Making the 2MASS Point Source Catalog Usable

Download all of the gzipped files containing the catalog from ftp.ipac.caltech.edu in the /pub/2mass/allsky directory. There will be a total of 42,672,321,835 bytes in 92 files. Files starting with psc_a cover the southern hemisphere. Those starting with psc_b cover the north.
```
   $ ftp ftp.ipac.caltech.edu
   Name (ftp.ipac.caltech.edu:user): anonymous
   331 Guest login ok, send your complete e-mail address as password.
   Password: your email address
   > cd /pub/2mass/allsky
   > prompt
   > bin
   > mget psc_*.gz
    . . .
   > quit
```
Modify tmcat.c to put the 2MASS catalog structure where you want it to be by changing the value of the variable "root", and compile the program. It is self-contained C.
gzcat all of the compressed files through the program tmcat to produce 180 directories, each containing sources from 1 degree of declination. They are named from 000-179 for their angular south polar distance (SPD) in degrees), In each of these directories there are 10 RA-sorted files named t000[0-9].cat. The 1800 files contain a total of 32,518,275,633 bytes of data.
```
	gzcat psc_*.gz | tmcat
```
A file called resort contains all those files where a single object was read out of RA order. You could only sort the files in this file, but there might be some cases with multiple sequential files out of order that would have been missed, so it is recommended that all files be resorted.
List all of the resulting files.
```
     ls [root]/*/* > filelist
```
Run the simple nawk script tmcsort to RA-sort all of the catalog files.
```
    tmcsort filelist
```
In libwcs/tmcread.c, change tmcapath to value of "root".
Remake WCSTools