SLOW Micro-O at Esher

[distracted]

Mirc-O maps are at 1:5000 to let you see the detail more clearly... there is no extra detail added in.

You obviously haven't seen the 1:10 and 1:5 maps of Esher then? The fact that the micr-O map had 2.5m contours tells you something... There was a hell of a lot more detail on the Micr-O map - why else would it have been made especially for the event

[mharky]

Because there are a lot of mappers in the UK who actually aren't very good, and clubs use them because they are cheaper than the good mappers?

In all other mirc-o's the map has been the 1:10 at 1:5... same map.

In the same way the forest sprints are the same map at 1:5, it's only urban and parks where detail gets added on, for good reason

[FatBoy]

Look Mharky - reread my post. I am agreeing with everything you say.

I said Leith Hill is harder than Esher, regardless of what scale you map Esher at, or indeed whether Leith Hill was to be mapped at 1:10 or 1:15. The only reason Leith Hill has a perception of now being TD5 (or more technically correct, capable of supporting TD5 legs) is that it's now mapped well enough to do so. The area was of course TD5 capable all along.

Fact is I don't think anybody involved with mapping/planning Esher thought it's TD5. Graeme suggested that by mapping it well it becomes TD5 (as per Leith Hill). I put that straight to say no matter what scale you make a map at the distance from a cast iron line feature will not change.

I also said that I do think MicrO should be 1:5000 (in fact I think that's a standard - you know I like those).

So how much mapping have you done then Mharky seeing as you seem to be such an expert?

[graeme]

Middle distances have been at 1:10 for a long time, its an IOF norm.

In fact they've been at 1:10 ever since they were short distances

At some point though, the IOF definition of a 1:10 map went from being a blown-up

version of a legible1:15 with no extra detail added, to actually being surveyed for
1:10.

Meanwhile BOF's definition of 1:15 has come to include photoreduction of 1:10 maps. Including those originally surveyed at 1:10 because "there are so many details that 1:15 would be illegible".

When did all that happen?

Graeme

Because there are a lot of mappers in the UK who actually aren't very good, and clubs use them because they are cheaper than the good mappers?

e.g. me.

Also, there are good mappers who don't put in the time to make good maps.

Graeme suggested that by mapping it well it becomes TD5. I put that straight...

What I actually said was that on a good map the fastest way to orienteer is using TD5 techniques (mapreading), while on a poor map its faster to use TD4 (attackpoint, get to right area quickly, hunt around). As you say,this is not the formal definition of a "TD5"
area.

[mharky]

I show you mine if you show me yours...

I know someone who knows a lot about Middlebrough football club, which is strange because he has never played for them...

[gross2007]

So how much mapping have you done then Mharky seeing as you seem to be such an expert?

I don't think it matter much how much mapping you've done to understand what is a good map / bad map / poor map. A good orienteer will easily be able to assess the quality of a map & will actually adjust his/her techniques to the map's standard.

I agree with Mharky in that a lot of UK maps are not actually very good... maybe one reason is that many areas aren't technical really and therefore most orienteers don't notice.

What is most annoying is going out on an area in Scotland that's been advertised heavily as a great new technical forest..... only to get out there & find half the spurs / re-entrants on the ground run in a totally different direction on the map. Seems like quite a few mappers can't map contours well....................

[FatBoy]

I think a good orienteer can tell a good map from a bad one. It's only when you start mapping though do you realise how little of what's on the ground do you need to put on a map to be able to navigate to the significant features. I'm not saying I'm a good mapper however, but I've done a few updates.

[distracted]

In all other mirc-o's the map has been the 1:10 at 1:5... same map.

How can you fail not to have more detail on a map when the contour interval is 2.5m rather than 5m in an area of relatively complex contour detail??? It doesn't matter what the scale of the map is in that case.

[David May]

As the one who commissioned the Esher map, it's probably worth explaining why we did what we did. The first thing was to look for an area with a high density of features, and similar features too, and this means that in most cases you look for contour features.

Esher has two main patches meeting this criterion, Oxshott Common in the SE and the nameless ridge we did use. Oxshott had too much undergrowth to be attractive, so we went for "Esher Common Central" instead. Those who have seen the 10000 mapping of this ridge will realise why it needed a complete resurvey for 1:5000 Micr-O purposes, especially as 2.5 m contours were needed. I did briefly think that I could update it myself but quickly realised that it needed a practised professional instead.

Although I agree with much of what Mharky has posted about Micr-O, I don't know where he gets his info from that Micr-O maps have no extra detail, and also that at all other Micr-Os the map has been the same as the 1:10000 but enlarged.
Firstly, there have been precious few proper Micr-O events anyway, so "all other Micr-Os" won't use more then the fingers of one hand to count! This year's Nordics was the most prominent and they drew a special map for this. Indeed, their guidelines say

6. GUIDELINES FOR THE MICR-O NOC 2005
- The map scale is 1:5000 with 2.5 m contour interval. The map will be surveyed and drawn according to ISOM and the special rules for Micr-O at NOC 2005.

The Micr-O standard contour interval is 2.5 m precisely so that more detail can be mapped. Unless the terrain is steep, it's much harder to get a big enough feature density with a 5 m interval to make Micr-O interesting.

So, yes, Micr-O is interesting to plan and compete in - the downside is that you need a resurvey before you have a good enough map. Of course, many Sprint maps already meet the Micr-O scale criteria - perhaps this is the natural home for Micr-O controls in the future ...

David

[David May]

Those who contributed to the online survey about the Micr-O event at Esher (all 54 of you), and of course anyone else who might be interested, might like to look at the analysis of the main responses at http://www.wcup2005.org.uk/page.aspx?id=15810

David