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Vvedenie v IRAF

Etot dokument yavlyaetsya kratkim vvedeniem v IRAF (the Image Reduction and Analysis Facility). IRAF - eto "universal'nyi paket programm dlya obrabotki i analiza astronomicheskih dannyh", razrabotannyi gruppoi IRAF v Nacional'noi Opticheskoi Astronomicheskoi Observatoriii (NOAO). Eto uchebnoe posobie mozhet stat' horoshim vstupleniem dlya studentov, kotorye nachinayut nauchnuyu rabotu i nuzhdayutsya v izuchenii IRAF. Eto posobie otrazhaet tol'ko osnovnye vozmozhnosti IRAF, nekotorye primery, rassmotrennye v posobii, osnovany na nashem lichnom opyte. Na etih primerah vy smozhete izuchit' bolee slozhnye programmnye pakety.

Dannoe posobie bylo sostavleno Vol'novoi A.A.(alinus@yandex.ru) i Shul'goi A.P.(babouche@yandex.ru) na osnove dokumenta Dzhosha Valavendera Introduction to IRAF.

Skachat' sam paket programm IRAF mozhno na oficial'nom saite http://iraf.noao.edu/. Takzhe vy mozhete vospol'zovat'sya uzhe gotovym arhivom iraf-2.12.2a.slackware-10.2.tar.gz (40Mb). Fail README.iraf soderzhit kratkoe poyasnenie k nemu).

Etot arhiv byl ustanovlen na Linux Slackware 10.2.

Oglavlenie

1. Konfiguraciya i zapusk IRAF

1.1 Predvaritel'nye zamechaniya

Pri rabote s IRAF vy vzaimodeistvuete s dvumya komandnymi sredami: UNIX i IRAF CL (CL podderzhivaet interfeis komandnoi stroki). Chtoby provesti razlichiya mezhdu etimi dvumya komandnymi strokami, my budem prisoedinyat' komandnuyu podskazku k stroke so vsyakoi komandoi, kotoruyu my privodim v kachestve primera. Pri rabote v UNIX my budem ispol'zovat' %, a pri rabote v IRAF CL - cl>. Zamet'te, chto podskazki, kotorye vy vidite pri rabote v vashei sisteme, mogut otlichat'sya ot etih. V etom posobii my predpolagaem , chto chitatel' uzhe neploho razbiraetsya v UNIX. Esli vam neizvesten UNIX, vy mozhete ispol'zovat' posobie Dzhosha Valavendera po UNIX.

Tak zhe kak i UNIX, IRAF chuvstvitelen ko vsem komandam i nazvaniyam failov. Fail image.fits otlichaetsya ot faila Image.fits i ot faila image.FITS, tak chto bud'te ostorozhny s bol'shimi i malen'kimi bukvami.

1.2 Ispol'zovanie komandy mkiraf.

IRAF trebuet konfiguracionnyi fail (login.cl) i papku dlya sohraneniya parametrov pol'zovatelya (uparm). Rekomenduetsya sozdat' papku IRAF v svoei domashnei direktorii (~/iraf/) dlya hraneniya etih failov. Komanda mkiraf sozdaet neobhodimye login.cl i uparm faily v direktorii, v kotoroi vy rabotaete.

% cd
% mkdir iraf
% cd iraf
% mkiraf
 -- creating a new uparm directory
Terminal types: xgterm,xterm,gterm,vt640,vt100,etc.
Enter terminal type: xgterm
A new LOGIN.CL file has been created in the current directory.
You may wish to review and edit this file to change the defaults.

Kogda po scenariyu mkiraf sprashivaet vas tip terminala, napechataite xgterm. U IRAF est' neskol'ko graficheskih interfeisov, kotorye vam zahochetsya ispol'zovat' pri rabote s izobrazheniyami. Eto budet rabotat' dolzhnym obrazom togda, kogda vy zapuskaete IRAF iz xgterm.

1.3 Otkrytie xgterm.

Chtoby otkryt' xgterm, napechataite xgterm v komandnoi stroke UNIX:

% xgterm &

Vam sleduet vsegda zapuskat' IRAF iz xgterm. Nekotorye iz komand IRAF ispol'zuyut special'nye svoistva xgterm dlya sozdaniya interaktivnyh graficheskih okon, kotorye vy mozhete ispol'zovat' dlya operacii s dannymi. Obychno vam nuzhen tol'ko odin xgterm, v kotorom rabotaet IRAF. Odnovremenno u vas mogut byt' otkryty obychnye terminaly (t.e. xterm), tak chto vy mozhete videt', kakie faily lezhat v papke, gde vy rabotaete.

1.4 Redaktirovanie vashego faila login.cl.

Prezhde chem vy nachnete rabotu, otredaktiruite fail login.cl, chtoby on otrazhal lokal'nye nastroiki vashei sistemy. V UNIX voidite v papku ~/iraf/ i otkroite login.cl, ispol'zuya vash lyubimyi tekstovyi redaktor. Vo-pervyh, naidite strochku, v kotoroi napisano:

#set stdimage = imt800

Dlya nas eto stroka 27.

Tak zadaetsya defoltnyi razmer otobrazhaemoi oblasti v pikselyah. Znachok reshetki (#) oznachaet, chto eta stroka zakommentirovana i ne chitaetsya IRAF. Esli by eta programma rabotala (bez znachka kommentariya), razmer kartinki byl by 800h800 pikselei. Esli vy ispol'zuete IRAF dlya obrabotki izobrazhenii, poluchennyh na professional'noi observatorii, rekomenduem zadat' parametr 4096, esli vy ispol'zuete kameru v SBO, rekomenduem postavit' 2048. Takim obrazom, udalite znachok kommentariya i zamenite 800 na nuzhnoe znachenie. Naprimer, v nashem login.cl, eta strochka vyglyadit tak (zamet'te, chto znak # ubran iz nachala stroki):

set stdimage = imt4096

Drugaya strochka v login.cl, kotoruyu nado izmenit', vyglyadit tak:

#set imtype = "imh"

Dlya nas eto 34 stroka.

Eto zadaet defoltnyi tip izobrazheniya. V teh sluchayah, kogda v imeni faila net rasshireniya, IRAF avtomaticheski podrazumevaet rasshirenie po umolchaniyu. Tip imh razrabatyvalsya special'no dlya IRAF, odnako bol'shinstvo PZS dannyh poluchayut v formate FITS. Izmenite etu strochku (ne zabud'te ubrat' simvol #):

set imtype = "fits"

1.5 Zapusk IRAF.

Chtoby zapustit' interfeis komandnoi stroki IRAF, ispol'zuite komandu cl (vsegda pomnite, chto zapuskat' IRAF nado iz xgterm, a ne iz obychnogo xterm). Takzhe pomnite, chto IRAF nuzhno zapuskat' iz toi direktorii, gde nahoditsya login.cl.

% cd ~/iraf
% cl

NOAO PC-IRAF Revision 2.12.1-EXPORT Fri Jul 12 15:54:09 MST 2002 
This is the EXPORT version of PC-IRAF V2.12 supporting most PC systems.

Welcome to IRAF.  To list the available commands, type ? or ??.  To get 
detailed information about a command, type `help command'.   To  run  a command 
 or  load  a  package,  type  its name.   Type  `bye' to exit a package, or 
`logout' to get out of the CL.   Type `news'  to  find  out what is new in the 
version of the system you are using.   The following commands or packages are 
currently defined:

      dataio.     language.   noao.       proto.      utilities.  
      dbms.       lists.      obsolete.   softools.   
      images.     mscred.     plot.       system.     
cl>

Dal'she my budem rabotat' skoree v IRAF, chem v UNIX. Esli vy zapustili IRAF iz papki, gde net login.cl, vy poluchite takoe soobshenie:

Warning: no login.cl found in login directory

Udobno bylo by sozdat' simvol'nuyu ssylku na login.cl iz domashnei direktorii, chtoby IRAF mozhno bylo zapuskat' iz nee:

% cd ~
% ln -s ~/iraf/login.cl login.cl

Gde ~/iraf/login.cl - mesto nahozhdeniya login.cl. Teper' vy mozhete zapuskat' IRAF iz vashei domashnei direktorii.

2. Vzaimodeistvie s CL.

2.1 Komandy UNIX i IRAF.

Nekotorye osnovnye komandy UNIX sushestvuyut takzhe i v IRAF, naprimer: ls, mkdir, mv, cd, grep i mnogie drugie.

Zametim, chto komanda rm ne rabotaet v IRAF, odnako, ee zamenyayut dve drugie komandy: imdel i del.

Pochti vse upravlenie IRAF osushestvlyaetsya cherez razlichnye komandy. Pohozhie komandy gruppiruyutsya v pakety. Razlichnye pakety s osnovnymi komandami uzhe zagruzheny. Esli vy uzhe zashli v IRAF, napishite komandu ? v CL

cl> ?
      dataio.     language.   noao.       proto.      utilities.  
      dbms.       lists.      obsolete.   softools.   
      images.     mscred.     plot.       system.

