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Mapping

Show Profile  Paul I Posted: 17 May 2007, 8:27 PM  
Very Scary indeed!
I reckon less than half of the Czech fieldworkers in the above samples have produced a map which is up to scratch. With out seeing the terrain you can't say who is completely correct, but personally I like 'Martin's'style (the last one). He seems to have a good balance between too much small detail, and not enough, as some have done. His drawing is almost stylised to make the map visually asthetic and easy to read on the move. This is one point I brought up on our mapping workshop which no one seemed to notice, however we had very little time to discuss half the issues.
Without going into detail, those of us at the workshop didn't seem to be too far apart in our interpretations. Some thought that I put too much detail on White Lightening in some places, others thought I didn't show enough in others. Often features were agreed worthy of mapping but there were two different camps of how to show it.
The Czech exercise prooves that everyone eye sees the terrain differently, it can be as simple as looking at a contour height on a slightly different level.
The most important things are that our choice of what to map and what to leave off is consistant and correct, and that it is in the right place, trying at all times to keep the map readable and clear.
As Orienteers I think rather than thinking that the map may not have been perfect in your eyes we should perhaps focus on adapting and interpreting to the variety of mappers styles, after all, how else would you cope if you ran on all of the Czech maps on the above link?

Show Profile  Neil K Posted: 17 May 2007, 8:39 PM  
Wow. I'm amazed at how different they all are. Really different. Even countour shapes are completly different, I expected vegetation but not everything. I'm also amazed how as an orienteer I look at different maps and think....that would be a cool place to race...or that looks easy. Interestingly I got both those impressions from the same area mapped differently. Maybe our easy maps would become more technically challenging if we over paid some mapper (I suggest Paul) with express insructions to over map?

Show Profile  mick finn Posted: 18 May 2007, 7:05 AM  
Wouldn't we then need to get overweight orienteers to over run the controls?

Show Profile  Paul I Posted: 18 May 2007, 8:33 AM  
Conversly, you could underpay some other mapper to undermap a technically challenging and interesting area. Only underweight orienteers would do well. Over running controls would become a thing of the past.

Show Profile  Paul I Posted: 18 May 2007, 9:03 AM  
It would be interesting (to me anyway)to hear what your thoughts are on the various Czech mappers versions. To me Boris's is just wrong, Jans' is a jumbled mess, Pavel's seems all twisted like Neils brain, Milos clearly can't see contour shapes and should probably keep his day job and Tom is a real minimalist.

Show Profile  Greg Posted: 18 May 2007, 9:48 AM  
We have had under mapped maps and they are shit eg last years Nationals - bad idea

Show Profile  Svend Posted: 18 May 2007, 9:22 PM  
I have studied the Czech maps and it dosn't surprise me that Ales
Hejna has the best result. After all he is the most experienced of all the Czech mappers.
But lets have a good look at Martin's map since Paul seems to like it.
Firstly, he has too many unnecessary formlines.For example at the Eastern part of the map there is a hill with a formline re-entrant
on the West side. Why show the re-entrant? Everyone knows that a hill on a slope will form some sort of re-entrant on the uphill side,
showing it with a formline as well ridiculous and only serves to make it harder to read the map.
About the middle of the map there are some hills and knolls. Both Ales and Martin has shown the land form exactly the same but you only have to look at Ales's map for one second to get the information you need but on Martins map it would take longer to read the same details. The formline between the contours serves no purpose
whatsoever.
Martin has also got too many vegetation boundaries on his map. He has obviously not read the mapping specification regarding vege-
tation boundaries within the forest.
Many NZ forest maps have vegetation boundaries marked even if they are not distinct, let alone very distinct and on maps which has been
enlarged 50% the black dots can be very confusing.



