To use Charon to examine drift scan images,
fill in the
settings in Charon like this:
|
Report file name |
mpc.log |
Saturation point |
32000 |
|
Cutoff point |
0.950 |
Focal len (inches) |
29.53 |
|
Image offset |
0 |
Pix width (microns) |
9.00 |
|
Scale tolerance |
0.010 |
Pix height(microns) |
9.00 |
|
Search distance |
0.50 |
SBIG file format: Image is uninverted |
|
|
Observer code |
0 |
Match to GSC-ACT |
|
|
Time offset |
0.0 |
File date gives end of exposure |
|
|
Maximum residual |
1.0 |
Mag limit: |
18.00 |
|
Number stars used |
7 |
D:\GJG\TAU20.ST7 |
|
|
White stars on black |
Object name: |
GSC 1267 237 |
|
|
RA/dec in decimal seconds |
Simple centroiding |
||
|
Video mode: |
320 x 200 |
Max tilt angle: |
90.00 +/- 4.00 |
|
Linear (first-order) fit |
Photometric band: |
||
|
Centroid size |
5 |
Save settings |
Charon will calculate a correct mid exposure time for drift scan images .
( but
only outside the ramping )
In images in SBIG file format, a line:
Note = Sekunden je Reihe 0.17810216469252
should be present
or start Charon with the argument -d
To use drift scanned FITS files, start Charon always with the argument -d
To start Charon with the argument -d, first start Charon without arguments and
fill in the settings, and then start Charon with the argument -d, you may
add arguments for the image file and for the object like:
C:\GuideDN\jup_part.fit -ogsc 1895 575 -d
The time and date in the file info of
an image taken by WinScan, will indicate the time, when the first line
of the image is read out. Therefore in Charon it is
necessary to set: File date gives end of exposure
In files sliced
from JimsSilce or ViewScan the time in the file info is also the
time, the first line (of the new file) is read out, same settings as
mentioned before.
When using FITS files you must fill in the focal len and
the pixel size in Charon in the settings, using SBIG files, these
values are taken from the file header.
It is also important to set:
Images SBIG file format: Image is uninverted
Images FITS file format: Image is inverted
Max tilt angle: 90.00 +/- 4.00
(Max tilt angle: 90.00 +/-
1.00 should also work)
(In images taken by WinScan West is at the
top)
In large images,it should be set:
Maximum residual
2.0
Search distance 2 or 4 or more, depends on the size of the
image
If Charon don't works with that settings, try to change
some items
It may be easier to use smaller or sliced images
(I
got Charon work with images up to 765 * 10000 pixels, but the
settings in Charon have to be adjusted very carefully)
In large
images, it may help, to fill in the exact RA and DEC of the center of
the image (at Object name)(ViewScan can calculate the center of an image).
Video mode: try different settings