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Mapping

Show Profile  olde codger Posted: 28 June 2006, 8:23 PM  
The ankle deep depression 133was on the orginal '92 map and I take full responsibility for not taking it off.I seem to recall laughing at it when field working and putting a line through it but some how it never got transfered to the draft map that went to Marquita. Shit happens.An experieced controller should have deleted it and called it an re-entrant.When I'm mapping an area of complex dunes I always map the positive features first. If there is a debatable depression (even deeper than 1m)in between 2 knolls close together( 5m or less) , it will not be mapped. If there is some distance, say 10 m and can be comfortably fitted in with out running into contour lines when reduced I will map it, even if it is 0.75m . I don't map any thing less then that.It's really in the context of the surrounding terrian. I know of mappers who imagination gets carried away i.e Waiuku Thousand Clearings where ankle size knolls & depression, faint clearings,were mapped for the sake of mapping them to justify a job.
I'm not really in favour of moving point features to fit them in.One case was on one of Michael's maps we have been working on, were a pit was mapped in the middle between a hill and knoll which were 20 apart .Couldn't find anything were it was mapped but did find it next to the knoll. An orienteer would expect the control to placed in the centre of the cicle. In this case it would have been just in the circle.It would have been better left off and just the positive feature mapped.
I'm all in favour of a meeting of practicing mappers so we can all be consistant in style.

Show Profile  Michael Posted: 4 August 2006, 2:04 PM  
Quite happy to accept that some solutions to tight situations may not be optimum - we can be visiting a feature a minute. I agree that leaving the negative feature off is often the best policy.

The real culprit continues to be wrong symbol sizes. The Winter Classic wasn't an A level event and is deliberately "idiosyncratic". But presumably the symbol sizes were the same when the map (Halcione) was used for the NZ Champs, and they appear to be too small. And that nifty "dot inside a U" symbol - how many of them were ever fully qualifying knolls (1m high) next to a fully qualifying depression (1m deep)? So that standing in the depression the knoll would be over your head...

Show Profile  Greg Posted: 4 August 2006, 2:30 PM  
If it is a new symbol then wouldn't the minimum dimension be 1 m from bottom of depression to top of knoll. As I understood it, its not 2 separate features but 1 feature comprising of 2 things

Show Profile  Michael Posted: 5 August 2006, 10:51 AM  
You're right Greg that it was a new symbol defined (tho I can't remember what as) in the competitor info at the time. My mistake for introducing a red herring to the main culprit, which is...

Show Profile  Neil K Posted: 5 August 2006, 2:00 PM  
Hi Micheal, if your going to use "..." in the middle of the sentence, please tell us which new thread your using to finish the sentence.

Show Profile  onemanfanclub Posted: 5 August 2006, 3:28 PM  
Neil, if you're going to type in a sarcastic tone, please do it in a new thread

Show Profile  Greg Posted: 5 August 2006, 3:50 PM  
I believe Michael likes to see all abuse in a different thread

Show Profile  Michael Posted: 23 August 2006, 12:08 PM  
The symbols on Pukepuke (WOA OY4) were too small. While only of regional significance it's disappointing to have to go back to techniques of 20 years ago - compass/pace into the circle then look for any feature that matches the control description.

Across the Tasman the issue has come up too. Orienteering Australia Tech Newsletter 2/06 discusses this and the Mapping Chair says that non-ISOM or ISSOM maps should not be allowed for major events. In other words symbols for 10,000 should be 50% larger.

This message was edited by Michael on 23 August 2006, 2:28 PM

Show Profile  robbie Posted: 27 August 2006, 8:35 PM  
Very interesting
Its simple We operate under one set of rules
So STOP fiddling with he symbols

Show Profile  Jamie Posted: 28 August 2006, 7:34 AM  
???

Show Profile  AlanHorn Posted: 28 August 2006, 9:10 AM  
Ive noticed some of our OCAD maps are 1:15000 but others are 1:10000.
But is there an easy way to tell in OCAD whether the symbol set associated with the map has been changed or not without printing a map and physically measuring them?

Is there a good source for a "default" symbol set for 1:15000 and 1:10000 map scales somewhere?

(not an OCAD expert)




Show Profile  Martin Posted: 28 August 2006, 10:17 AM  
The best way is to go into an individual symbol and check its size.
For circular point symbols (dot knoll, water trough etc):
right click on symbol > edit then click on the image and check the diameter. at 1:10000 at dot knoll has diameter 0.75mm, at 1:15000 it will be 0.50mm

For linear features (contours, streams, fences, tracks):
right click on symbol > then check the line width, at 1:10000 a contour should be 0.21mm, at 1:15000 it will be 0.14mm

Check out the ISOM 2000 for the exact details. All the technical mappign stuff is on http://lazarus.elte.hu/mc/

One last thing... to CHANGE the scale of a map do Extras>Change Scale and have enlarge/reduce symbols box selected 0 this is the most important thing!

DON'T do Options>Scale as this is only for checking the scale of the map. DON'T just change the size of a symbol to make it fit in with everything around.

ISOM symbol set (1:10000,1:15000) http://www.ocad.com/en/orienteering.htm
ISSOM sprint symbol set
http://lazarus.elte.hu/mc/specs/issom-2005-english-ocad8.ocd

If you think you have a dodgy symbol set then download a new one and go Symbol>'Load symbols from...'

As always make a backup before you start working with the file.

This message was edited by Martin on 28 August 2006, 11:20 AM

Show Profile  Michael Posted: 4 October 2006, 11:45 AM  
The symbols on "White Lightning" (Auck Champs) appear to be undersize. It's bad enough that some existing maps remain unchanged 6 years after the current specification came in, but this was a brand new area.

Show Profile  Marquita G Posted: 4 October 2006, 12:19 PM  
Get some new glasses Michael. The symbols are exactly the correct size for 1:10,000; after the flak over Otakanini I was particuarly firm about this despite pleas to reduce the sizes from the mappers. The only exception to this is where one of the mappers did a few corrections and unbeknown to me made some really really small knolls. I intend to change these back to correct size before the area is used again.

Show Profile  Martin Posted: 4 October 2006, 1:14 PM  
will this thread ever die?!?! I thought White Lightning was a bloody awesome map


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