest.py)
>> >> >>> will be modified to insert into the new 'detrended_b4' tables and
>> >> >>> called (CFHTHIngestB4.py) [JJK]
>> >> >>>
>> >> >>> - a cfhtFileIngest script called cfhtFileIngestB4 will be created
>> >> >>> which knows to call the CFHTIngestB4.py script instead [GM]
>> >> >>>
>> >> >>> - new instance of cfht etransfer will be configured at CADC to
>> add
>> >> a
>> >> >>> new archive called CFHTB4. This script will call
>> cfhtFileIngestB4
>> >> >>> instead of cfhtFileIngest (GM?)
>> >> >>>
>> >> >>> - etransfer will be turned on and accept files for CFHTB4
>> >> >>>
>> >> >>>
>> >> >>> -- Once the entire transfer is finished:
>> >> >>>
>> >> >>> - date to switch to B4 will be agreed on.
>> >> >>> - announcement of date on the CFHT www pages and via CFHTLS
>> list
>> >> >>> will
>> >> >>> occur. [JJK]
>> >> >>> - some 'db magic' will be execute so that the CFHTB4 files
>> >> replace
>> >> >>> the CFHT files and the detrended_b4 entries replace the detrended
>> >> >>> entries. [who ???]
>> >> >>>
>> >> >
>> >>
>> >>
>> >> --
>> >> Dr. David Schade
>> >> Scientist and Group Leader
>> >> Canadian Astronomy Data Centre
>> >> Herzberg Institute of Astrophysics
>> >> National Research Council Canada
>> >
>>
>>
>> -----------------------------------------------------------------
>> Chris Pritchet pritchet at uvic.ca
>> Dept of Physics & Astronomy http://www.astro.uvic.ca/~pritchet
>> University of Victoria
>> P.O. Box 3055 250-721-7744 (office)
>> Victoria, BC V8W 3P6 250-721-7715 (FAX)
>> CANADA
>> -----------------------------------------------------------------
>>
>
-----------------------------------------------------------------
Chris Pritchet pritchet at uvic.ca
Dept of Physics & Astronomy
http://www.astro.uvic.ca/~pritchet
University of Victoria
P.O. Box 3055 250-721-7744 (office)
Victoria, BC V8W 3P6 250-721-7715 (FAX)
CANADA
-----------------------------------------------------------------
Received on Tue Mar 11 2008 - 11:42:18 HST