Show Profile  Paul I Posted: 19 May 2007, 1:20 PM  
Hi Svend, you are more than likely correct about Martin's vegetation boundaries, and I completely agree with you that many NZ maps overuse them far too much. I also note that Martin is the only mapper to show a ride near the south east which suggests that he has overmapped this.
I also find Ales's map very good in most aspects. Overall it is simple to read and uncluttered.
My preference for Martin's map comes mainly because of the impression of land shape that he has created by closing contours together more on the steeper slopes and his precise use of form lines for the same reason.
I felt that in a couple of areas Ales's formline contours were not serving much of a purpose as you have thought about Martin's map.
With the knoll area on the hilltop I note that several of the other mappers have put in depressions here so although Ales's map is easier to read it may not be correct here.
The reentrant that you have highlighted as totally pointless is more of an issue with me as it is one of the reasons I didn't pick Ales's map as my preference. I know this is one of your pet hates as I remember you talking about it on another occasion. Yes Martin's looks like an unneccessary extra, but if you look at the other mappers some of them have gone to the point of showing a depression in here, so there is clearly a deeper than would be expected reentrant between the hillside and the knoll. The thing is Ales hasn't even shown that small hill, or the knoll above it, or the big reentrant below it. At the bottom of the steep slope just below the rectangular vegetation boundary there is clearly a plateau, many of the mappers showed a huge depression here, but I find Ales's version a poor representation in this spot. I get a very clear picture along that whole easters slope with Martin's map that I dont get with Ales's. I agree mostly with your thoughts about the other unneccessary formline that Martin has shown in the gully on the western side of the hill, he appears to have got carried away with trying to show the steepness, but I really don't think it destroys the map either.
Martin has shown more rocks, we can't debate these as we have no idea of their sizes. Half of the mappers have marked the distinct trees, half have not, either could be correct.

Does anyone know what sort of reputation Martin Telecky holds as a mapper in that part of the world?


Show Profile  Bryan Posted: 24 May 2007, 12:08 PM  
Here's my two bobs worth of comments.

Most of the maps are perfectly fine for Orienteering on. Most have some good points but all have areas which you could criticise and/or are wrong in places. I'm usually the worst critic of my own maps.

For example, I find Ales's map a bit too generalised for my liking. I really don't like the double formline in Martin's map and the use of multiple formlines makes the map a bit cluttered for my liking.

The best map would be if you could all combine the correct and best features of all the maps and create an average montage - this would be like mapping by committee or consensus. You can do this if you have time for a major event. We did this for WMOC2000 as we had several mappers with similar styles and the controllers and planners had plenty of time to ask me to fix up problems for areas which were undermapped/overmapped.

Show Profile  Greg Posted: 24 May 2007, 12:42 PM  
Surely you cant tell without actually going there.

Show Profile  Bryan Posted: 24 May 2007, 1:05 PM  
You can tell some features are wrongly mapped by comparing the maps against the others.

If most of the mappers had a feature in a certain spot and one mapper had it in a different spot then you would probably say that it has been wrongly mapped by that mapper.

Also, a lot of what we have been talking about is how a map is drawn, how a map is generalised and whether it is easy to read - a cartographer can tell just by looking at a map - obvious problems
are breaks in contours, stacked formlines, overgeneralisation of
a feature, invalid symbol sizes, too cluttered, overmapping.

Show Profile  Bryan Posted: 24 May 2007, 1:23 PM  
Just another comment. I think that a lot of the differences in the maps could be due to a poor base map. There's nothing better than having a good accurate base map to start with and a clear aerial photograph - unfortunately this is not often the case.

Show Profile  Paul I Posted: 24 May 2007, 2:00 PM  
Clearly they had quite a poor base map, I would say that here in NZ when we also get a poor base map we would get a similar wide variety of resulting maps. I think all efforts must go toward getting the best possible base maps to work with on all high profile mapping projects. One thing that was obvious on our recent Mapwalk on W/Lightning was that going over the completed map later with a blown up (larger scale) map, with the photogrammetry superimposed underneath made it very good and easy to see and make small changes here and there. Our fieldwork was done at 1:7500 by request as was the base photogrammetry, even though it is easier at 1:5000.

Show Profile  Michael Posted: 25 May 2007, 10:11 PM  
Interested in talking mapping on Sat night of QB vicinity Wellington? Focus on cartography rather than the field emphasis of Paul's mapwalk. Contact me at mapsport.co.nz

Show Profile  Michael Posted: 5 June 2007, 7:29 PM  
Anyone got any experience with "load symbols from..." I've avoided it because of fear of getting undefined symbols due to numbering changes, and I've done some laborious editing of old symbol tables to bring them into line with the current ISOM. And to do away with spurious duplicates caused by importing and pasting. Is there an easy way to tidy up symbol tables?


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