(no subject)

["Brent K. Lemons" <bklemons swbell net>]

John,

Sorry about the confusion!  With the move I had to change from a cable modem to
dsl, unfortunately Southwestern Bell takes a month to install.  I tried
replying to this message once, but the listserv didn't let my yahoo address
through.

I use the 56-day NAS database from the FAA.  It does not have terrain data, but
I have obtained that data in the past from the USGS.

GRIB is a gridded forecast available from the NWS.  The data is available at
several flight levels and included temperature, relative humidity, wind
direction and speed, as well as a few things that would currently be irrelevant
to us.  There are several different GRIB products available.  There is an
aviation model that runs every 12 hours (0000UTC and 1200UTC).  It is a very
high resolution forecast and has forecasts for every six hours up to 48 hours. 
The model I'm working with for fplan is called the RUC (Rapid Update Cycle)
model.  It is run every three hours.  Because it runs every three hours it has
to crunch numbers more quickly and it has a resolution of every 40 or 20km.  I
am currently about 60% along on this effort.

I'll notify everyone as soon as I have a workable version ready for the use of
the RUC model.

brent



Hi Brent,

Do you use the National Airspace Database from the FAA or ARINC
424-13 format data from a vendor like Jeppesen? Certainly the NASD
database has most of what you want (except for maybe terrain heights),
and it's very affordable for your average private pilot.

It's too bad, but it looks as if NOAA's digital aviation
sectionals will be similar to the USGS "Digital Raster Graphics"
product, which are nothing more than a raster scan of the paper maps.
Not too useful...

>  
>I think I have two items I can contribute.  First the interface
>you desire to have the ability to select waypoints by clicking
>on them.  I have basically already done this, though it was in
>Motif and Xlibs, but I don't think it would be too difficult to
>port my routines to gtk.

My comments about that feature might be a little misleading. I
don't think the software side of it is all that difficult, it's more
related to the data issues I quizzed you about above.

I've considered writing the GUI in python, using the py-gtk,
py-gnome bindings (whatever language is used, I'm sold on the 
gnome canvas for any cartography stuff). Any of the scripting
languages with gtk, gnome bindings would work, the idea would be
to try and cut development time. Libglade is another tool that
could help here...

>
>Secondly I know how to parse and use GRIB wind forecasts from
>the NWS.  Rather than a command line option for expected
>wind direction, fplan could use the good stuff that the big boys
>use.
>  

This item was near the top of my TODO list. I was planning to add a
variant of the wind command that admits a tabular specification as a
function of altitude. Most private pilots will feel most comfortable
with the usual forecasts provided by flight service.

For example; todays forecast for SAN...

VALID 280000Z   FOR USE 2100-0600Z. TEMPS NEG ABV 24000
FT  3000    6000   9000    12000   18000   24000  30000  34000  39000
SAN 2607 1707+20 1509+13 1409+07 1413-08 1620-20 173335 174045 164655

corresponding "wind" command...

wind 3000 260 7
6000 170 7
9000 150 9
12000 140 9
18000 140 13;

This would be general enough to allow different data sources as well.
I'm not familiar with the NWS GRIB forecasts, where can these be found?

I need to run for now, I will post again to address some of the other
issues you mentioned, such as a web interface for fplan (perhaps add
XML format input, output?)

Best Regards, John

-- 
___|___ | John C. Peterson, KD6EKQ | Try Linux for Intel x86, because all
-(*)-  | mailto:jcp eskimo com    | of the best things in life are free!
o/ \o  | San Diego, CA  U.S.A     | See http://www.linux.org/ for info

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