LCO - MagIC Camera
Quick Reduction of some MagIC Camera data from LCO
1 May 2001
The MagIC is the MIT fast read camera at the Baade telescope. The scale is 0.069"/pix. There is no manual yet.
The raw read format is [2064,2062][ushort]
Estimated gain:
| <> | sig | med | N | ||||
| ll: | |||||||
| 1.974 | 0.106 | 1.974 | 37 | (e-/ADU) | gain | ||
| 15.225 | 1.300 | 15.221 | 37 | (e-) | ron | ||
| lr: | |||||||
| 2.019 | 0.109 | 2.021 | 32 | ||||
| 13.066 | 1.357 | 12.753 | 32 | ||||
| ul: | |||||||
| 2.065 | 0.121 | 2.067 | 34 | ||||
| 12.476 | 1.271 | 12.490 | 34 | ||||
| ur: | |||||||
| 1.890 | 0.125 | 1.881 | 31 | ||||
| 12.562 | 1.305 | 12.822 | 31 |
So a value of 2.0 and 13.5 is fine.
Saturation is about 45000.
| 2.36' | |
| |--------|-------| | |
| | | | |
| E | | | |
| | | | |
| |--------|-------| | |
| N |
CCD REDUCTIONS
This is a quick guess at what to do.
An implot shows the following structure:
x:
1:4 bad
5:1026 good data
1027:1032 bias (exclude 1027 which is slightly high)
1033:1038 bias (exclude 1038 which is slightly high)
1039:2060 good data
2061:2064 bad
y:
1 bad
2:1025 good
1026:1038 bias region (?)
1039:2061 good
2062 bad
I am not sure where there is a "bias" here. I will assume it is in the "x" direction, but will have to check on this.
Rename the images. IRAF does not like names with start with "01" like 010317.010.fits, because it will tranlate it into octal. You have to refer to the data as "010317.010.fits" within IRAF. I changed the names to q*.imh
rename
cpimh *.imh del+
hedit r*.imh observat "lco" up+ ver-
setjd *.imh hjd=""
I wrote a task which pulls apart the 4 quads, reduces them to [OT] and reassembles the image.
To run it, do the following:
1. Set up a special uparm as:
setup:
set stdimage = imt2048
set uparm = /uw50/nick/uparm/magic/
noao
ctio
nickcl
imred
ccdred
keep
Now edit ccdr:
ccdr:
| pixeltype = | "real real") | Output and calculation pixel datatupes |
| (verbose = | yes) | Print log information to the standard output? |
| (logfile = | "logfile") | text log file |
| (plotfile = | "") | Log metacode plot file |
| (backup = | "") | Backup directory or prefix |
| (instrument = | "myiraf$/magic.dat") | CCD instrument file |
| (ssfile = | "myiraf$/magic.sub") | Subset translation file |
| (graphics = | "stdgraph") | Insteractive graphics output |
| (cursor = | "") | Graphics cursor input |
| (version = | "2: October 1987") | |
| (mode = | "ql") | |
| ($nargs = | 0) |
ccdpr:
| images = | "" | List od CCD images to correct |
| (output = | "") | List of output CCD images |
| (ccdtype = | "") | CCD image type to correct |
| (max_cache = | 0) | Maximun image caching memory (in Mbytes) |
| (noproc = | no) | List processing steps only?\n |
| (fixpix = | no) | Fix bad CCD lines and columns? |
| (overscan = | no) | Apply overscan strip correction? |
| (trim = | no) | Trim the image? |
| (zerocor = | no) | Apply zero level correction? |
| (darkcor = | no) | Apply dark count correction? |
| (flatcor = | no) | Apply flat field correction? |
| (illumcor = | no) | Apply illumination correction? |
| (fringecor = | no) | Apply fringe correction? |
| (readcor = | no) | Convert zero level image readout correction? |
| (scancor = | no) | Convert flat fiel image to scan correction?\n |
| (readaxis = | "line") | Read out axis (column|line) |
| (fixfile = | "") | File describing the bad lines and columns |
| (biassec = | "") | Overscan strip image section |
| (trimsec = | "") | Trim data section |
| (zero = | "") | Zero level calibration image |
| (dark = | "") | Dark count calibration image |
| (flat = | "") | Flat field images |
| (illum = | "") | Illumination correction images |
| (fringe = | "") | Fringe correction images |
| (minreplace = | 1.) | Minimum flat field value |
| (scantype = | "shortscan") | Scan type (shortscan|longscan) |
| (nscan = | 1) | Number of short scan lines\n |
| (interactive = | yes) | Fit overscan interactively? |
| (function = | "leg") | Fitting function |
| (order = | 1) | Number of polynomial terms of spline pieces |
| (sample = | "*") | Sample points to fit |
| (naverage = | 1) | Number of sample points to combine |
| (niterate = | 1) | Number of rejection iterations |
| (low_reject = | 3.) | Low sigma rejection factor |
| (high_reject = | 3.) | High sigma rejection factor |
| (grow = | 0.) | Rejection growing radius |
| (mode = | "ql") |
magic.dat:
| subset | filtert | |||
| exptime | exptime | |||
| darktime | darktime | |||
| imagetyp | imagetyp | |||
