iraf.net

From: Olga Kuhn <kuhn@ohia.as.arizona.edu>
Date: May 12, 2005 12:25:56 PM MST
To: fvaldes@noao.edu
Cc: rshaw@noao.edu, mdelapena@as.arizona.edu
Subject: a few questions on WCS for LBT dataHi, I'm working across the street at the LBT, and have been working on
a data
interface document for LBT data with Michelle de La Pena. This document
should lay out the keywords that our 3 baseline instruments: a wide
field
mosaic imager (LBC), and both optical and IR imager/spectrometers should
include in their headers.
We had a few questions, generally about world coordinate systems,
that we
wanted to ask --- The first is how to display the data from the LBC in DS9 with the
proper
on-sky orientation. There are 4 2K x 4K chips: 3 are lined up
parallel to one another and the 4th is rotated 90 degrees and is
above these.
The array layout is similar to that of the WFC at INT. We have a full
set of
ATV, ATM, LTV, LTM, DTV, DTM keywords, and I've been editing these some
according to your document on the web: NOAO Image Data Structure
Definitions;
but have not yet been able to rotate the 4th chip. I gather the LBC
team have
been in touch with you or with Eric Mandel (DS9), but as of last year
this was not resolved. Aside from this rotation, I wanted to ask you about the other WCS
keywords
for the mosaic data, in particular those that account for field
distortion
and those needed to run the data through the mscred reduction package. Finally, I was wondering about the WCS for spectroscopic data (so far
I've not looked into this too much, but was curious how to encode non-
linear
pixel-wavelength solutions). I was wondering if you might have any time this week or early next
week
to meet with Michelle & me about this? cheers,
Olga------------------------------------------------------------------------
-------
Olga Kuhn
Large Binocular Telescope Observatory
University of Arizona e-mail: okuhn@as.arizona.edu
933 N. Cherry Ave FAX: (520) 626-9333
Tucson, Arizona 85721 phone: (520) 626-0809
------------------------------------------------------------------------
-------From: Frank Valdes <valdes@noao.edu>
Date: May 19, 2005 8:39:45 AM MST
To: Olga Kuhn <kuhn@ohia.as.arizona.edu>
Cc: fvaldes@noao.edu, rshaw@noao.edu, mdelapena@as.arizona.edu
Subject: Re: a few questions on WCS for LBT data
Hi Olga,I'm sorry I didn't respond sooner. Concerning the rotated chip, the
current software does not handle this. This was primarily for
efficiency and because we did not have a need. A rotation or
transpose is a little more work than flips in x and y. I don't
suppose you could get the data
transposed as it is being written by the instrument? It could be
added but the metadata would need to be enhanced since an image
sections, i.e. DETSEC, can only describe unrotated regions and flips.I would be glad to talk to you about mosaic data structures and
software. I am free today before 11:15 and after 1;30. I am also
free tomorrow
after 2.Yours,
Frank Valdes
From: Olga Kuhn <kuhn@ohia.as.arizona.edu>
Date: May 19, 2005 10:58:47 AM MST
To: Frank Valdes <valdes@noao.edu>
Cc: fvaldes@noao.edu, rshaw@noao.edu, mdelapena@as.arizona.edu
Subject: Re: a few questions on WCS for LBT dataHi, Would meeting at 2pm this afternoon work out OK? The display issue sounds more difficult than I thought - I'll have to
put the question about transposing while writing out to the LBC team.cheers,
Olga------------------------------------------------------------------------
-------
Olga Kuhn
Large Binocular Telescope Observatory
University of Arizona e-mail: okuhn@as.arizona.edu
933 N. Cherry Ave FAX: (520) 626-9333
Tucson, Arizona 85721 phone: (520) 626-0809
------------------------------------------------------------------------
-------
From: Frank Valdes <valdes@noao.edu>
Date: May 19, 2005 11:05:22 AM MST
To: Olga Kuhn <kuhn@ohia.as.arizona.edu>
Cc: rshaw@noao.edu, mdelapena@as.arizona.edu
Subject: Re: a few questions on WCS for LBT data
Hi,2pm is fine.Frank
x8319 (318-8219)
[The meeting occurred and everyone left satisfied. FV]