Program SKYTRIG - SKYWAVE TRIGONOMETRY
With an input of elevation angle, layer height and critical frequency, the program calculates skywave path distance, groundpath distance, spreading (dispersion) loss, field strength from a 100 watt transmitter, and the MUF.
The program can be used for guidance on the low MUF's and the geometry of near vertical incidence radio paths over short distance groundpaths.
Elevation angle is NOT the angle at which an antenna radiates the strongest signal. It is the angle of the path taken by the radio wave between two places on the Earth's surface and is nothing to do with an antenna.
The program notes provide some elementary information on the heights and behaviour of the various ionospheric layers in sunlight and in darkness. Also on factors which affect received field strength such as operating frequency being greater than MUF.
Download in a few seconds program SKYTRIG from website below. Filesize = 42 kilo-bytes. Run immediately. Or you can open/run it without downloading.