[CQ-Contest] contests and participation on air
kiessig at gmail.com
Mon Jul 22 17:47:51 EDT 2013
It's also worth mentioning that REC533, upon which Zoneprop is built, is intended to be used to estimate long-term averages, not to make short-term predictions. Using short-term Kp and running frequent updates doesn't change the nature of the underlying model.
73, Rick ZL2HAM
From: CQ-Contest [mailto:cq-contest-bounces at contesting.com] On Behalf Of David Gilbert
Sent: Tuesday, July 23, 2013 5:25 AM
To: cq-contest at contesting.com
Subject: Re: [CQ-Contest] contests and participation on air
I'm a subscriber to the VOACAP mailing list, and here's a recent (just a few weeks ago) comment from George Lane, one of the key original members of the IONCAP development team.
"Beware of using CCIR Data Base D or D-1, etc. When I was on the Working Party 6 of the CCIR, I discovered that the Data Base D had been ‘normalized’ to remove the antenna gain data based on takeoff and arrival angles dependent totally on path distance! This totally corrupted the data base. This is one reason I totally suspect REC.
533. Further when I ran REC 533 back in 1996 when I still worked at VOA using Greg Hand’s version, I found that signal power could increase as one went from 1 hop to 2 hop and 3 hop distances. For some reason I just don’t believe the Ionosphere works as an amplifier until you get near the antipodal location. Perhaps, that has been fixed, I hope."
For what it may be worth ...
On 7/22/2013 7:01 AM, VE5ZX wrote:
> One could also check Zoneprop ( http://www.radiosport.ca/zoneprop/ ).
> ZoneProp uses a widely accepted propagation engine to determine the
> band on which a contestant in one CQ DX zone is likely to be able to
> contact a contestant in another CQ DX zone taking into account the
> current geomagnetic activity.
> ZoneProp produces a 40 zone by 40 zone matrix that is updated hourly
> at approximately 20 minutes past the hour. The intersection between a
> row and column gives the band on which a contestant in the zone
> represented by the row is mostly likely able to contact an contestant
> in the zone represented by the column. The zone numbers in the left
> hand column are clickable. Once clicked the information for that zone
> is displayed in isolation above a map of CQ DX zones. The pages are
> refreshed every 10 minutes in order to capture hourly updates of the
> Technical details
> At the heart of the ZoneProp program is REC533, an NTIA/ITS rendering
> of the ITU-R P.533 package. It was chosen following many years of
> NCDXF Beacon Chain monitoring results from various sources, and
> comparisons with actual ionosonde data. As with any propagation
> predictions program the input parameters require careful consideration
> and calibration. The results from the above mentioned studies
> contributed to the monthly publication of various predictions tables,
> in the RSGB’s - RadCom and the Italian - Radio Rivista magazines to
> name but two. This continuing experience has been applied to the
> production of ZoneProp.
> The web output of the model first queries the WWW for the relevant SSN
> and an up-to-date K-index figure. These are used to build an input
> file that is then passed to the prediction program for the required
> results, FOT (Frequence Optimum de Travail), or Optimum Working
> Frequency. Unlike the vast majority of predictions programs the
> K-index is utilized to adjust the FOT as it rises and falls. The
> International Reference Ionosphere (IRI) and actual ionosonde outputs
> were used to determine the variations in FOT.
> The other input variances are the co-ordinates for the zones, which
> are the CQ-WW zones. The zone co-ordinates were chosen to be either in
> the center of the zone or at the highest population density that is
> nearest to the center. The correct method of reading the matrix is to
> use the left hand list of zones as the starting point and then to take
> the destination zone from along the top. This will show the correct
> FOT for the time of day, propagation is not always reciprocal. An
> example of this is on an East/West path when one end of the path is in
> darkness and the other in daylight. During the morning between W1 and
> W6, is a good example.
> Syl -VE5ZX
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