Apparently, the digitalglobe imagery has been updated. I noticed when I was mapping around Jacmel. I don't know whether the imagery is *better* aligned but it its alignment is obviously different from the former image set (~ 50 m offset?).
-- Karl Am 20.01.2010 05:20, schrieb David Fawcett: > Is there confirmation that the referencing/rectification of the > Digital Globe is good/best. I hate to keep moving features around to > chase the latest imagery. > > David. > > On Tue, Jan 19, 2010 at 4:27 PM, David G. Smith PE PLS > <dsm...@synergist-tech.com> wrote: > >> I had digitized some of those roads and features around Jacmel late last >> week from the DMA mapping, before the DigitalGlobe imagery or other good >> sources were available, with the full anticipation that they would >> eventually be updated via imagery. The bigger value to the DMA maps as I >> saw it is that they had some local cultural information such as POIs and >> place names, as well as basic road network. >> >> >> >> The DMA maps were scanned paper maps, rectified via NYPL MapWarper, no >> surprise that they might be off a tad here and there. >> >> >> >> I have since then been updating via DigitalGlobe, tho there are still some >> areas that need updating. >> >> >> >> So as far as “concern”, there shouldn’t be much, just stick with the more >> current and update the older stuff – though be thoughtful when deleting >> things outright. I think there is still some value to knowing what >> potential road network there may be (even if it’s tracks not well visible >> from the air- I’ve found some that are shown on the DMA maps but which are >> only barely discernible via tree crowns vaguely outlining the road >> underneath) and where there may be potential dwellings, et cetera >> (potentially obscured by tree cover) - I have been designating some of those >> more ambiguous ones (e.g. road network visible in DG imagery, but buildings >> not obvious) as “residential area” as there is probably a reason the roads >> are there. Obviously, if there is no tree cover, there is less ambiguity, >> the road may just be off in another direction, inaccurately placed on the >> DMA maps – worth looking around for it before deleting it outright – I’ve >> found that to be the case in a few instances as well. >> >> >> >> >> >> David G. Smith PE PLS >> >> Synergist Technology Group, Inc. >> >> 570.280.6763 >> >> >> >> From: talk-boun...@openstreetmap.org [mailto:talk-boun...@openstreetmap.org] >> On Behalf Of Al Haraka >> Sent: Tuesday, January 19, 2010 2:59 PM >> To: Brad Neuhauser >> Cc: talk@openstreetmap.org >> Subject: Re: [OSM-talk] Jacmel Haiti, DigitalGlobe Imagery, and Road >> Alignment >> >> >> >> So it seems the consensus is to stick with DG, despite its problems. When >> something better comes along, we start using that. Am I following >> correctly? Some of the old stuff, especially the 1987 map, concerned me. >> >> On Tue, Jan 19, 2010 at 2:48 PM, Brad Neuhauser<brad.neuhau...@gmail.com> >> wrote: >> >> At least that was my assumption. Even if the DG imagery is off, it's >> more up-to-date than the 1987 map, so I moved the roads to align with >> the DG imagery. Much of the city (esp central city, north) has been >> realigned with the DG imagery. I also removed some streets traced >> from the map that were clearly wrong, and tagged some others with the >> fixme tag. Also, see the Street Names page for link to UN maps you >> can use for additional info. >> http://wiki.openstreetmap.org/wiki/WikiProject_Haiti/Street_names >> >> Brad (neuhausr) >> >> On Tue, Jan 19, 2010 at 1:42 PM, Karl Guggisberg >> <karl.guggisb...@guggis.ch> wrote: >> >>> Hi, >>> >>> I have the same problem. Brad Neuhauser said on the crisismapping list >>> that >>> lot of work has been done before digitalglobe was available. In >>> particular, >>> an old CIA map has been used, there are a lot of objects with a source tag >>> refering to it. I've started to delete individual buildings which are >>> obviously badly off. I'm not sure whether the digitalglobe imagery is >>> correctly rectified, thought. Anybody? >>> >>> Regards >>> Karl >>> >>> Am 19.01.2010 20:24, schrieb Al Haraka: >>> >>> All, >>> >>> I understand we are all busy, but I have some Haiti questions. The area >>> around Jacmel in the south appears to be very messy at the moment, and I >>> am >>> only focusing on roads and basic infrastructure. The roads seem very far >>> off, and at times some do not even seem to point to an artifact I can see >>> in >>> the imagery. >>> >>> http://www.openstreetmap.org/?lat=18.22381&lon=-72.52094&zoom=16&layers=B000FTF >>> I have tried cleaning it up using the DigitalGlobe imagery, which I have >>> assumed to be the best. Am I wrong here? What are other people using and >>> what are the current recommendations? Am I doing a bad job or wasting my >>> time aligning the roads if they are this far off? I realize my use of DG >>> may bias me, and I have not taken the time to compare. That being said, I >>> heard it was the most recent and expansive. >>> Sorry for the newbishness here. I just want to help, and I heard Jacmel >>> and >>> all points south will be needed soon. >>> Regards, >>> _AJS >>> >>> -- >>> Alexander J. Stein >>> Cell: (201) 412-9479 >>> Email: alhar...@gmail.com >>> Skype: alexander.j.stein >>> AIM: elduderino6886 >>> >>> _______________________________________________ >>> talk mailing list >>> talk@openstreetmap.org >>> http://lists.openstreetmap.org/listinfo/talk >>> >>> >>> _______________________________________________ >>> talk mailing list >>> talk@openstreetmap.org >>> http://lists.openstreetmap.org/listinfo/talk >>> >>> >>> >> _______________________________________________ >> talk mailing list >> talk@openstreetmap.org >> http://lists.openstreetmap.org/listinfo/talk >> >> >> -- >> Alexander J. Stein >> Cell: (201) 412-9479 >> Email: alhar...@gmail.com >> Skype: alexander.j.stein >> AIM: elduderino6886 >> >> _______________________________________________ >> talk mailing list >> talk@openstreetmap.org >> http://lists.openstreetmap.org/listinfo/talk >> >> >> > _______________________________________________ > talk mailing list > talk@openstreetmap.org > http://lists.openstreetmap.org/listinfo/talk > > _______________________________________________ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk
