Re: [Talk-us] NHD import
On Sun, Apr 8, 2012 at 10:39 PM, Martijn van Exel mve...@gmail.com wrote: Hi, Remapping in CA, I come across some weird stuff. Here's some NHD 'data': http://www.openstreetmap.org/?**lat=35.17764lon=-119.12641**zoom=16http://www.openstreetmap.org/?lat=35.17764lon=-119.12641zoom=16 Either the aerial imagery is way off here, or this is just bad data. If it is, I presume that there has been a review of this data before import, this is the exception, and the vast majority of imported NHD objects actually do represent reality. I hope. -- Martijn van Exel Are you talking about the water - lakes and ponds? From reading nmixter's diary, he/she has posted comments about mapping farms. One comment suggested taking the import to the talk-us mailing list. BTW - I did just drive through some farm land in Western Washington. Farmers had dug temporary canals to help drain (or so I assumed) the water from the field so they could plant. I probably wouldn't map it unless they were permanent. -- Clifford ___ Talk-us mailing list Talk-us@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk-us
Re: [Talk-us] NHD import
On 4/9/2012 12:00 AM, Clifford Snow wrote: On Sun, Apr 8, 2012 at 10:39 PM, Martijn van Exel mve...@gmail.com mailto:mve...@gmail.com wrote: Hi, Remapping in CA, I come across some weird stuff. Here's some NHD 'data': http://www.openstreetmap.org/?__lat=35.17764lon=-119.12641__zoom=16 http://www.openstreetmap.org/?lat=35.17764lon=-119.12641zoom=16 Either the aerial imagery is way off here, or this is just bad data. If it is, I presume that there has been a review of this data before import, this is the exception, and the vast majority of imported NHD objects actually do represent reality. I hope. -- Martijn van Exel Are you talking about the water - lakes and ponds? From reading nmixter's diary, he/she has posted comments about mapping farms. One comment suggested taking the import to the talk-us mailing list. BTW - I did just drive through some farm land in Western Washington. Farmers had dug temporary canals to help drain (or so I assumed) the water from the field so they could plant. I probably wouldn't map it unless they were permanent. Yes, I see a lot of water features that are just not corroborated by the aerial imagery, which could mean one of at least three things: 1) The aerial imagery is out of date 2) The NHD data is out of date 3) The NHD data represents something I don't understand (the future, a temporary situation (which should not be in OSM), something underground?) -- Martijn van Exel ___ Talk-us mailing list Talk-us@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk-us
Re: [Talk-us] NHD import
Yes, I see a lot of water features that are just not corroborated by the aerial imagery, which could mean one of at least three things: 1) The aerial imagery is out of date 2) The NHD data is out of date 3) The NHD data represents something I don't understand (the future, a temporary situation (which should not be in OSM), something underground?) Some of the water features in NHD are also seasonal, although that is usually tagged in the data. Also irrigation canals are often just ditches and can be hard to identify from aerial imagery especially the smaller ones as they aren't always in use. The tags on a lot of those features have some gnis:type tags that say ditch-canal or something like that but the OSM tag is just canal which doesn't really do a great job describing the situation exactly. I agree, though, the data you pointed out looks pretty odd, especially the square shapes. I'm surprised that NHD has data that includes irrigation ditches as small as some of the ones noted above. Anybody know how they gathered all of that data? Greg ___ Talk-us mailing list Talk-us@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk-us
Re: [Talk-us] NHD import
On Mon, Apr 9, 2012 at 1:25 AM, Gregory Arenius greg...@arenius.com wrote: Yes, I see a lot of water features that are just not corroborated by the aerial imagery, which could mean one of at least three things: 1) The aerial imagery is out of date 2) The NHD data is out of date 3) The NHD data represents something I don't understand (the future, a temporary situation (which should not be in OSM), something underground?) Some of the water features in NHD are also seasonal, although that is usually tagged in the data. Also irrigation canals are often just ditches and can be hard to identify from aerial imagery especially the smaller ones as they aren't always in use. The tags on a lot of those features have some gnis:type tags that say ditch-canal or something like