Navodila za obdelavo slik
Spremenljivke v kroglastih kopicah
(Restore this version)
Modified: 7 September 2016, 6:19 PM User: Bojan Dintinjana →
Pogledam slike kopice in slabe slike takoj odstranim iz mape. Potem naredim seznam vseh slik v datoteko imlist
$ ls -1 M5_W_?.fts > imlist
$ ls -1 M5_W_??.fts >> imlist
$ ls -1 M5_W_???.fts >> imlist
po potebi še popravim vrstni red slik v urejevalniku teksta,
tako da so slike v kronološkem vrstnem redu. Končnice .fts odstranim. Datoteka izgleda tako:
M5_W_2
M5_W_3
M5_W_4
M5_W_5
M5_W_6
...
Poženem iraf in naložim pakete za profilno fotometrijo:
ecl> noao
noao> digiphot
digi> daophot
Pripravim parametre za fotometrijo:
daophot> imstat M5_W_2 nclip=5
# IMAGE NPIX MEAN STDDEV MIN MAX
M5_W_2 4065336 4858. 116. 4510. 5206.
daophot> datapars
(scale = 1.) Image scale in units per pixel
(fwhmpsf = 4.6) FWHM of the PSF in scale units
(emission = yes) Features are positive?
(sigma = 116.) Standard deviation of background in counts
(datamin = 500.) Minimum good data value
(datamax = 57000.) Maximum good data value
(noise = "poisson") Noise model
(ccdread = "rdnoise") CCD readout noise image header keyword
(gain = "gain") CCD gain image header keyword
(readnoise = 0.) CCD readout noise in electrons
(epadu = 1.) Gain in electrons per count
(exposure = "exptime") Exposure time image header keyword
(airmass = "airmass") Airmass image header keyword
(filter = "filter") Filter image header keyword
(obstime = "mjd") Time of observation image header keyword
(itime = 1.) Exposure time
(xairmass = INDEF) Airmass
(ifilter = "INDEF") Filter
(otime = "INDEF") Time of observation
(mode = "ql")
Nastavim še prag detekcije na 4 sigma, ostalo pusti isto:
daophot> findpars
(threshold = 4.) Threshold in sigma for feature detection
(nsigma = 1.5) Width of convolution kernel in sigma
(ratio = 1.) Ratio of minor to major axis of Gaussian kernel
(theta = 0.) Position angle of major axis of Gaussian kernel
(sharplo = 0.2) Lower bound on sharpness for feature detectio
(sharphi = 1.) Upper bound on sharpness for feature detection
(roundlo = -1.) Lower bound on roundness for feature detection
(roundhi = 1.) Upper bound on roundness for feature detection
(mkdetections = no) Mark detections on the image display?
(mode = "ql")
Poiščem zvezde na prvi sliki,
daophot> unlearn daofind
daophot> daofind M5_W_2
Dobim datoteko M5_W_2.coo.1 v kateri je caa 1500 zvezd, s kar sem zadovoljen. Če je zvezd premalo ali preveč spremenim velikost praga pri detekciji. Za kontrolo zvezde narišem na sliko, še prej nastavim parametre za lep prikaz v tvmark:
daophot> epar tvmark
frame = 1 Default frame number for display
coords = "" Input coordinate list
(logfile = "") Output log file
(autolog = no) Automatically log each marking command
(outimage = "") Output snapped image
(deletions = "") Output coordinate deletions list
(commands = "") Image cursor: [x y wcs] key [cmd]
(mark = "circle") The mark type
(radii = "10") Radii in image pixels of concentric circles
(lengths = "0") Lengths and width in image pixels of concentric rectangle
(font = "raster") Default font
(color = 204) Gray level of marks to be drawn
(label = no) Label the marked coordinates
(number = no) Number the marked coordinates
(nxoffset = 8) X offset in display pixels of number
(nyoffset = 8) Y offset in display pixels of number
(pointsize = 3) Size of mark type point in display pixels
(txsize = 1) Size of text and numbers in font units
(tolerance = 1.5) Tolerance for deleting coordinates in image pixels
(interactive = no) Mode of use
(mode = "ql")
izvedem in dobim sliko, povečen izrez:
daophot> display M5_W_2
daophot> tvmark 1 M5_W_2.fts.coo.1
Super, alogoritem dao je našel skoraj vse zvezde. Datoteko M5_W_2.coo.1 prevedemo v ekvatorialni kordinatni sistem (world) in jo uporabim tudi pri naslednjih slikah:
daophot> epar wcsctran
input = "M5_W_2.fts.coo.1" The input coordinate files
output = ""M5.coo.wcs The output coordinate files
image = "M5_W_2" The input images
inwcs = "logical" The input coordinate system
outwcs = "world" The output coordinate system
(columns = "1 2") List of input file columns
(units = "degres") List of input coordinate units
(formats = "%12.8f") List of output coordinate formats
(min_sigdigit = 11) Minimum precision of output coordinates
(verbose = yes) Write comments to the output file ?
