[CQ-Contest] contests and participation on air

[David Gilbert]

Great point.  IONCAP and it's derivatives VOACAP and REC533 were NEVER 
meant to represent anything other than a generalized propagation 
prediction using monthly average data.  Updating propagation predictions 
with hourly SSNs and K-indices is silly, and the documentation 
associated with IONCAP/VOCAP/REC533 specifically warns against it.  
Those hourly updates may be fun to watch, but they have no greater 
validity than the average monthly history behind them.

Good engineering practice says that we should never pretend we have 
greater resolution in our calculated results than the resolution of the 
data that went into them.  Dividing 90.0 by 47.0 might be 1.9, but 
dividing 90 by 47 is only 2 (filler added to relocate the period for 
clarity).  In this case, the difference between average monthly baseline 
data and the interpolation to hourly usage is unjustified to the degree 
of three orders of magnitude.

73,
Dave   AB7E


On 7/22/2013 2:47 PM, Rick Kiessig wrote:
> 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.
>
> http://www.voacap.com/itshfbc-help/rec533-general.html
>
> 73, Rick ZL2HAM
>
>
> -----Original Message-----
> 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 ...
>
> 73,
> Dave   AB7E
>
>
> 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
>> matrix
>>
>> 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
>>