that but the OSM tag is just canal which doesn't really do a great job describing the situation exactly. I agree, though, the data you pointed out looks pretty odd, especially the square shapes. I'm surprised that NHD has data that includes irrigation ditches as small as some of the ones noted above. Anybody know how they gathered all of that data? Greg I saw some odd water features along the coast in California as well when I was remapping coastlines by importing some NHD data. I don't have a link handy but I think it came from a California specific data source and some of the ways didn't have any OSM renderable tags. Yay for imports? Toby ___ Talk-us mailing list Talk-us@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk-us
Re: [Talk-us] NHD import
On 4/9/2012 1:39 AM, Martijn van Exel wrote: Here's some NHD 'data': Perhaps rice fields, based on a Google Street View, but I can't see for sure. ___ Talk-us mailing list Talk-us@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk-us
Re: [Talk-us] NHD import
I had to teach a class on Friday and it involved NHD Data. NHD data is supposed to be an ever evolving dataset. The beginning's of it are 1:24k USGS Topographic Maps. As time goes on and Lidar http://en.wikipedia.org/wiki/LIDARbecomes more prevalent the dataset will improve. Tennessee is slated to get a high resolution dataset of NHD data collected form photogrametrically acquired data in the next few years. Because NHD data is based of 1:24k quad sheets (and in come cases USFWS Wetland Maps) it's dated - in Chattanooga it's probably 40 to 50 years old. Streams change. Ponds disappear. Things become channelized. If you compare it to the NAIP or Bing Aerial Imagery in some cases it's remarkably close and in some it so far off you wonder what happened. There is also a second glitch with the data - since NHD is based off the 1:24k topo maps it's not entirely accurate. The USGS changed their definitions of what consisted of a blue line stream from it's a drain to it's got water in it. It didn't affect Lakes/Rivers so much but the blue line streams are questionable unless they are viewed with Aerial Photography (and in my opinion need to be viewed in Stereo or site visit to see what is occurring with it). I say all of that - it's better than having nothing. At least here we can improve it. Randy Randal Hale, GISP North River Geographic Systems, Inc http://www.northrivergeographic.com 423.653.3611 rjh...@northrivergeographic.com twitter:rjhale http://about.me/rjhale On 4/9/2012 2:11 AM, Martijn van Exel wrote: On 4/9/2012 12:00 AM, Clifford Snow wrote: On Sun, Apr 8, 2012 at 10:39 PM, Martijn van Exel mve...@gmail.com mailto:mve...@gmail.com wrote: Hi, Remapping in CA, I come across some weird stuff. Here's some NHD 'data': http://www.openstreetmap.org/?__lat=35.17764lon=-119.12641__zoom=16 http://www.openstreetmap.org/?lat=35.17764lon=-119.12641zoom=16 Either the aerial imagery is way off here, or this is just bad data. If it is, I presume that there has been a review of this data before import, this is the exception, and the vast majority of imported NHD objects actually do represent reality. I hope. -- Martijn van Exel Are you talking about the water - lakes and ponds? From reading nmixter's diary, he/she has posted comments about mapping farms. One comment suggested taking the import to the talk-us mailing list. BTW - I did just drive through some farm land in Western Washington. Farmers had dug temporary canals to help drain (or so I assumed) the water from the field so they could plant. I probably wouldn't map it unless they were permanent. Yes, I see a lot of water features that are just not corroborated by the aerial imagery, which could mean one of at least three things: 1) The aerial imagery is out of date 2) The NHD data is out of date 3) The NHD data represents something I don't understand (the future, a temporary situation (which should not be in OSM), something underground?) ___ Talk-us mailing list Talk-us@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk-us
Re: [Talk-us] NHD import
Most recent USGS topos show that area as water features. NAIP 2012 shows water there; looks like wetlands restoration maybe? --Brett Brett Lord-Castillo Information Systems Designer/GIS Programmer St. Louis County Police Office of Emergency Management 14847 Ladue Bluffs Crossing Drive Chesterfield, MO 63017 Office: 314-628-5400 Fax: 314-628-5508 Direct: 314-628-5407 ___ Talk-us mailing list Talk-us@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk-us
Re: [Talk-us] NHD import