Eto spisok dostupnyh paketov. Nekotorye pakety soderzhat v sebe drugie, eto chasto oboznachaetsya tochkoi posle nazvaniya paketa ( t.e. images.imutil). Dlya polucheniya spiska dostupnyh komand, napishite ?? v CL.

 cl> ??
    clpackage:
      dataio.     language.     noao.       proto.   utilities.  
      dbms.       lists.      obsolete.   softools.   
      images.     mscred.       plot.       system.     
    language:
      access      clear       eparam      jobs        print       set
      back        defpac      error       keep        printf      show
      beep        defpar      flprcache   kill        putlog      sleep
      bye         deftask     fprint      logout      radix       stty
      cache       defvar      fscan       lparam      redefine    task
      cd          dparam      gflush      mktemp      reset       time
      chdir      edit        hidetask    osfn        scan        unlearn
      cl.         ehistory    history     package     scanf       update
      clbye       envget      imaccess    prcache     service     wait
    noao:
      artdata.      digiphot.     nobsolete.    onedspec.     
      astcat.       focas.        nproto.       rv.           
      astrometry.   imred.        observatory   surfphot.     
      astutil.      mtlocal.      obsutil.      twodspec.     
    

utilities:
      curfit    entab     polyfit   surfit    ucase     
      detab     lcase     split     translit  urand     
    proto:
      binfil            hfix              irafil            rskysub
      bscale            imcntr            joinlines         suntoiraf
      epix              imextensions      mimstatistics     text2mask
      fields            imscale           mskexpr           
      fixpix            interp            mskregions        
    tv:
      display     iis.        imedit      imexamine   tvmark      wcslab
    dataio:
      bintxt      mtexamine   rfits       txtbin      wtextimage  
      export      rcardimage  rtextimage  wcardimage  
      import      reblock     t2d         wfits       
    plot:
      calcomp    gkidir      imdkern     phistogram  sgidecode   surface
      contour    gkiextract  implot      pradprof    sgikern     velvect
      crtpict     gkimosaic   nsppkern    prow        showcap     
      gdevices    graph       pcol        prows       stdgraph    
      gkidecode   hafton      pcols       pvector     stdplot     
    imutil:
      chpixtype     imdelete      imheader      imslice       listpixels
      hedit         imdivide      imhistogram   imstack       minmax
      hselect       imexpr        imjoin        imstatistics  sections
      imarith       imfunction    imrename      imsum         
      imcopy        imgets        imreplace     imtile        
    immatch:
      geomap     gregister   imcombine   skymap    wcscopy     wregister
      geotran     imalign    linmatch    skyxymatch  wcsmap    xregister
      geoxytran   imcentroid  psfmatch  sregister  wcsxymatch  xyxymatch
    imgeom:
      blkavg        im3dtran      imshift       magnify       shiftlines
      blkrep        imlintran     imtranspose   rotate        
    imfit:
      fit1d       imsurfit    lineclean   
    imfilter:
      boxcar    fmedian   frmedian  gauss     laplace   mode      rmode
      convolve  fmode     frmode    gradient  median    rmedian   
    imcoords:
      ccfind      ccsetwcs    ccxymatch   starfind    wcsreset    
      ccget       ccstd       imcctran    wcsctran    
      ccmap       cctran      skyctran    wcsedit     
    images:
      imcoords.   imfit.      immatch.    tv.         
      imfilter.   imgeom.     imutil.     
    user:
      adb      cp       fc       lpq      mv       rlogin   sps      vi
      bc       csh      find     lprm     nbugs    rsh      strings  w
      buglog   date     finger   ls       nm       rtar     su       wc
      cal     dbx      ftp      mail     od       ruptime  sync     wtar
      cat      df       gdb      make     pg       rusers   telnet   xc
      cls      diff     generic  man      ps       rwho     tip      
      clw      du       grep     mkpkg    pwd      sh       top      
      comm     emacs    less     mon      rcp      spell    touch    
    system:
      allocate      devstatus     lprint        page          sort
      concatenate   directory     match         pathnames     spy
      copy          diskspace     mkdir         phelp         tail
      count         files         mkscript      protect       tee
      deallocate    gripes        movefiles     references    type
      delete        head          netstatus     rename        unprotect
      devices       help          news          rewind        
    lists:
      average     lintran     rimcursor   tokens      words       
      columns     rgcursor    table       unique

Kak vidite, eto obychno dlinnyi spisok.

2.2 Rabota s komandami.

Davaite poprobuem seichas porabotat' s nekotorymi iz etih komand. Zdes' predpolagaetsya, chto u vas uzhe est' neskol'ko izobrazhenii, s kotorymi mozhno rabotat'. Esli vy rabotaete s izobrazheniyami dlya ASTR 3510/3520 oni skoree vsego polucheny s pomosh'yu SBO. Esli tak, udostover'tes', chto oni perevedeny v nuzhnyi format. S etogo momenta nazvanie lyubogo izobrazheniya, s kotorym vy rabotaete, budet zamenyat'sya na imagename, inogda k nemu budet dobavlyat'sya "hvostik", oznachayushii fil'tr, naprimer imagename_V.

Naprimer, vospol'zuemsya komandoi imstat:

cl> imstat imagename
#        IMAGE       NPIX      MEAN    STDDEV       MIN       MAX
   030_n2392_300_V  173400    33556.     574.5      253.    63567.

