Project-Management Blog
for IRAF Support
in the NStars Data-Reduction Work
of Prof. Richard O. Gray and His Colleagues

For the visitor in a hurry, here's an overview with hyperlinks to the relevant sections, further down this destined-to-become-long page.

The first section, 'Background', is liable to change every couple of months. The second section, 'Discursive Diary' and the third section, 'Terse Timelogs', are liable to change once a week, typically at some point on a Monday.

0. Background

Here I blog my ongoing, long-term self-education and technical-support effort as a member of the NStars observing and (IRAF) data-reduction team of Prof. Richard O. Gray. Prof. Gray's home institution is Appalachian State University. Prof. Gray's principal doctoral-level collaborators are Prof. Emeritus Robert F. Garrison in the University of Toronto and Christopher J. Corbally, S.J., of the Vatican Observatory Research Group in Tucson.

This project is coded in my general project-management and timelogging formalism as 20060101T140000Z__gray_nstars. The project is a sequel to a preliminary IRAF review (refresher), coded in the same formalism as 20051228T235959Z__iraf. That 20051228T235959Z__iraf project ran from around 2005-12-01 to 2006-02-13 for an investment of 38 hours and 53 minutes, and was itself a sequel to a big IRAF project on the helium-weak star HD21699 for Prof. Robert F. Garrison in the 1998-99 University of Toronto course AST425.

The following are my current working conditions:

• Occasional depressions pose no significant risks.
• Police surveillance of my ongoing half-hour Monday and Friday vigils at the USA Toronto Consulate in support of my friend the peace activist Jim Loney, hostage in Baghdad since 2005-11-26 to unknown elements operating under the name "Swords of Righteousness Brigade", poses no significant risks.
• My work is under a 25% probability of interruption, on essentially no advance notice, for a period of up to 30 days, if an agency of the Canadian federal government exercises its standing option to have me deliver LaTeX physics-copyedit services. The agency last exercised this option in 2005 September.
• Technical work will come nearly to a halt in the periods 2006-04-05/2006-04-08, 2006-04-10/2006-04-13, and 2006-04-17/2006-04-18 as I mark high-school-level exams for an agency of the Ontario provincial government.
• Technical work will slow down moderately for two-week periods in 2006 May and 2006 September and 2006 December as I temporarily transfer operations to my mother's (Linux-equipped, IRAF-networked) flat in Nova Scotia (62 Willow Street, Truro NS B2N 4Z6; telephone 902-897-0236; it is believed at present that I have a rail departure from Toronto for Truro 2006-05-07 and a rail arrival in Toronto from Truro 2006-05-25).
• Technical work will slow down severely for a period of roughly two weeks around 2006-06-03 as I attend to a family wedding near Vancouver and to other matters involving family and possibly also involving non-family friends. None of these foreseen activities takes me out of Canada. I anticipate spending many days in the train, with an itinerary including at least Toronto-Vancouver (a three-day train journey) and Vancouver-Toronto, possibly with one or two stopovers.

1. Discursive Diary (Latest First)

20060329T211556Z:

Again, a subdued-but-not-terrible week, rather notably marked first by depression, then by the joyous news of my friend Jim Loney's rescue in Baghdad. Depression after the end of the week has caused me to be slow in posting this blog entry, sorry! Total time spent in the week was 08h01, not counting some minor reading on statistics that will later come in handy in learning about Poisson noise.

I moved forward with my IRAF review, to a point where I extracted spectra, albeit without wavelength calibration, generated by the artificial-data task artdata. I also read a good chunk of Steve B. Howell's excellent Handbook of CCD Astronomy (Cambridge, 2000).

20060321T034633Z:

This was a subdued-but-not-not-terrible week, with a total hourcount of 09h14. I have now generated artificial spectra in IRAF with artdata, and I suppose will later find the artdata provisions for tweaking the amount of inserted noise useful in mastering S/N concepts (including the notions of variance and standard deviation in a Poisson distribution). I have been examining my artdata spectra with ximtool. It will be useful in future to use what turns out to be an interesting feature of ximtool, namely its provisions for working with bad-pixel masks, in particular for flagging masked pixels.

Here is a little scrap of IRAF lore which may or may not be useful to the team: the alternative to ximtool, namely DS9 (which itself used to be called SAOimage) has a reference manual or similar documentation at http://hea-www.harvard.edu/RD/ds9/. This point addresses a long-standing problem in the DDO warmroom, where we use DS9 in place of ximtool for initial quality control, and where we have traditionally found ourselves groping without a manual.

20060313T215651Z:

This was a bad week, with depression in the closing days of the week. I was culpable in surrendering to the depression. I did almost nothing on NStars, although I did carry on in a modest way with private maths study (of surface integrals), some ham-radio training (with 14 Morse letters now mastered at 15 words/minute), and some Linux (with a USB hard drive now brought on line, and the fifth edition of the standard O'Reilly Running Linux book now bought and started, as a replacement for my much-used copy of the third edition). The darkness deepend Friday night with the news that the bullet-riddled corpse of Tom Fox, a colleague of my captive friend Jim Loney, had been found amid garbage in Baghdad.

20060304T212432Z:

Because I am completing the fourth week of this project, it becomes appropriate to start a blog, recording what I have learned so far.

