View Dave Goes Orienteering 2012-13 in a larger map
I was supposed to help set up before the o-meet. I arrived 10 minutes later than I was supposed to be there, 50 minutes before the meet was due to begin. There were already 15-20 people there waiting to orienteer in addition to the folks setting up the meet. There wasn't much for me to do at that point so after standing around for a half hour or more I paid my event fee and did a course.
Meadowood has always been a challenge for me, and others. Part of the problem is that the map isn't as good as it could or should be. The club has yet to get the sort of data it needs to update the map. In particular there are trails and contours missing from the map. On most (if not all) of the advanced courses I'm sure that made a difference. I know that I felt it on the blue course.
The first time I had problems that I would attribute to the map was when I was searching for control 4/126. There was at least one re-entrant which I mistook for the entrant that the control was just above. I spent a few minutes searching it before deciding that it must be an unmapped feature. When I did find the control it was because I was following a trail which was mapped.
Control 7/101 seems to have been placed on the wrong root stock. There were two of them marked on the map. The map indicates that it should have been on the northern one but instead it was on the southern one. This gave me a little bit of trouble. I circled around for a little while before I found it with a little help from a couple other people who found it first.
Control 8/109 was not misplaced but I did a poor job when it came to finding it. I got in the general area and then tried cutting cross country instead of following a trail. When I did eventually find it was because I relented and took a trail.
Control 11/115 probably shouldn't have given me as much trouble as it did. I wasn't low enough into the re-entrant when I started looking for it. First I walked southeast along the re-entrant, then I tried heading northwest, and finally southeast again. Each time I got a little closer to the center of the re-entrant and on the third try, just as I was starting to get desperate, I found the control.
Control 13/129 wasn't easy to find. I knew that it was north of the trail I used to get in the general area of the control. What I couldn't figure out was where I should leave the trail and head north. I ended up much further west than I needed to go. When I started to head back east I wasn't sure where I was in relation to the control. I wandered a bit, got lucky and little bit of help from another orienteer.
The map is one of the key tools that orienteers use. When a map is as inaccurate as the Meadowood map is it shakes my confidence in it and my own abilities. There is no backup system for the map. What I end up doing is trying to figure out where the map is accurate. This usually adds to the time it takes me to find controls. Such was the case today.
On the plus side the weather was gorgeous. It was a little warm but not too warm. On the down side the bugs were out in full force and I came home with lots of little bites.
I stuck around after the meet to help clean up. After that I went to dinner with Dan and Jon. We ate at Busboys and Poets in Shirlington. I had hummus; black beans, wild rice, and grilled chicken; and banana bread, white chocolate pudding.
Course: Blue [Controls: 18; 8.8 km; 235 m]
Time: 3:40:46 - WinSplits - RouteGadget - AttackPoint
Actual Distance: 14.01 km
No denying it, the map was made from a base of relatively low resolution LiDAR data so the result doesn't capture the subtle terrain detail as well as would be ideal. Fortunately, we plan on fixing that in the coming leaf off season with a LiDAR survey covering pretty all of our existing maps starting from Mason Neck and more or less sweeping along the Occoquan towards Manassas.
ReplyDeleteI can't say I noticed any unmapped trails though, at least not distinct, well-trodden trails. Still I heard this from other people. I should ask people where they encountered them while memories are still fresh. Although it looks as though there will probably be a fresh crop of new mountain biking trails by the next time we use the park so we'll presumably catch anything else when the time comes to survey those.
Regarding your problem controls, 7 was clearly on the wrong rootstock (though I thought it was on an unmapped one, not on the mapped one it seems to have been on - not sure how Sid managed that mistake if they're mapped accurately as having trunks pointed in quite different directions) and 13 also looks to have been slightly off. 8 and 11 look like clear examples of paying the price for not having an attack point. Your miss on 4 was a bit of a shame given you had a bombproof attack point - was your bearing off or did you mean to aim off west of the control feature and then get confused by the apparently unmapped reentrant? Which is rough - ordinarily assuming you're right and the map isn't is a bad move but when you aren't quite sure of the map quality, yeah, it can be hard to know what to trust.
The unmapped trails that I encountered (or at least thought I did, I'm looking at the map and starting to wonder if I was just misreading it) were in the southern portion of the map. In particular when I was looking for 13.
ReplyDeleteSometimes I get overconfident, sometimes I get sloppy, and sometimes I just get fatigued. Sometimes I get lucky and can get away with a haphazard approach. I blame a mix of overconfidence and sloppiness in the cases of 8 and 11. I should have known better.
In the case of 4 it looks like I picked the wrong trail off which to navigate. I was on the trail I intended to be on but the extra re-entrant threw me off. If I had used the other trail and just kept going south once the trail turned east I would or should have been found it sooner.