Re: LF: First LF trans ecuatorial spots from FR5DH in WSPR2

[James Hollander <mrsocion@aol.com>]

RR Stefan.  FB on your 2011 & 2012 2200m achievements!

     Yes, re pre-sunrise involvement--the FR5DH receptions of EA5DOM 0230 & 0236z were about 25 and 19 minutes prior to FR5 sunrise 0255z (locally 6:55a.m. UTC+4).  Much appreciated your prop insights.

      Food for thought items:  Estimate of pre-SR geometry of MF E-region bulged downward at 5° tilt and then less as time went on.  http://njdtechnologies.net/041217/  .  There may be variation of the tilt value with latitude.  I’m at 35°N where my 2017 data was taken.  Reunion is 21°S, so Earth and E-region moves faster beneath the sun than where I am, and pre-SR E-region tilt was probably a little less than 5° max there.  SR at E-region altitude is pre-SR at ground level.

       EA5DOM LF path probably arrives roughly 45° NW at FR5DH while 6/30/19 SR heading is 65° NE at FR5DH.  The terminator is within 20° of parallel with a great circle (?) radio path.  The 3D geometry becomes complicated but calculable.  We can expect an SR enhancement, however, to include lateral skew off the bulging pre-SR LF E-region and combine with a "regular" 2200m ray direction as the rays descend into Reunion Is.  The pre-SR E-region bulge will probably have some texture, so more rays might also be involved.  At the long wavelength 2200m, the texture would need to be quite extended, however, compared to 630m.

       FR5DH 630m reception 2010-0140z in May, 2018, was midnight to wee hours, i.e., without involvement of pre-SR enhancement. http://njdtechnologies.net/052018/ 

       As to 6/30/19,  2200m pre-SR enhancement probably involved the last hop only, due to shallow tilt, but I'd need ray tracing/calc to check.  If chordal prop occurred over Africa, it likely was a spatially separate phenomenon.   Even though a certain account of last night’s 2200m prop may elude us, I see it as a combination of possible chordal hop over Africa augmented by pre-SR enhancement of the rays on a subsequent final hop.  And yes, what would be an accurate estimate of transmitted power density...

       Summer fun & wakeup experience, yes! TU & 73 Jim H  W5EST