[SADXA] July SADXA Presentation Abstract on Tucson/Heard Island Gray-Lilne Propagation Study

Mon Jul 18 11:05:17 EDT 2016

Ah yes, Convention time. The universal
cure for Insomnia !!

HI HI

73, Dick, W1KSZ

On Sun, Jul 17, 2016 at 6:35 PM, W7EXG (Bill) <W7EXG at q.com> wrote:

> Dick,
>
> Yes, perhaps not the best of time to present, in view of vacation travel,
> schedules, and RNC convention.
>
> 73s, Bill W7EXG
>
> -----Original Message-----
> From: SADXA [mailto:sadxa-bounces at mailman.qth.net] On Behalf Of Richard
> Solomon
> Sent: Thursday, July 14, 2016 3:29 PM
> To: Southern AZ DX Association E-Mail Reflector
> Subject: Re: [SADXA] July SADXA Presentation Abstract on Tucson/Heard
> Island
> Gray-Lilne Propagation Study
>
> This sounds very interesting,
> I hope everyone gets a chance to
> attend.
> I am looking forward to it.
>
> 73, Dick, W1KSZ
>
> On Tue, Jul 12, 2016 at 9:37 PM, W7EXG (Bill) <W7EXG at q.com> wrote:
>
> >
> > To: SADXA Members
> > FROM: Bill W7EXG
> > RE: Tucson/Heard-Island Gray-line study Presentation - Part 1
> >
> > Over the past 3 Months, I have studied extensively Gray-line Propagation,
> > and especially as it relates to the Tucson / Heard Island Observations.
> >
> > Unfortunately, this is NOT a LOW BAND Gray-line discussion, since I am
> > unaware of any Tucson-Heard 160m or 80m signal data to study. Perhaps the
> > mire absence of low band data may be of value. However, I am convinced
> that
> > many of the lessons learned on the observed 40m, 30m, 20m, and 17m
> > Gray-line
> > signals, can be applied to the low band cases.
> >
> > I plan to present part 1 of this study in our July Meeting.
> >
> > PRESENTATION REPORT:
> > Gray-line Propagation: Lessons Learned from the Tucson / Heard-Island
> > Experience -- PART 1 of 2 Parts
> >
> > WHEN: July 21, 2016
> > WHERE: SADXA Meeting
> > DURATION: ~ 45 min / 15 min Q&A
> >
> > WHO: Bill Davis -- Licensed as W7EXG in 1956
> > Bill is an Electrical Engineer, having retired from Motorola - after
> > working
> > 30 years, as an Analog IC Design Engineer / Manager. Bill was a Senior
> > Member of the Motorola's Technical Staff.
> >
> > ABSTRACT - PART 1
> >
> >         This study was motivated by Gray-line Observations of signals
> > between Tucson and the Heard-Island DXpedition, by several SADXA members.
> > These Observations appeared to challenge or modify both past and current
> > definitions and descriptions of Gray-Line Propagation.
> >         After a brief review of such definitions and descriptions, an
> > observed 40m Long Signal Path is shown as an interesting example of
> oddity.
> > Starting at night 2500 mi from the Sunset Terminator, this signal
> traveled
> > 3600 mi in DARK, then about 10,200 miles in daylight, 1700 mi and 2.5
> hours
> > from the Sunrise Terminator. This signal path defied some Gray-line
> > definitions such as "Near or Along the Edge of Terminator", or "requires
> > Simultaneous Sunrise and Sunset"...etc.
> >         Twenty Signal Observations were gathered by 6 members of the
> SADXA
> > group, and were compiled as AM / PM, Long Path / Short Path, Band, and
> > Date.
> > Six example Timelines are shown for both AM and PM Observations. The
> Impact
> > of the Kp Solar Indices is discussed, during these observations.
> > Eleven questions were raised regarding these observations, such as WHY:
> > ALL
> > propagation was AFTER Sunrise/Sunset?; NO AM Short Path or 40m Short Path
> > propagation?; 40m Long Path observed before 30m long path? Or, how does a
> > 40m signal travel over 10,000 mi in the DAY regions, 1700 mi from sunrise
> > terminator?
> >         A Review of Day/Night Ionospheric Layers is discussed, including
> > Day/Night Band Use and Limitations. The concepts and importance of EMUF
> and
> > MUF on Gray-line propagation are also discussed.
> > A review of electron charge distribution for each layer is shown over
> > Day/Night Period, including Sunrise and Sunset.
> > The important of the EMUF at Sunrise / Sunset is shown to be a critical
> > factor in defining Gray-line geographic widths, using a mid band signal
> as
> > example.
> >         EMUF is defined in terms of the Critical E Frequency (foE).
> > Ionsosndes (Vertical Soundings) foE Data is shown at Sunrise, from a Mid
> > Latitude ionosonses Observatory. This foE data supports and explains the
> > 40m
> > Long Path propagation cited above. The E-Layer electron density and
> > Rise/Decay time of foE is considered critical in defining Low/Mid band
> > Gary-line geographic width and propagation. The foE data also
> demonstrates
> > ionization in Twilight region, prior to Sunrise.
> >         MUF is defined in terms of the Critical F Frequency (foF2). Using
> > foF2 Data, World Color (MUF) Maps are shown for specific Tucson-Heard
> > Propagation dates, and times. Long or Short Signal Paths are superimposed
> > on
> > these MUF maps as a function of time,  which explains the observed
> timeline
> > delays and durations, as well as the viability of Long or Short Paths for
> > AM
> > and PM propagation.
> >         Finally, the 11 questions raised by the Tucson-Heard Observation
> > data are reviewed and answered based on the preceding discussion.
> >
> > Part 2 presentation is planned, during September SADXA meeting. There is
> > actually much more to say, such as ionization in the DARK region at
> > Sunrise,
> > effects of E and D-Absorption, Solar Indices effects, Band dependant
> > Propagation Corridors, and Daily, Seasonal and Annual Angular World
> > Coverage... etc.
> >
> > Best 73s,
> >
> > Bill W7EXG
> >
> > ______________________________________________________________
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> >
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