(1) It turns out that IRAF installs cleanly on what I am sure is from a computers-in-science-and-engineering-academia standpoint the most appropriate of the Linuxes, Debian GNU/Linux. (I use Debian GNU/Linux 3.1 "Sarge", the latest version in the "stable" branch.) It also turns out that there is no problem with putting the appropriate auxiliary tools xgterm, ximtool, and ds9 onto Debian. All these installations do, admittedly, have to be done by brute force, in other words without the benefit of Debian's own preferred installation tools such as aptitude.

(2) I have also tried to compile Prof. Gray's own tool xmk19 in Debian, but without success so far. The following is a terminal session showing error messages:

((SESSION)) 
$make xmk19
cc     xmk19.c   -o xmk19
xmk19.c:6:22: X11/Xlib.h: No such file or directory
xmk19.c:7:23: X11/Xutil.h: No such file or directory
xmk19.c:8:28: X11/cursorfont.h: No such file or directory
In file included from xmk19.c:10:
xwins.h:5:22: X11/Xlib.h: No such file or directory
xwins.h:6:23: X11/Xutil.h: No such file or directory
((SNIP))
((/SESSION))

My guess is that I need to invoke aptitude to install some currently missing C development library. I will have to come back to this problem eventually.

(3) It turns out that the trio of McFadden principal DDO-specific data-reduction scripts which I have inherited is, at least to an initial and superficial inspection, straightforward. The job of interpreting them is significantly eased by the McFadden documentation at http://stellar.phys.appstate.edu/doc.html. I am still studying the scripts as a preliminary to trying to run them. In the course of the studying (which will surely last many weeks), I am adding various comments to the code.

(4) As a necessary supplement to the script studies, I am doing much reading in IRAF documents from NOAO. (a) It is necessary to look at the online IRAF "help" pages, nowadays conveniently invoked with the paged-help phelp task. A good starting point proves to be phelp apextract.package, because this command pulls up a high-level briefing that itself refers rather systematically to other "help" pages for lower-level details. (b) It is also necessary to look at very roughly ten or fifteen hefty NOAO IRAF documents outside the IRAF "help" pages. Here I have so far spent a lot of time on the Shames-Tody User's Guide to the IRAF Command Language and on the Francisco Valdez paper (ftp://iraf.noao.edu/iraf/docs/apex.ps.Z) "The IRAF APEXTRACT Package".

2. Terse Timelogs (Earliest First)

20060101T140000Z__gray_nstars
20060207=00h40->0000h40__started examining {M.McF} scripts  
20060210=01h52->0002h32__finished prelim examination
                         of {M.McF} scripts and related files
                       __started reading
                         http://stellar.phys.appstate.edu/doc.html
                         (_now at #2.3) 
20060211=02h44->0005h16__finished cursory rdg of 
                         http://stellar.phys.appstate.edu/doc.html
[_here ends WK001 of this project] 
20060213=01h03->0006h19
20060215=02h01->0008h20
20060216=03h07->0011h27__starting writing comments into scripts
20060217=03h19->0014h46__spent 02h26 of this time in study mode
                         __working on Shames-Tody doc _User's
                           Guide to the IRAF Command Language_ 
20060218=02h00->0016h46__spent 02h00 on Shames-Tody
[_here ends WK002 of this project] 
20060224=02h02->0018h48__spent 02h02 on Shames-Tody
20060225=02h41->0021h29__spent 02h41 on Shames-Tody
[_here ends WK003 of this project]
20060228=01h41->0023h10__spent ~01h00 on Shames-Tody 
                         __this Shames-Tody rdg is now finished
20060301=00h24->0023h34
20060302=03h25->0026h59__mainly read IRAF phelp pages
                         and the Valdez APEXTRACT *.ps doc
                         __also did a little commenting of second
                           {M.McF} script
20060303=02h35->0029h34__finished Valdex APEXTRACT *.ps doc etc
                         __worked thru Valdez formulae, 
                           reaching 85% comprehension level 
                           on everything
                           with the exception of the 
                           readout-noise-plus-Poisson
                           modelling of variance
20060304=01h59->0031h33__continued with IRAF phelp topics 
                       __also created project-management blog
                         __but did not put blog creation
                           into this time accounting
[_here ends WK004 of this project] 
20060309=00h20->0031h53__continued with IRAF phelp topics
[_here ends WK005 of this project] 
20060314=03h00->0034h53__continued with IRAF phelp topics
20060315=02h17->0037h10__ditto
20060316=00h59->0038h09__continued with IRAF phelp topics
                       __worked on splot and ximtool
                         __with artificial spectra from artdata
                         __in eonnection with an example
                           from phelp apall
20060317=01h19->0039h28__continued with ximtool
20060318=01h19->0040h47__continued with ximtool
[_here ends WK006 of this project] 
20060320=03h06->0043h53__reviewed bias-frame etc concepts
                         in Howell book
20060321=00h40->0044h33
20060323=00h21->0044h54__read in Howell book
20060324=00h21->0045h15__finished initial review of ximtool 
20060325=03h33->0048h48__extracted spectra generated by artdata 
                         __this is the excercise given
                           in phelp apall
[_here ends WK007 of this project]