What is it with the North East?

[Ed]

Surely, the age of the plot is not especially important? What are important are things like was the ground clear at the time of the aerial photos, the quality of the photos, the quality of the plot etc. So, for instance, there was no ground cover for the Kilnsey photos (obviously!), and the plot was by Stirling Surveys. It'll probably be good for many years to come, as long as the quarry doesn't continue to grow too fast!

if you're talking about mapping contours from the plot, probably not important, but if you're talking about mapping vegetation/paths from the plot, then yes it is - and since those are the features that seem to have been contentious at Kyloe then only an up-to-date plot (or even just an orthophoto) would have done.

As for old plots - mapping (and pg plot) standards/styles have changed since the 1970s. I personally find the contours in Darnaway (still from the 1976 WOC map) hard to interpret - I suspect that if they were mapped again from scratch then they would come out a bit different.

[graeme]

We had an excellent example of this the previous week at TINTO's Alterstone event - another slow, rough, green borders plantation, rather smaller and steeper then Kyloe. I'd run there a couple of years before with an OS map to look at viability - just random directions through the terrain. I thought it was absolutely horrible. With a brand new map, from new photos, despite most of the vegetation mapped as indistinct it was possible to plan and micro-navigate around the bits I'd got stuck in before. Pretty much everyone came away happy.

Graeme

[neil m37]

Graeme, from your comments I think you are suggesting that the SOA is advocating new PG plots for all major events in future. What other strategies are SOA considering to ensure that maps are adequate for major events?

By the way the list of maps/plot dates I gave was intended to point out that the NE was only following the practice of most other events - I was not suggesting that there was anything wrong with any of the maps. However I am sure the mappers job would be easier and the resulting map even better if a new plot was available. Brown Clee and Hambleden in particular would have seen considerable changes in the path network and vegetation from the plot used (but not Kilnsey - it doesn't have any paths or vegetation)

[graeme]

I'm not speaking for SOA, and even then SOA can't force clubs to do things. We do offer centralised mapping grants for clubs who can't afford it, and a stock of "SOA" areas for use by any club who wants to. I do think that the cost of good basemaps (not just for plots) can be more than recouped in better final product and less effort for the mapper.

As people are saying, I don't generally think you need new photogrammetry. We're not re-PG'ing Glen Dye/Bogendriep for the Scottish. But I do think maps based on PG plots are sharper than those that aren't (I would argue your list bears that out) - thats why the professional mappers insist on it. And occasionally a new basemap is worth doing I don't have a problem with "amateur" or "part time" mappers, but I don't think they should have to struggle with poorer basemaps than "professionals" which they often seem to.

If SOA has a policy, it is the exact opposite of one of the guest who implied "we dont get enough people coming, so we can't afford to improve our maps". i.e. "we need to improve our maps to ensure that people will come".

Some people will argue a total remap of something good enough for a JK can't make much difference to an area. Other people went to Leith Hill.

Graeme[/i]

[neil m37]

There has been another National event this year where the map wasn't adequate.

That's absolutely true. And the association in question has recognised the problem and is doing everything it can to make sure it doesn't happen again.

Which would appear to be nothing much at all then, other than suggesting that clubs might like to think about getting a new base map.

You advocate PG plots because you can accurately map the vegetation but don't think it needs to be a new PG plot which means the vegetation won't be accurate? Or have I missed something?

[neil m37]

sorry, I've had a frustrating day.

How about
Maps are generally better if they are based on a pg plot (I think we agree on this). It would be preferable to have as recent a plot as possible, but this is not essential unless it is an area where there are likely to have been a lot of changes (perhaps that is stating the obvious).

A map is not necessarily good or bad depending on whether or not it was ever based on a pg plot. Every map should be judged on its own merits.

And the Kyloe map was fine - I was speaking to somebody English yesterday who agreed with me.

[Ed]

if it's only vegetation/path updating/mapping that's needed (i.e. not contours), you don't need a pg plot - an orthophoto (aerial photo that's corrected so that distortions from the camera lens and terrain relief are removed, like the ones on multimap) would suffice, and would probably be a lot cheaper to get hold of (doesn't need Sterling Surveys to sit there for hours plotting the contours and veg boundaries from a pair of stereo photos - you can pick out paths and veg boundaries (and even distinct trees, buildings, etc.) yourself easily enough from a decent resolution orthophoto)

[Freefall]

Good to pick up on the positive comments about my planning at Kyloe. The map was certainly up to standard and I am not aware of any control sites where competitors were disadvantaged by the vegetation mapping. Controls were generally hung high and prominently and if you were in the right area you would find them. Pleased that all the winning times on the Long and A Courses were about right - the Short and B competitors did struggle, and yes the brashings were tough. It wasn't a huge amount of fun carrying a bundle of control stakes around and I should have thought running around the area was relatively easy compared to the planners efforts. The last controls were collected in the dark and I still found them easily enough.

I hope you do come back to the next event - personal preference is in the early part of the year when the vegetation is down. A carpark adjacent to the area would also help and we will start negotiations for those who are troubled by a 2 km walk for the kiddies.