(mode = "ql")
Datoteka zvezde M5.coo.wcs ima koordinate rektascenzija in deklinacija v stopinjah (world ali wcs). Le te so invarjantne na slike, torej na vsaki sliki ima zvezda enako rektascenzijo in deklinacijo, nima pa enakih (logočnih) xy koordinat.
Zdaj lahko na vseh slika kopice naredim grobo aperturno fotometrijo, namreč magnitude bom potreboval pri naslednjih taskih.
daophot> lpar phot
image = "@imlist" Input image(s)
coords = "M5.coo.wcs" Input coordinate list(s) (default: image.coo.?)
output = "default" Output photometry file(s) (default: image.mag.?
skyfile = "" Input sky value file(s)
(plotfile = "") Output plot metacode file
(datapars = "") Data dependent parameters
(centerpars = "") Centering parameters
(fitskypars = "") Sky fitting parameters
(photpars = "") Photometry parameters
(interactive = no) Interactive mode?
(radplots = no) Plot the radial profiles?
(icommands = "") Image cursor: [x y wcs] key [cmd]
(gcommands = "") Graphics cursor: [x y wcs] key [cmd]
(wcsin = "world") The input coordinate system (logical,tv,physica
(wcsout = )_.wcsout) The output coordinate system (logical,tv,physic
(cache = )_.cache) Cache the input image pixels in memory?
(verify = )_.verify) Verify critical phot parameters?
(update = )_.update) Update critical phot parameters?
(verbose = )_.verbose) Print phot messages?
(graphics = )_.graphics) Graphics device
(display = )_.display) Display device
za vsako sliko dobim datoteke .mag.1
Iz prve slike izberem 25 dobrih zvezd za izdelavo modela profila. Izbiram svetle ampak ne saturirane zvezde, v okolici kopice, ki nimajo preveč sosedov, oziroma se ne zlivajo s sosednjimi zvezdami.
daophot> epar pstselect
image = "M5_W_2" Image for which to build psf star list
photfile = "default" Photometry file (default: image.mag.?)
pstfile = "default" Output psf star list file (default: image.pst.?
maxnpsf = 30 Maximum number of psf stars
(mkstars = yes) Mark deleted and accepted psf stars
(plotfile = "") Output plot metacode file
(datapars = "") Data dependent parameters
(daopars = "") Psf fitting parameters
(interactive = yes) Select psf stars interactively?
(plottype = "mesh") Default plot type (mesh|contour|radial)
(icommands = "") Image cursor: [x y wcs] key [cmd]
(gcommands = "") Graphics cursor: [x y wcs] key [cmd]
(wcsin = )_.wcsin) The input coordinate system (logical,tv,physica
(wcsout = )_.wcsout) The output coordinate system (logical,tv,physic
(cache = )_.cache) Cache the input image pixels in memory?
(verify = )_.verify) Verify critical pstselect parameters?
(update = )_.update) Update critical pstselect parameters?
(verbose = )_.verbose) Print pstselect messages?
(graphics = )_.graphics) Graphics device
(display = )_.display) Image display device
daophot> pselect
Z miško gremo na zvezdo in tipka "a" na sliki zvezde in "a" na profilu (a -add star, d- delete star), za vsako zvezdo, končam z "q". Dobim datoteko M5_W_2.pst.1 in jo pretvorimo v world koordnatni sistem:
daophot> epar wcsctran
input = "M5_W_2.pst.1" The input coordinate files
output = "M5.pst.wcs" The output coordinate files
image = "M5_W_2" The input images
inwcs = "logical" The input coordinate system
outwcs = "world" The output coordinate system
(columns = "2 3") List of input file columns
(units = "degres") List of input coordinate units
(formats = "%12.8f") List of output coordinate formats
(min_sigdigit = 11) Minimum precision of output coordinates
(verbose = yes) Write comments to the output file ?
(mode = "ql")
daophot> wcsctran
isto je če tipkam parametre v vrstici:
daophot> wcsctran M5_W_2.pst.1 M5.pst.wcs M5_W_2 logical world columns="2 3" units="degres" formats="%12.8f"in nazaj v logical xy za vsako sliko:
daophot> epar wcsctran
input = "M5.pst.wcs" The input coordinate files
output = "@imlist//.pst.1" The output coordinate files
image = "@imlist" The input images
inwcs = "world" The input coordinate system
outwcs = "logical" The output coordinate system
(columns = "2 3") List of input file columns
(units = "degres") List of input coordinate units
(formats = "%12.8f") List of output coordinate formats
(min_sigdigit = 11) Minimum precision of output coordinates
(verbose = yes) Write comments to the output file ?