If it were coastal Oregon or SW Washington, there would be a good chance that those were Cranberry farms (bogs). Tanya On Mon, Apr 9, 2012 at 6:28 AM, Brett Lord-Casitllo marigol...@yahoo.comwrote: Most recent USGS topos show that area as water features. NAIP 2012 shows water there; looks like wetlands restoration maybe? --Brett Brett Lord-Castillo Information Systems Designer/GIS Programmer St. Louis County Police Office of Emergency Management 14847 Ladue Bluffs Crossing Drive Chesterfield, MO 63017 Office: 314-628-5400Fax: 314-628-5508 Direct: 314-628-5407 ___ Talk-us mailing list Talk-us@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk-us ___ Talk-us mailing list Talk-us@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk-us
Re: [Talk-us] Highway Shield Rendering
Is there a reason there are no shields or fallback ovals here on Nocatee Parkway? http://elrond.aperiodic.net/shields/?zoom=15lat=30.12344lon=-81.39063layers=B0 The way is tagged ref=CR 210 and the relation is network=US:FL:CR:St. Johns ref=210. ___ Talk-us mailing list Talk-us@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk-us
Re: [Talk-us] Highway Shield Rendering
* Nathan Edgars II nerou...@gmail.com [2012-04-09 17:40 -0400]: Is there a reason there are no shields or fallback ovals here on Nocatee Parkway? http://elrond.aperiodic.net/shields/?zoom=15lat=30.12344lon=-81.39063layers=B0 The way is tagged ref=CR 210 and the relation is network=US:FL:CR:St. Johns ref=210. The short answer is that it appears to be a rendering bug. The happy response is that I just finished a reworking of the shield image generation process[0] which appears to have fixed that bug as a side effect. County shield support is still pending[1], so it just gets the fallback shields for now. [0] The main benefit is that shield clusters are now generated on demand, rather than in a separate batch process. This should help keep the rendered map more up to date. [1] Including New Jersey county routes. I took them out because they didn't really fit into the code reworking I did. They'll return when I get the general-purpose county shield rendering working. -- ...computer contrarian of the first order... / http://aperiodic.net/phil/ PGP: 026A27F2 print: D200 5BDB FC4B B24A 9248 9F7A 4322 2D22 026A 27F2 --- -- Your pet monster should be kept in a secure cage from which it cannot escape and into which you cannot accidentally stumble. -- Evil Overlord's Handbook, entry 28 --- -- ___ Talk-us mailing list Talk-us@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk-us
Re: [Talk-us] [OSM-talk] Imagery parallax error in high altitude areas
On 4/9/2012 11:01 PM, Russ Nelson wrote: Nathan Edgars II writes: It's not as bad as it seems. Imagery is adjusted using an elevation dataset. Since this data doesn't (and shouldn't) include buildings and bridges, these appear distorted. You'll also see problems where recent heavy construction has caused changes in topography. Or where the elevation dataset doesn't include a deep canyon, which causes a straight bridge to appear curved. If it's a railroad, you can be pretty sure it isn't. If it's a road bridge, you have to rely on what you saw when you were there. I think this is because the elevation data *does* include the canyon. Since the image was taken at an angle, the bridge appears at a different place in the canyon, and must curve to reach the correct location at the top. Here, for example: http://mapper.acme.com/?ll=38.06661,-81.08022z=16t=O The camera was to the northwest, so the bridge was on a line with the canyon southeast of its actual location. The bridge down in the bottom of the canyon is also curved, but much less so because it's smaller. It's also in essentially the correct place (as seen by comparing to Google's photos and USGS topos). (crossposted to talk-us because who knows when the talk@ mods will let this through) ___ Talk-us mailing list Talk-us@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk-us
[Talk-us] TMC codes
Hi, I notice a new tagging scheme for TMC codes has been proposed (in German only for now..) https://wiki.openstreetmap.org/wiki/DE:Proposed_features/New_TMC_scheme There is a modest discussion going on in tagging@. I'm curious: * Has this topic come up in the US before? * Is TMC LCD data freely available in N-America? With the current focus on remapping (yes we can!) this may not be high on your prio lists, but it's being discussed now and seems to have some traction in Germany, so if there's anything we want to weigh in from a N-American perspective, we should do it now. -- Martijn van Exel ___ Talk-us mailing list Talk-us@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk-us
