GL - A Distance / Bearing Program
for Palm Handheld Organizers
A useful tool for microwave communication is a program that can calculate the aiming-bearing and the distance between two locations. The PC program BD is easily available and widely used. I have written a new program, GL. This program runs on the small, portable Palm handhelds, or any equivalent that uses the Palm OS.
Several years ago I wrote a program for MS DOS-based PCs that I named GLKEY. It computed distance and bearings between two points and also had a CW keyer. I used it during the ARRL 10 GHz contests and found it quite useful.
I knew there were free tools for writing programs for the Palm OS, and began investigating them. After much web surfing, I found all the pieces to set up GNU development tools for the Palm from the Free Software Foundation, Inc. The Palm website now even has a section where you can download these tools. It includes a fully functional C compiler and I already knew how to write in C. I decided that a worthwhile project might be to make a version of my GLKEY program that can run on the Palm. After many hours of studying, coding and testing – spread out over about a year – I finally got a program that I like. I think it may be useful to the microwave ham community, and I plan to make it available for free to anyone who wants it.
A Palm Handheld Running GL
GL Features
Here is a list of the basic features of the program.
- Quick entry of Base and Target locations that accepts multiple formats.
- Accurate calculation of bearing and distance using standard ellipsoid models of the earth.
- Display of distances both between two exact points and between the centers of the two Maidenhead grids. (The latter is used for contest scoring.)
- Ability to load a location from previously saved lists of locations.
- The location lists are done as MemoPad text files so they can be created easily, either in MemoPad on the Palm or by importing text files into MemoPad on the Desktop.
- The program retains its status after other programs are run or the Palm is powered off.
The program has a GNU license and is available for no charge.
Download it
The latest version of the program is 1.10. It was released
on July 14, 2002.
Read the files Newstuff.txt and history.txt in either of
the program zip files to find what has changed.
Click here for a zipped MS Word document about the program
-- GLpaper.zip
(The document version does not describe the changes
between ver 1.02 and 1.10.)
And here is the same document in PDF form -- GLpaper.pdf
Click here to download the program -- GL110prg.ZIP
Click here for the program with source code -- GL110src.ZIP
*** The program requires MathLib also be installed on the Palm.
Click here for MathLib -- mathlib.zip