(mode = "ql")
daophot> wcsctran
Žal task wcsctran pokvari pravilen format datotek pst od daophota, zato je poterbno popraviti na
pravilen format datotek .pst s zunanjim programom:
$./fformat.py M5_W_*.pst.1
Končno lahko naredim psf profil zvezd za vsako sliko:
daophot> lpar psf
image = "" Input image(s) for which to build PSF
photfile = "default" Input photometry file(s) (default: image.mag.?)
pstfile = "default" Input psf star list(s) (default: image.pst.?)
psfimage = "default" Output PSF image(s) (default: image.psf.?)
opstfile = "default" Output PSF star list(s) (default: image.pst.?)
groupfile = "default" Output PSF star group file(s) (default: image.p
(plotfile = "") Output plot metacode file
(datapars = "") Data dependent parameters
(daopars = "") Psf fitting parameters
(matchbyid = yes) Match psf star list to photometry file(s) by id
(interactive = no) Compute the psf interactively?
(mkstars = no) Mark deleted and accepted psf stars?
(showplots = no) Show plots of PSF stars?
(plottype = "mesh") Default plot type (mesh|contour|radial)
(icommands = "") Image cursor: [x y wcs] key [cmd]
(gcommands = "") Graphics cursor: [x y wcs] key [cmd]
(wcsin = )_.wcsin) The input coordinate system (logical,tv,physica
(wcsout = )_.wcsout) The output coordinate system (logical,tv,physic
(cache = )_.cache) Cache the input image pixels in memory?
(verify = )_.verify) Verify critical psf parameters?
(update = )_.update) Update critical psf parameters?
(verbose = )_.verbose) Print psf messages?
(graphics = )_.graphics) Graphics device
(display = )_.display) Display device
(mode = "ql")
daophot> psf
Pogledam kako izgleda profil zvezde:
daophot> seepsf M5_W_2.psf.1.fts profil.fts
daophot> display profil zscale- zrange- z1=20 z2=5000
Profil je seveda dvodimenzionalna slika, ni slabo! Naredim še enodimenzionalni radialni profil, graf, dobim kar z ukazom imexamine in tipka "r" na sliki:
Zdaj končno naredim profilno fotometrijo, ukaz je allstar, ki naredi fotometrijo za vse zvezde. Sicer imam na voljo še ukaza za fotometrijo ene zvezde peak in fotometrijo skupine zvezd nstar.
daophot> epar allstar
image = "@imlist" Image corresponding to photometry
photfile = "default" Input photometry file (default: image.mag.?)
psfimage = "default" PSF image (default: image.psf.?)
allstarfile = "default" Output photometry file (default: image.als.?)
rejfile = "default" Output rejections file (default: image.arj.?)
subimage = "default" Subtracted image (default: image.sub.?)
(datapars = "") Data dependent parameters
(daopars = "") Psf fitting parameters
(wcsin = )_.wcsin) The input coordinate system (logical,tv,physica
(wcsout = )_.wcsout) The output coordinate system (logical,tv,physic
(wcspsf = )_.wcspsf) The psf coordinate system (logical,tv,physical)
(cache = yes) Cache the data in memory?
(verify = )_.verify) Verify critical allstar parameters?
(update = )_.update) Update critical allstar parameters?
(verbose = )_.verbose) Print allstar messages?
(version = 2) Version
(mode = "ql")
daophot> allstar
in dobim .als.1 datoteke, ki vsebujejo id, xy koordinate, instrumentalne magnitude in napake magnitude.
Instrumentalne magnitude pretvorim v standardne. Potrebujem datoteko primerjalnih zvezd, izberem iz kataloga (Simbad) zvezde, ki so na glavni veji HR diagrama ali imajo barvni indeks B-V med 0.3 in 0.9 in spravim v datoteko comparison.txt, vzorec:
# identifier typ coord1 (ICRS,J2000/2000) Mag B Mag V
2MASS_J15182262+0206397 RG* 15:18:22.624 +02:06:39.73 14.970 14.007
2MASS_J15185239+0203551 RG* 15:18:52.394 +02:03:55.19 15.280 14.340
2MASS_J15184672+0203516 RG* 15:18:46.72 +02:03:51.6 15.670 14.750
potem uporabim program za kalibracijo na standardne magnitude
./allstar.py $(cat imlist)
in dobim datoteke:
imlist.lst seznam slik v obdelavi
starlist.lst seznam vseh zvezd v obdelavi
obslist.std seznam vseh meritev vseh zvezd, magnitude poreračunane na standardne iz primerjalnih zvezd
Iskanje spremenljivk in risanje s programom
./zvezde3.pl obslist.std
Program za vsako zvezdo naredi svetlobno krivuljo in izračuna Stetson-Welch variability index: http://articles.adsabs.harvard.edu//full/1993AJ....105.1813W/0001813.000.html
Za prikaz grafe zberemo v html tabeli: http://dome.ago.fmf.uni-lj.si/podatki/V2016-07-19/obdelava/variable.html
Programi alstar.py, fformat.py in zvezde3.pl so v učilnici v Mapi za izmenjevanje datotek.
Opombe:
slabe slike 20, 38, 33