The great-circle mapping program
This program allows both great-circle (polar) and rectangular projections of the world. The great-circle map is centered
on any specified latitude and longitude (the "home" location). The rectangular projection is shown with the home
longitude in the middle of the screen.
The extensive database of cities and countries was upgraded by Vince Grgic, S52CC, and thanks are extended to him for his
considerable effort! If you have modified that database yourself, be sure to archive it and add your changes to Vince's
version. Better yet, tell either of us about any changes so they may be incorporated into the program.
Current version of Pizza is 2.14
; size of this significant upgrade is 2.7 MB
- The home location can be specified by either a direct entry into a textbox or by using a pulldown list of over 3200
sites around the world.
- Similarly, a target location can be specified directly, by using another pulldown list or by entry of the
Maidenhead grid data into a textbox.
- The home and/or target locations may also be entered by selecting the rectangular projection and left-clicking on a
location to instantly specify a home location, or right-clicking on a location to instantly specify a new target
- The target location may be entered on either the polar or rectangular projection by clicking on List Calls and then
selecting a prefix.
- The current sun location along with the terminator are (optionally) shown on both projections. An Offset input
allows correction for daylight savings or half-hour time zone correction.
- The path from the home location to the target location is shown on both the polar plot and the rectangular
- Text data files for an antenna pattern can be overlaid onto both the polar and the rectangular plots; pattern size
is adjustable. "Rings" showing gain referred to the azimuth of maximum transmission and 3, 6 and 12 dB below that point
can be toggled on and off.
- The size of the plot in terms of kilometers can be stepped by pressing the "Closer" or "Farther" buttons.
- A compass with lines at 10 degree intervals can be overlaid on the display. This can be toggled on and off using
the "Compass" button.
- A set of rings showing distance in 1000 km intervals can be overlaid on the display. This too can be toggled, by
using the "Distance" button.
- The resolution of the on-screen plots can be adjusted over a wide range. This allows quick screen update even on a
slow computer, or higher-quality presentations at the expense of an increase in plotting time. The output from the
printer is always at the highest resolution.
- The output to the printer is from a separate routine which closely duplicates the output as seen on the screen, but
of course without pixelation. To send a plot (polar or rectangular) to the default printer just press the "Print"
- If the home location is within the contiguous United States, and if the size is set so that the map covers mostly
those states, then the map shows the state boundaries as well.
- On exiting the program the current parameters are stored for an easy restart.
- The plotting routines really need a fast computer. Using a fast computer allows good screen resolution within a
reasonable time frame. Slow computers take longer to re-plot the screen for a given resolution. Plotting resolution is
adjustable over a wide range.