On 09/16/2011 04:47 AM, HB-GRAL wrote:
> I provide a ESRI Shapefile on my server of the airports of
> ourairports.com database
> There is a column "type", and some airports have value "closed". All
> this data is in public domain, if someone wants to play around with it
> or want to check something.
Thanks, that's interesting. For some purposes, the ESRI files may
or not be the most useful or transparent representation; for some
purposes it may be more useful to look at
and other files as described at
The data from ourairports is in some ways more sophisticated than
from apt.dat. For example, it gives the elevation of *each end*
of each runway, rather than simply field elevation. In some parts
of the world this is valuable information for pilots. AFAICT the
ourairports data could be used to provide useful information for
airports that are missing from apt.dat ... maybe not ideal but
way better than nothing. Somebody could write a script to do the
translation ... or we could just read the ourairports files directly.
OTOH apt.dat has taxiway information for some airports, whereas
I don't know of any such information at ourairports.com. If I
have overlooked something, please let me know.
FWIW I have a prog that reads apt.dat and writes kml, which
can then be imported into your favorite GIS such as GRASS or
google-earth. The idea is to make it easy to compare apt.dat
to the ground truth.
I haven't taught it how to read ourairports databases, but
that wouldn't be hard.
Here is another way in which the ourairports database can be put to
very good use: It provides ISO region codes -- which apt.dat does
not. These codes provide the basis for a very good way of predicting
which runway numbers will have a leading zero. Compared to guessing
"always leading zero" or "never leading zero" this reduces the error
rate by at least two orders of magnitude. Doing a join on the two
databases is easy.
As for the reliability, comparing ourairports to apt.dat on fields
that they both provide, it appears we have a Venn diagram with all
-- Airports where they are both correct.
-- Airports where apt.dat is right and ourairports is wrong.
-- Vice versa.
-- Airports where they are both wrong in different ways.
-- Last but not best, airports where they are both wrong in
the same way, so we don't learn anything by cross-checking.
For example, there are some airports that were wiped out and
replaced with condos many years ago, but still show up in
FWIW here are the fields in some of the ourairports files: