[Talk-us] GNIS Import Done

Eric Wolf ebwolf at gmail.com
Fri Mar 13 17:05:43 GMT 2009


Good sleuthing, David!

There are some mountain tops that are accurate. If you climb a
mountain and find a USGS monument, then I'll bet the GNIS data is
accurate. If there isn't one, it could easily be off by as much as 30m
(lowest expected accuracy of NED).

I'm sure, someplace at The Survey, there is an inventory of monuments.
It might be worth tracking that down and creating an accuracy
attribute during the import.

-Eric

-=--=---=----=----=---=--=-=--=---=----=---=--=-=-
Eric B. Wolf                          720-209-6818
USGS Geographer
Center of Excellence in GIScience
PhD Student
CU-Boulder - Geography




On Fri, Mar 13, 2009 at 9:55 AM, David Lynch <djlynch at gmail.com> wrote:
> If you go to the Board of Geographic Names site
> (http://geonames.usgs.gov/), it indicates that all elevations are from
> the National Elevation Dataset. (Which is probably what Garmin uses as
> well.) NED doesn't really have the spatial resolution to resolve
> features as small as the exact tops of mountains.
>
> On Fri, Mar 13, 2009 at 01:41, Apollinaris Schoell <aschoell at gmail.com> wrote:
>> How accurate is this data and how does it fit match with USGS maps? Just
>> checked one Peak I had entered some time ago.
>> USGS map 9735ft =2967m, GNIS import 2965m & position shift ~20m  (Garmin
>> TopoUS 2008 2964m)
>> position of USGS map and Yahoo matches exactly with my gpx tracks.
>>
>> Interesting to see USGS must have different data. And like in many other
>> cases Garmin has the wrong data ....
>>
>>
>> On Thu, Mar 12, 2009 at 6:29 AM, Ian Dees <ian.dees at gmail.com> wrote:
>>>
>>> Hi everyone,
>>>
>>> I completed the GNIS node import yesterday. Please see the wiki page [1]
>>> for more details.
>>>
>>> As several of you have messaged me and posted on this list, there are some
>>> problems with this data. Let me try to explain my thought process:
>>>
>>> 1. Since the resolution of the information is fairly low (i.e. a clinic,
>>> hospital, doctor's office, retirement home, etc. are all tagged "hospital"
>>> in their data set), I have absolutely zero problem with retagging data if
>>> you come across a feature that is incorrectly tagged. Not like you need my
>>> approval, but that higher resolution of info might convince the GNIS board
>>> to add some more tags to their data set.
>>>
>>> 2. I'm planning on taking the planet dump and grepping out all of the GNIS
>>> data. This will be used to generate diffs that we can send back to the GNIS
>>> board, who has the option of putting it back into their data set.
>>>
>>> 3. If there are already OSM features in your area for a certain node that
>>> I imported, feel free to delete my node, but please merge at least the
>>> gnis:feature_id tag from the GNIS data so that we can keep track of future
>>> name changes.
>>>
>>> -Ian
>>>
>>> [1] http://wiki.openstreetmap.org/wiki/USGS_GNIS
>>>
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>>
>>
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>
>
>
> --
> David J. Lynch
> djlynch at gmail.com
>
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