Embedded Files
BASIC REDUCTION:
Basic reduction has to be done for all kind of data, imaging, specroscopy and to all images, also calibration frames like calibration lamp etc.
If there is overscan area on your images and note X and Y value, where the image should be cut. Go to noao/imred/ccdred.
1. Create Master Bias
combine [input images] [output images] combine=median lsigma=3.0 hsigma=3.0 reject=avsigclip plfile=badpix
2. Bias extraction:
images = [bias.fits] List of CCD images to correct
(output = [masterbias.fits] ) List of output CCD images
(ccdtype= ) CCD image type to correct
(max_cac= 0) Maximum image caching memory (in Mbytes)
(noproc = no) List processing steps only?
(fixpix = yes ) Fix bad CCD lines and columns? if you have the file with badpixels, look at you bias and check f there are any, if so make a badpix.txt file and list in it a column of their x,y values
(oversca= yes ) Apply overscan strip correction? if you have the overscan area, look at bias and science image
(trim = yes ) Trim the image?
(zerocor= yes ) Apply zero level correction?
(darkcor= no ) Apply dark count correction? rearly you need DARK correction
(flatcor= no ) Apply flat field correction?
(illumco= no ) Apply illumination correction?
(fringec= no ) Apply fringe correction?
(readcor= no ) Convert zero level image to readout correction?
(scancor= no ) Convert flat field image to scan correction?
(readaxi= line) Read out axis (column|line)
(fixfile= badpix.txt ) File describing the bad lines and columns
(biassec= [1:300,1300] ) Overscan strip image section
(trimsec= [1:300,1300] ) Trim data section
(zero = masterbias.fits ) Zero level calibration image
(dark = ) Dark count calibration image
(flat = ) Flat field images
(illum = ) Illumination correction images
(fringe = ) Fringe correction images
(minrepl= 1.) Minimum flat field value
(scantyp= shortscan) Scan type (shortscan|longscan)
(nscan = 1) Number of short scan lines
(interac= no) Fit overscan interactively?
(functio= legendre) Fitting function
(order = 1) Number of polynomial terms or spline pieces
(sample = *) Sample points to fit
(naverag= 1) Number of sample points to combine
(niterat= 1) Number of rejection iterations
(low_rej= 3.) Low sigma rejection factor
(high_re= 3.) High sigma rejection factor
(grow = 0.) Rejection growing radius
(mode = ql)
Or shortly: (but be carefull with details)
ccdproc [all_the_images] zerocor=yes zero= masterbias.fits
3. Master Flat
remember ro divid each flat by bias using the command: ccdproc [all_the_images] zerocor=yes zero= masterbias.fits and then:
flatcombine all_flats ccdtype=none
4. Science frame
Use ccdproc to subrtract masterflat from science frame
ccdproc [science_images] flatcor=yes flat=masterflat.fits
SPECTRA REDUCTION:
1. RESPONSE
Is done using the continuum lamp. The illumination of the lamp is not even. This has to corrected before using it for data reduction.
Go to noao/imred/kpnoslit
Added to header DISPAXIS=1 using
hedit [file_name] DISPAXIS 1 add+
Run response :
calibrat= Longslit calibration images put here name of the file of the flat field
normaliz= Normalization spectrum images put here AGAIN name of the file of the continuum lamp
response= Response function images name of the output RESPONSE image
(interac= yes ) Fit normalization spectrum interactively?
(thresho= INDEF) Response threshold
(sample = *) Sample of points to use in fit
(naverag= 1) Number of points in sample averaging
(functio= legendre ) Fitting function
(order = 1) Order of fitting function
(low_rej= 3 ) Low rejection in sigma of fit
(high_re= 3 ) High rejection in sigma of fit
(niterat= 1) Number of rejection iterations
(grow = 0.) Rejection growing radius
(graphic= stdgraph) Graphics output device
(cursor = ) Graphics cursor input
(mode = ql)
response calibrat= Flat.fits
normaliz= Flat1_cut.fits
Type :go and the program will ask if you want to fit interactively. Answer yes. Now you need to fit the dash line to the curve. Change orders by typing :order 15 and press f to fit. You should see dahed line to move towards the curve. If it is not perfect change order. When ready press q to quit.
3. Illumination
images = Longslit calibration images
illumina= Illumination function images
(interac= yes) Interactive illumination fitting?
(bins = ) Dispersion bins
(nbins = 5) Number of dispersion bins when bins = ""
(sample = *) Sample of points to use in fit
(naverag= 1) Number of points in sample averaging
(functio= spline3) Fitting function
(order = 1) Order of fitting function
(low_rej= 0.) Low rejection in sigma of fit
(high_re= 0.) High rejection in sigma of fit
(niterat= 1) Number of rejection iterations
(grow = 0.) Rejection growing radius
(interpo= poly3) Interpolation type
(graphic= stdgraph) Graphics output device
(cursor = ) Graphics cursor input
(mode = ql)
2. Response divide
q science
3. Imcombine science frames
4. Background
5. Extract 1 dimension spectra
apall
6.Calibration
I have cut each line using imcopy
I have added to header DISPAXIS=1 using
hedit file_name DISPAXIS 1 add+
identify name_of_calib_file
m -mark f- fit q-quite l- find rest of the lines
7. Final science calibration
hedit science_frame fields=calib_frame add+
Dispcor - calibrate the science frames
8. See the results:
splot science frame 1
9. Reduce standard star using cal.sol and sci.sof
10 Calculate standard star
standard
11. Calculate sensitivity
sensfunc
12 Flux Calibrate you sci spectra
calibrate
/Applications/scisoft/all/Packages/iraf/iraf/noao/lib/onedstds/ctioextinct.dat
13 Combining spectra
scombine
14 To estimate the redshift extract spectra into text file
wspectext
header=no
MXU REDUCTION:
Response
I have cut each line using imcopy
MOS REDUCTION:
Response
I have cut each line using imcopy
Page updated
Google Sites
Report abuse