Re: What's the best TLE file?
Neil Clifford (n.clifford1@physics.oxford.ac.uk)
Mon, 30 Oct 1995 10:42:50 +0000 (GMT)
Jeff Hunt scribbles:
|>These files are compressed in the gzip format. I seem to recall Neil said if
|>you didn't want to receive them compressed you can decompress them on the fly
|>by not including the *.Z suffix. The disadvantage is that it is going to
|>take about 3 times as long to receive them uncompressed.
I'm running the wu-ftpd for the ftp archive so you can specify whther or
not you wish to have a (UNIX) compressed file or (GNU) gzipped file by
adding the appropriate suffix (.Z, .gz). Likewise you can uncompress by
getting the filename but dropping the suffix. I'll toy with the PD
version of zip too if that makes things easier for IBM PC owners.
|>The next site is ftp://kilroy.jpl.nasa.gov/pub/space/elements/molczan
|>(which Neil mirrors). In that subdirectory you can find a utility program
|>called gzip121.zip which contains the gzip.exe program for PC's to
|>decompress *.Z files. Using it saves a lot of transmission time. This site
|>may also allow decompressing on the fly, I don't recall for sure.
Look out for the 'wu-ftpd' string when you log in - this provides the
facility but of course the site admin may not have enabled it (I think
it is enabled at kilroy though). Gzip is also at
ftp://ftp.physics.ox.ac.uk/pub/ibmpc/utils/gzip.exe
|>For myself, I like Allen Thomson's (sp?) +600K compressed file found at
|>ftp://kilroy.jpl.nasa.gov/pub/space/elements/satelem compressed in Z. If
|>you decide to uncompress that on the fly bring a lunch! However I don't
|>recall that Neil mirrors that file. Don't forget to shift to binary mode.
Mirrored under
ftp://ftp.physics.ox.ac.uk/pub/sat/mirrors
where you'll find sub-directories for the Molczan, Thomson and Kelso tle
files (under molc, elem, afit). For your convenience I have all the
Kelso files, plus the latest Molczan and Thomson (all flat, uncompressed
ASCII) under the directory
ftp://ftp.physics.ox.ac.uk/pub/sat/elements
so you could grab them all in one go from there.
--
Neil Clifford <n.clifford@physics.oxford.ac.uk>
http://www.physics.ox.ac.uk/sat/satintro.html