[CQ-Contest] IARU log checking report

[Michael Keane, K1MK]

Yeah, this topic aperiodically resurfaces as it is confusing. Bottom 
line is  what we refer to as ITU zones in amateur radio, are not the 
official ITU HFBC CIRAF zones.

The history behind this is that the official ITU zones (formally the ITU 
HFBC CIRAF zones) as found in the ITU Radio Regulations and the FCC 
Rules, are a set of zones originally defined at the 1947/1948 ITU HF 
Broadcasting Conference held in Mexico City. These zones are used in 
defining reception target areas for scheduling and frequency 
coordination in the HF Broadcasting (HFBC) service. They are known as 
CIRAF zones because CIRAF is the acronym for Conferencia Internacional 
de Radiodifusión por Altas Frecuencias... Spanish for International 
Conference on HF Broadcasting.

The zones specified at that Mexico City conference are a set of 
latitude/longitude vertices which are connected by rhumb lines i.e., 
straight lines on a Mercator projection. The boundaries of these CIRAF 
zones do not follow any national borders (except by serendipity). That 
makes sense given that the purpose for defining these zones was to 
create a coarse grid for calculating HF coverage plots using propagation 
prediction programs of the day, the predecessors of what evolved to 
become VOACAP, etc.

AFAIK, the amateur radio version of ITU zones came about when someone 
grafted the ITU HFBC CIRAF zones onto an amateur radio context. (Anyone 
know who first did this and when? Was it the IARU? Was it the Radio 
Amateur Callbook?) In the process of doing that, a number of changes 
were made. The biggest changes being that the amateur radio version of 
ITU zones have boundaries that are in many cases coincident with 
national, political borders, but certainly not in all cases.

The IARU Region 1 HF Managers Handbook contains in its Chapter 10.10 a 
table entitled "ITU Zones, when used in the amateur service". That is 
probably the best way to think of these zones as they have relatively 
little in common with the official ITU definitions except the name.

The amateur radio modified set of the "ITU zone" definitions shown in 
the R1 HF Managers Handbook, the ARRL Opearting Manual and elsewhere has 
been what's been used in the IARU HF Championship and the preceding IARU 
Radiosport Championship since the first running of the latter contest in 
1977.

Given that it's quite easy to confuse "ITU zones" (ITU HFBC CIRAF zones) 
with "ITU Zones" (ITU Zones as adapted for use by amateur radio 
operators in contests) one can expect this topic to resurface again in 
the future :-)

73,
Mike K1MK

On 6/5/2010 9:46 PM, David Gilbert wrote:
>
> It appears that EI8IC waded through that swamp several years ago, with
> the general conclusion that ITU zones for ham radio purposes are
> whatever the contest sponsor says they are.
>
> http://lists.contesting.com/_cq-contest/2002-09/msg00130.html
>
> 73,
> Dave   AB7E
>
>
>
> On 6/5/2010 3:22 PM, Doug Grant wrote:
>> I got curious, and went to the ITU site to confirm Joe's statement
>> that part of Wisconsin is in Zone 7 instead of 8.
>>
>> The Official ITU CIRAF Zone map can be found here:
>>
>> http://www.itu.int/ITU-R/terrestrial/broadcast/hf/refdata/maps/index.html
>>
>> He's right.
>>
>> A quick look shows that the boundaries do not fall cleanly on
>> call-area, state or even national borders. There are lots of
>> part-of-Wisconsin-in-Zone-7-not-8 boundary cases. Half of Belize is in
>> Zone 10, half in 11. Part of Maine (I think W5WMU/1's QTH is in that
>> part) is in Zone 9 (generally all Zone 9s are assumed to be Canada).
>> Parts of Washington State are in Zone 2. The U.S.-Mexico border
>> wanders back and forth across the line, so some U.S. guys are really
>> in Zone 10, and some XEs are in zone 7.
>>
>> In fact, the resolution of the official map is not particularly great,
>> so it may be tough for a lot of people to figure out what zone they
>> are really in.
>>
>> Seems to me that the ITU CIRAF zones were drawn with straight lines in
>> an attempt to as closely as possible match assorted political
>> boundaries. The intent was probably to match them exactly, but there's
>> no obvious record I could find on the ITU site that said that. I found
>> a text document that defines the (I think) the corners and centers of
>> various quadrants within each zone for the purposes of monitoring
>> signal strength of HF broadcast stations here:
>>
>> http://www.itu.int/ITU-R/terrestrial/broadcast/hf/refdata/reftables/ciraf.txt
>>
>> Kind of a drag that country/state boundaries don't fall cleanly on
>> latitude/longitude lines, eh?
>>
>> So you can give out whatever zone you can reasonably assume the ITU
>> wants you in...as long as you send the same zone the whole contest.
>>
>> And good luck to the log checkers!
>>
>> 73,
>>
>> Doug K1DG