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