Discussion: Lines
in: PG; PG > 2011-05-01
May 1, 2011 9:43 PM
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walk:
There do seem to be a few stray lines in that area and some missing. Not J-J's work I assume.
May 1, 2011 11:47 PM
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jima:
Green X did that loop in reverse - your 1-2-3-4 was our 4-3-2-1, so we got the benefit of running down over 2 index contours. Was wondering where that momentary burst of energy came from...
May 2, 2011 1:57 AM
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Well, what can I say? Not exactly my work, but I was involved. I drafted the stuff SE of Rte. 293 plus Bull Pond, and Pat drafted the rest. Roughly speaking, all of the fieldwork came from Mikell except for the SEmost piece of terrain (originally known as Turkey Mountain). Back around 2003 I took data files that Pat had exported from his CAD system to 0CAD, and merged all of the maps together into one big 0CAD file.
The issue that rears it head here is that Pat drafted different maps at different times, and funny things happened along the seams (and there may have been weird stuff in the fieldwork here and there as well). I don't remember whether the files from Pat already had index contours in them, or if I switched every fifth line to be thicker, but either way, it's a lot of work to chase all of those lines around the map and look for conflicts.
That said, I do have some information. If you look on the slope north of Jim's Pond, you'll see that a contour vanishes somewhere, and it stays vanished for a long time (the matching discontinuity is south of the "300" in the graphic scale). Other than that things seem okay visually, but in the data it's more confused. If you look at the cliff on the hill at the E end of Jim's Pond where one index contour splits into two, the index contour coming in from the east is actually a continuous object with the upper index contour, rather than the lower one. Clearly wrong. I would have fixed this if I had noticed it.
Still, not as bad as the map in Uslar, Germany, where the number of regular contours between index contours (which should always be four) changes from two to seven as you cross a road.
The issue that rears it head here is that Pat drafted different maps at different times, and funny things happened along the seams (and there may have been weird stuff in the fieldwork here and there as well). I don't remember whether the files from Pat already had index contours in them, or if I switched every fifth line to be thicker, but either way, it's a lot of work to chase all of those lines around the map and look for conflicts.
That said, I do have some information. If you look on the slope north of Jim's Pond, you'll see that a contour vanishes somewhere, and it stays vanished for a long time (the matching discontinuity is south of the "300" in the graphic scale). Other than that things seem okay visually, but in the data it's more confused. If you look at the cliff on the hill at the E end of Jim's Pond where one index contour splits into two, the index contour coming in from the east is actually a continuous object with the upper index contour, rather than the lower one. Clearly wrong. I would have fixed this if I had noticed it.
Still, not as bad as the map in Uslar, Germany, where the number of regular contours between index contours (which should always be four) changes from two to seven as you cross a road.
This discussion thread is closed.