Sporadic-E propagation at 144 MHz and higher is much less frequent than at 50 MHz. We know that when short-skip exists on 50 MHz, the likelihood of sporadic-E propagation existing at 144 MHz is greater. The question is: "How short must skip be for the 2-meter band to open up and where will the band be open to?" The program SE-PROP developed from curiosity in being able to explore the concepts contained in Emil Pocock's (W3EP) article "Sporadic-E Propagation at VHF: A Review of Progress and Prospects", QST, April 1988. The lastest version of SE-PROP is version 1.0.1.
Another mode of long-distance propagation at 144 MHz is by scatter from field-aligned irregularities (FAI). Thomas Kneisel's (K4GFG) article "Ionospheric Scatter By Field-Aligned Irregularities at 144 MHz", QST, January 1982 discusses FAI. The program FLD-ALGN was developed to explore field-aligned propagation such as auroral scatter and FAI.
The IC8FAX FAI web page contains an excellent review of FAI scatter propagation.
FAI scatter is associated with intense sporadic-E ionization. An eariler program, ES-PROP, was upgraded to include the FAI aspects of FLD-ALGN. With this enhancement, ES-PROP was renamed SE-PROP.
SE-PROP.ZIP ver. 1.0.1 (84.7 kb) (November 1999 version)
Sporadic-E propagation analysis with FAI scatter evaluation
FLDALGN.ZIP ver. 1.12 (89.0 kb) (17 June 2000)
Field-Aligned Dependant Propagation: A Program for the Assessment of E-layer Field-Aligned Propagation
Map files for use with SE-PROP and FLD-ALGN
Additional map files.
A Windows version is available. SE-PROP for Windows is a 32-bit program and will require Windows 9x. SE-PROP for Windows is being distributed as a unsupported program.
(Un-zip the SEP-WIN archive into a suitable folder and run SETUP.EXE to install the program.)
The author has not been able to verify the utility of these programs. User feedback pertaining to actual propagation conditions and whether or not these programs provided correct analysis is requested. Comments can be sent to:
Last revised 02 JAN 2010