For how many maps are out there, I would say it's fairly rare that the USGS just has a blatant fail So when I find them I tend to take note and have started to collect them
I mean a true failure, not just the trail being off, or a road being outdated. Perdition being misnumbered, about 1/2 sq mile out near Dufur being 'mirrored' from reality etc..
Tonights find: (virtual cookie and brownie points to whoever spots it first!)
USGS Fail!
Re: USGS Fail!
Correct good sir!
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- Posts: 59
- Joined: March 1st, 2014, 5:28 pm
Re: USGS Fail!
... the true art is the initial find. Nice. The type of error you posted here is due to duplicate information, the bane of database systems. In the a better world, the map maker would specify only the location of the number, not its value. I guess. Never studied map making myself.
Re: USGS Fail!
I'm curious about other errors people have found
Re: USGS Fail!
I had some creeks crossing up near Sequim in the late 90s. I was surveying Jimmy Come Lately Creek and one of the tributaries crossed the creek on the map and went elsewhere. I don't believe it went uphill anywhere, but I'd love to see that map again without spending that $8 USGS wants for the old maps.Lurch wrote:I'm curious about other errors people have found
- Michael
Re: USGS Fail!
I believe you can download most, no?aiwetir wrote:I'd love to see that map again without spending that $8 USGS wants for the old maps.
Karl
Back on the trail, again...
Back on the trail, again...
Re: USGS Fail!
Yes, you can download USGS maps at different scales dating back years at that site. Similar USFS maps (good for forest roads) can be found at USFS maps. The USFS maps tend to mirror the USGS maps, so you might find the same errors on both. Still, the error rate is staggeringly small relative to the number of maps involved.kepPNW wrote:I believe you can download most, no?aiwetir wrote:I'd love to see that map again without spending that $8 USGS wants for the old maps.
In this instance, the contour lines not aligning properly seems to be the result of a map join and not an error within a given map. CalTopo shows this joining issue quite often.
- retired jerry
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- Joined: May 28th, 2008, 10:03 pm
Re: USGS Fail!
yeah, one quad is at one resolution, adjacent quad at different resolution
back from the bad old days when you had a paper map for each quad
back from the bad old days when you had a paper map for each quad
Re: USGS Fail!
Part of this is inherent in mapping in general. Because the 'standard' USGS quads are 7.5" maps, they're covering 7.5 minutes of latitude and longitude, and are slightly trapezoidal, and will cause some alignment issues when you try and stitch them all together.. The whole flat faces on a spherical surface bit.. It's also good to be aware that different maps have different contour intervals, so your topo lines may double, or half, at the borders.VanMarmot wrote:Yes, you can download USGS maps at different scales dating back years at that site. Similar USFS maps (good for forest roads) can be found at USFS maps. The USFS maps tend to mirror the USGS maps, so you might find the same errors on both. Still, the error rate is staggeringly small relative to the number of maps involved.kepPNW wrote:I believe you can download most, no?aiwetir wrote:I'd love to see that map again without spending that $8 USGS wants for the old maps.
In this instance, the contour lines not aligning properly seems to be the result of a map join and not an error within a given map. CalTopo shows this joining issue quite often.
Nesmith is a prime example of this: It's easy to tell in the steep face, but can look more like an alignment problem in the flatter areas unless you pay close attention to the contour interval and realize it shifts from 40' to 80'