rje@cae780.UUCP (Bob Evans) (09/18/85)
I would like to thank the person who posted the great circle navigation
program. As a result of the posting I tried the program, liked it, and
started creating a database for use with the program. I have created a VOR
file that contains all of the VORs for California, Nevada and Oregon. I have
also created an AIRPORT file that contains the tower controlled airports
for the same three states. I am working on an AIRPORT file that contains the
non-controlled airports, but won't have that finished for a week or so ...
If there is interest, I will post that file also.
As to using the program I have found only two problems -
1. Waypoints are not calculated to form a 90 angle between the route
of flight and the radial. I don't think that is a big problem, but
makes use of sequential VORs somewhat difficult as the program will
often pick waypoints that are quite close together.
2. When using VORs that are not between the origin airport and the
destination airport, the program does not compute a waypoint at the
airports from the first and last VORs. Instead, you will be routed
away from the correct line of flight. An example of this follows.
Palo Alto (Palo Alto)
PAO altitude: 5 feet
rvor WP1 freq: 113.9
*** L Oakland FSS ***
wp OSI R-163.0 / 4.9
PAO to WP1
Magnetic: 204
Distance: 12.0 NM
(true course 221, Total distance 12.0)
rvor WP2 freq: 116.0
*** H Stockton FSS tweb ***
wp SCK R-343.0 / 28.0
WP1 to WP2
Magnetic: 025
Distance: 79.3 NM
(true course 042, Total distance 91.4)
rvor WP3 freq: 114.8
*** H Sacramento FSS ***
wp LIN R-343.0 / 22.3
WP2 to WP3
Magnetic: 025
Distance: 11.7 NM
(true course 042, Total distance 103.1)
rvor WP4 freq: 115.5
*** L Sacramento FSS tweb ***
wp HNW R-163.0 / 3.5
WP3 to WP4
Magnetic: 025
Distance: 17.9 NM
(true course 042, Total distance 121.0)
rvor WP5 freq: 117.9
*** H Reno FSS tweb ***
wp RNO R-342.0 / 3.7
WP4 to WP5
Magnetic: 025
Distance: 75.3 NM
(true course 042, Total distance 196.3)
WP5 to RNO
Magnetic: 205
Distance: 7.7 NM
(true course 223, Total distance 204.0)
Cannon Int (Reno)
RNO altitude: 4412 feet
I haven't looked at the code to see if this can be remedied.
Have Fun,
Bob Evans
FROM: Robert J. Evans, CAE Systems Division of Tektronix, Inc.
UUCP: tektronix!teklds!cae780!rje
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USNAIL: 1333 Bordeaux Drive, Sunnyvale, CA 94089 [until we move ... soon]
AT&T: (408)745-1440 [until we move .. soon]rje@cae780.UUCP (Bob Evans) (09/20/85)
I have finished the file containing the non-controlled airports for
California, Oregon, and Nevada. The file is posted to net.sources.
I have examined the source code for the program and have modified it
to produce waypoints that are 90 degrees from the flight path to the VOR.
This makes much better use of the VORs. Alas, the program does not yet
understand that DME is _slant_ range. In order for this to work I will
have to add VOR elevation to the VOR file, and add some more code to the
program. If I'm lucky (meaning my better half doesn't notice how much time
I'm spending at the keyboard) I could have this done in 4 or 5 days ...
I will post the new VOR file and new source to net.sources then.
I have looked at translating this to TurboPascal. Shouldn't be too
hard. If there is any interest I will also post this to net.sources when
I get it done.
BTW, in order for slant range to work, the program will also need altitude
info for each flight leg. I'm adding that to the code as well ... ....
As soon as the code is checked out (against a ProStar) I'll post the sources.
FLASH - the latest AOPA newsletter says that NOS (national ocean survey)
is considering selling
a database of navigation information in machine readable form. Proposed
formats are 5 1/4 floppy, nine track tape and paper (?).
Maybe it will be cheap enough that we can all afford it !
Bob
FROM: Robert J. Evans, CAE Systems Division of Tektronix, Inc.
UUCP: tektronix!teklds!cae780!rje
{ihnp4, decvax!decwrl}!amdcad!cae780!rje
{nsc, hplabs, resonex, qubix, leadsv}!cae780!rje
USNAIL: 1333 Bordeaux Drive, Sunnyvale, CA 94089 [until we move ... soon]
AT&T: (408)745-1440 [until we move .. soon]