Santa Barbara Amateur Radio Club 4th U.S. ARDF Championships

2004 US ARDF Championships Course Notes

ARDF consists of four elements; direction finding skills, orienteering skills, physical condition, and suitable DF equipment. It is hard to rank these in terms of importance because strength in one area can help overcome weaknesses in other areas. My objective was to provide a venue where the skills of the competitors could be compared using any of the DF equipment expected to be present.

From the standpoint of course difficulty from hardest to easiest; I used M21, M19, D21, M40, D35, M50/D19, M60, D50 as my ideal ranking. Laying out nine courses with only five transmitters means that compromises need to be made. I was most concerned with the M21, M40, and M50 classes, and thus these were given preference when those compromises were made.

There are two classic layouts for ARDF courses, a domino five and a trapezoid (one at each corner plus one in the middle of the longer side.) The Vasquez Rocks layout was a domino five and Mt Pinos was a trapezoid layout.

The choice of venues was dictated by the available orienteering maps in the area. Both Vasquez Rocks and Mt Pinos have two of the very best maps available in Southern California. Vasquez Rocks for the 2M competition was a natural choice because of the reflections competitors would encounter. Mt Pinos is a great area for orienteering and as such, was the natural choice for the 80M event. Both venues were made public because of the number of competitors who already had experience orienteering in these areas. Both maps were both available in OCAD format, and had been field checked within the past 8 months. I decided to add the exclusion zones to the map rather than provide templates for the competitors to make their own. To my knowledge, this was the first ARDF event to have done that, and I will be interested in any comments about adding them to the maps in the future.

2M - Vasquez Rocks

This seemed like an ideal 2M venue because of the potential for reflections and the technical difficulty of orienteering. Because Vasquez Rocks is located in the high desert, I was very concerned about heat affecting the competition. Thus, I wanted the competition to begin as early as possible and to keep the climb to a reasonable level. When choices had to be made, they were made with respect reducing the time on the course. My goal was a 5 km M21 course with a 45 minute winning time by world class competitors.

The start and finish locations were dictated by access and the start/finish exclusion zones. The 400M finish zone is small enough that it could easily go in a number of places, but the 750M start zone could make a major cut into the interesting parts of the venue. The start zone selected had easy access for the people working the start, and only had about a 300M walk for the competitors. The finish zone at the group camp site fit in quite nicely with access and had minimal impact on the competition area.

In general, transmitter #3 is typically placed in the “middle” of the competition area with #2 and #4 furthest out. This leaves #1 and #5 near the start/finish to help round out the course.

#1 was placed just outside the start exclusion zone placed on the downside slope so that there would be some minor reflections from areas outside the park.

#2 was placed at an outside edge of the competition area with a hill between it and any other locations on the course.

#3 was placed in the middle of the park located so there would be both reflections and the need for route choice decisions.

#4 was place on the outside edge of the park such that there was no direct signal path to the eastern edge of the park, and to add length to the course.

#5 was located near the finish as an easy to find control that would add length to the course.

80M - Mt Pinos

This seemed an ideal 80M competition area that provided an opportunity to test out orienteering and physical shape. Trails are located throughout the area and it is easy to run cross country. My onl.y concern was that the altitude, ranging from about 7500 to 8500 feet, would make it difficult to compete for those people who had not trained this high. Our headquarters location in Gorman at about 4000 feet was an effort to help the competitors get accustomed to the higher altitude.

The start location was about a 200M walk from the upper parking lot. The finish location was placed at McGill campground since that provided easy access and we could reserve a campground for both the finish and medical areas.

My goal was to provide a course about 7 km in length with most of the running going downhill to reduce the effects that the higher altitude might have. To provide an orienteering challenge, I placed controls on both sides of a fairly deep ravine with the expectation that competitors would use their orienteering skills to find an appropriate place to contour through the area. I expected the M21 winning time to be about 70 - 80 minutes.

Transmitters #2, #3, and #4 were placed in pretty much a straight line on one side of the ravine with #1 and #5 placed on the other side of the ravine. This would require that most classes be able to find a route either through or around the ravine.

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