Snapshot of US National Airspace Data CD-ROM

["John C. Peterson" <jaypee@netcom.com>]

FWIW,

   I received my copy of the (US) National Airspace Data CD-ROM last
week. For those that were interested in it, here is a little snapshot
of what is on it...

   First off, the $36 cost included shipping by FedEx Overnight, so
delivery is timely. Looks like they come out about 3 weeks ahead of
the time the data is considered effective. (The CD was stamped with
1 Jan, 2000 as the "effective date"). Curiously, I got another CD on
Monday of this week to correct an error in one of the files, not bad!

   The CD does indeed contain all the data files they describe on
their web site. They are all simple ASCII files, with fixed length
records. Documentation is included describing each of the files.
There are no "comma delimited" format files on the CD-ROM, like
those that were available for free download at one time.

   I hope to have the avdbtools software fixed sometime after the
holidays and get the US database files on the fplan web site updated.
(It will also contain the new year 2000 IGRF and WMM coefficents for
the magnetic variation model).  I have looked everything over, and it
doesn't look like the changes required are very radical, but I really
won't have much free time until after the holiday crush.

   To keep the work involved to the minimum, my plan is to write new
awk scripts to generate intermediate files with "colon separated"
fields, similar to the old "comma separated" ones. I looked at the
awk scripts that were used to generate the old comma separated files
and quickly concluded that "," is a bad choice for a field separator.
Any "," characters that actually appeared in the data were being
silently deleted! Not a good idea if you can avoid it. By using colon
for a separator, you can simply re map any that actually appear in
the data files to a semicolon using sed, without really changing
anything (the record length in particular). It appears they are only
used for punctuation in remarks, so no big deal.  I'll probably only
extract the data fields required by the fplan format files to keep
things simple.  However, if anyone has an interest in using these
scripts for other purposes, let me know and I can add additional data
fields.

Seasons Greetings, John

-- 
 ___|___  | John C. Peterson, KD6EKQ | Micro$oft free since 1987... I support
  -(*)-   | mailto:jaypee@netcom.com | the boycott of all Micro$oft products!
  o/ \o   | San Diego, CA   U.S.A    | See http://www.linux.org/ for info
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