| biassec | biassec | |||
| datasec | datasec | |||
| trmsec | trimsec | |||
| fixfile | fixfile | |||
| FOCUS | ||||
| OBJECT | object | |||
| DARK | zero | #Old software | ||
| FLAT | flat | |||
| BIAS | zero |
magic.sub
| 'MagIC_t0' | opaque | |
| 'MagIC_B' | B | |
| 'V_LC3014' | V |
ccdmagic:
| images = | "q*.imh" | input images |
| (bias1 = | "[1028:1032,2:1025]") | bias for ll amp |
| (bias2 = | "[1033:1037,2:1025]") | bias for lr amp |
| (bias3 = | "[1028:1032,1039:2061]") | bias for ul amp |
| (bias4 = | "[1033:1037,1039:2061]") | bias for ur amp |
| (trim1 = | "[5:1026,2:1025]") | trim for ll amp |
| (trim2 = | "[1039:2060,2:1025]") | trim for lr amp |
| (trim3 = | "[5:1026,1039:2061]") | trim for ul amp |
| (trim4 = | "[1039:2060,1039:2061]") | trim for ur amp |
| (prefix = | "r") | Prefix for reduced data |
| (niter = | 3) | Number of iterations for bias |
| (reject = | 2.5) | Low and high sigma rejection |
| (imglist = | "tmp$tmp15763ka") | |
| (mode = | "ql") |
Combine the biases as:
zerocomb @inbias out=Zero
Combine the flats:
flatcomb @inb
flatcomb @inv
Now process the data as:
ccdpr r*.imh
(note: I forgot to change the IMAGETYP on some of the "focus" frames that were labeled "FLAT" to "OBJECT". For some reason, the ccdmagic processing clipped the data at 0 with no negative values. I can't figure out why it did this, but make sure that IMAGETYP is set correctly before doing ccdmagic and ccdpr)
EDIT IN THE AIRMASS
hedit ra,dec,epoch into the header.
To do this, you must enter the value twice (an IRAF bug) or use my script editcoord:
editcoord @in10 "07:24:15" "-00:32:55" 2000.
editcoord @in11 "11:01:36.4" "-06:06:32" 2000.
editcoord @in12 "10:50:03" "-00:00:32" 2000.
etc.
Now calculate the ST. I will write an IRAF task to do this later.
hsel d*.imh $I,date-obs,ut yes > junk
trans junk "-" " " | trans STDIN '"' " " > junk1
filecalc junk1 "$2; $3; $4; $5-4" form="%3d%3d%3d\t%h13" > junk2
junk2 should have:
yyyy mm dd LT
where LT is local time (!). You had better check that this is correct!
Then run
asttimes files=junk2 observatory=lco
This outputs a text file with the ST. Edit this file to input the ST into the header.
hedit r*.imh $I,st yes
(you have to run this twice to get the proper units)
Calculate the airmass:
setairmass @in1 observatory=lco
Put in the hour angle.
hedit @in1 ha '(st-ra)' add+
DAOPHOT (the following is pretty specific to my reduction programs)
copy the *.opt files, *.lib, *.tfm
Make the *.inf file
hsel @in1 $I,filtert,ut,airmass,exptime,jd,title,ha yes > junk1.dat
translit junk1.dat '"' ' ' > junk.dat
!$myprog/prog3a junk.dat
/uw50/nick/daophot/irafstuff/filters_magic.dat
2. Measure the FWHM as:
del junk.dat
yaloshift @in1
etc.
Then run
$myprog/prog39 junk.dat
3. For standards, run BFIND2,using thresh about 12 for the bright stars.
4. DAOGROW
ls -1 *.ap > magic.lis
Use 3 unknowns, 0.9 0 for the last two, and set the uncertainty to 0.02.
5. DAOMATCH, DAOMASTER
Use DAOMATCH or run yalocen on the data followed by.
$myprog/prog52a junk.dat
head -1 temp.mch
mv temp.mch xxx.mch
or
sed s/tot/als/ temp.mch > rxxx.mch
For then input to DAOMASTER use:
ty myiraf$/in4_yaloopt
7. Display each first image in the *.mch files.
Run the iraf task "fetch" and then the fortran task "fetch" to make the *.fet files.
8. Enter the data into COLLECT. Use prog43 to speed things up.
!$myprog/prog43 ccd12.mch
COLOR TERMS
The BV color solution for this night was based on 27 standards, of two fields (Ru149 and pg1047) taken at the same airmass but 4 hours apart. The night looked quite photometric.
M1=I1+I2
M2=I1
I1=M2
I2=M1-M2
O1 = M1 + A0 + A1*I2 + A2*X + A3*T
O2 = M2 + B0 + B1*I2 + B2*X + B3*T
A2=0.24
A3=0. m:b,v, I:V,B-V
B2=0.12
B3=0.
A0 = -1.1355085 0.0061041 <<
A1 = -0.0297454 0.0108595 <<
B0 = -1.4578034 0.0057458 <<
B1 = 0.0581488 0.0096709 <<
S1 = 0.0177567 <<
S2 = 0.0197406 <<
So:
b = B + -0.030*(B-V) + zp
v = V + +0.058*(B-V) + zp
The V term is a bit higher than usual.
The range in color was (-0.11,1.12). The color terms were not very linear and the fits were not very good, even though the data are extremely photometric. That is why the residuals had an extra scatter (S1,S2) of 0.017 and 0.019mag. The color term may be quadradic. For a
photometric night on smaller telescopes, these are 0. There may be a small photometric gradient in x of about 0.04mag. Without more standards, I can't say.
mag at 1ADU/s
B 26.17
V 26.42
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