Zametim, chto kogda my pechataem nazvanie izobrazheniya, my mozhem otbrosit' rasshirenie .fits, potomu chto v faile login.cl my ustanovili tip izobrazheniya fits, i IRAF po umolchaniyu dopisyvaet nazvaniyu izobrazheniya rasshirenie .fits.

imstat pokazyvaet osnovnye dannye ob izobrazhenii.

2.3 Izmenenie parametrov komand v CL.

Kazhdaya komanda IRAF imeet nabor parametrov , kotorye opredelyayut deistviya komandy. Eto glavnym obrazom vhodnye i vyhodnye dannye, a takzhe opcii, kotorye vhodyat v komandu. Chtoby uvidet' parametry, kotorye ispol'zuyutsya v komande, ispol'zuite komandu lpar.

cl> lpar imstat
    images = "030_n2392_300_V" List of input images
   (fields = "image,npix,mean,stddev,min,max") Fields to be printed
   (lower = INDEF)          Lower limit for pixel values
   (upper = INDEF)          Upper limit for pixel values
   (nclip = 0)              Number of clipping iterations
   (lsigma = 3.)            Lower side clipping factor in sigma
   (usigma = 3.)            Upper side clipping factor in sigma
   (binwidth = 0.1)           Bin width of histogram in sigma
   (format = yes)           Format output and print column labels ?
   (cache = no)            Cache image in memory ?
   (mode = "ql")

Zdes' dva vida parametrov: te, kotorye trebuyut vvedeniya, kogda my zaprashivaem komandu, i parametry po umolchaniyu, kotorye ne nuzhdayutsya v opredelenii (skrytye parametry). Parametry, trebuyushie vvedeniya, ne imeyut poyasnitel'noi frazy v spiske lpar. V sluchae imstat edinstvennym trebuemym parametrom, yavlyaetsya nazvanie izobrazheniya (ili spisok nazvanii izobrazhenii), dlya kotoryh vy hotite poluchit' informaciyu. Esli vy propustite kakoi-nibud' iz etih parametrov, IRAF soobshit vam ob etom.

Vtoroi tip parametrov zaklyuchen v skobki v spiske lpar. Ih ne nado opredelyat', kogda vy pol'zuetes' komandoi, esli vy ih ne opredelili, togda ispol'zuyutsya znacheniya po umolchaniyu.

Chtoby uznat', chto oboznachat kazhdyi iz parametrov, vy mozhete posmotret' spravochnuyu stranicu dlya etoi komandy.

cl> help imstat

IMSTATISTICS (Feb01)         images.imutil        IMSTATISTICS (Feb01)

NAME
    imstatistics -- compute and print image pixel statistics
    
    
USAGE   
    imstatistics images
    
PARAMETERS
    
    images
        The input images or image sections for which pixel  statistics are to 
be computed.
    
    fields = "image,npix,mean,stddev,min,max"
        The statistical quantities to be computed and printed.
    
    lower = INDEF
        The  minimum  good data limit.  All pixels are above the default value 
of INDEF.
    
    upper = INDEF
        The maximum good data limit.  All pixels are above  the  default value 
of INDEF.

V spravke napisano bol'she, no my opustili ostavsheesya. Verhnyaya strochka rasskazyvaet o nazvanii komandy i paketa, v kotorom ona nahoditsya. Razdel USAGE opredelyaet cl komandu i poryadok vvoda (v dannom sluchae tol'ko odin). Razdel PARAMETERS opisyvaet vse parametry i vvodimye dannye. Chtoby opredelit' dopolnitel'nye (skrytye) parametry v cl, ispol'zuite format parametername=value. Naprimer:

cl> imstat imagename binwidth=0.4
#    IMAGE          NPIX      MEAN    STDDEV       MIN       MAX
030_n2392_300_V    173400    33556.     574.5      253.    63567.

Zametim, chto snachala opredelyaetsya neobhodimye vhodnye parametry v tom poryadke, v kotorom oni opisany v spravke, zatem opredelyayutsya dopolnitel'nye (skrytye) parametry. Nekotorye skrytye parametry dvoichny (u nih est' tol'ko dva znacheniya, da ili net). Chtoby opredelit' ih, mozhno napechatat' parametername=yes ili parametername=no v cl, ili ukorochennyi variant parametername+ ili parametername- dlya yes ili no sootvetstvenno.

Nado upomyanut' ob eshe odnom ukorochennom variante: v IRAF ne nuzhno pechatat' polnoe nazvanie komandy ili parametra, mozhno ukazat' tol'ko neskol'ko pervyh bukv tak, chtoby okonchanie dlya nih bylo edinstvennym. My uzhe eto ispol'zovali: polnoe nazvanie komandy imstat - imstatistics. Naprimer:

cl> imstat imagenam