Deepsearch Database Image Names
mar697btc652csg.fts
1 2 3 4 5
Every image name has five parts:
1. The date of the image
- The UT date on which the image was aquiried. This will often differ
from the date quoted for the night of observing, because usually the
evening night is quoted, and for most things Chile and westward it is
tomorrow in UT by the time we observe today.... Note that more
recently, we've gone to using four digit dates (counter to this
example).
2. The telescope name
- This is usually a string like "ctio" (for the Prime Focus CCD),
"wiyn", "int", or "btc" (for the BTC at CTIO). In most cases, for
multiple chip cameras, an extra letter at the end will indicate the
chip. For instance, the MOSAIC camera on the Kitt Peak 1m (was it
the 1m?) has telescope names of msca, mscb, mscc, mscd, etc.
3. The run number
- Usually corresponds to the run number at the telescope. With the BTC,
the last digit of the run number tells you which of the four chips
it comes off of. So, in this example, it was chip 2 from run number
65. (This was not the best way to do it... in the future, different
chips which come from one telescope on one night will be encoded
into the telescope name.)
4. The image extention
- If this is "com", then the image was one which was compressed using a
lossy wavelet compression and sent over the internet. If it is
"raw", then it is an uncleaned/unreduced frame. If it is something
else, then usually it means it's a cleaned image. The something else
is often "csg" for CTIO images. It is any number of things for
images from other telescopes. The lesson is, don't use the "com"
images if there is something else out there.
"csg" usually indicates an image which has been edgsurfaced.
Frequently "cln" means the image has not been.
5. .fts
- It's a FITS file. Because Bill Gates rules the world, we only get to
put three letters after the dot.
Other images in the database
If you perservere enough, eventually you are going to come across images
whose names are a whole lot longer than the specification listed above. If
you look closely, you will see that these are often concatenations of image
names such as above (without the ".fts"), with a .fts on the end. These are
usually subtractions. You don't have to worry about them; all of our IDL
software which uses the subtractions knows how to find them.
Last updated: 2000 January 5