On Dec 5, 2009, at 4:02, "David ``Smith''" <vidthe...@gmail.com> wrote:
> On Fri, Dec 4, 2009 at 7:47 PM, Scott Atwood <scott.roy.atw...@gmail.com > > wrote: >> Offshore islets can probably be mapped via satellite imagery. > > It's common practice for providers of aerial/satellite imagery such as > Yahoo to mask out actual coverage of oceans and large lakes with a > generic "ocean" texture that is meant to look "better" than actual > photographic data. So if it's small and not very close to the > mainland, don't count on it showing up in the Yahoo imagery. Ah! Thanks for that explanation! I had already noticed some of the more isolated islets in the northwest Hawaiian islands were mysteriously missing from the Yahoo images and aren't in the PGS data either. However, I was mostly referring to the numerous small islets within a few hundred meters of shore. Most of these don't seem to be in PGS, but so appear in the Yahoo images, though not necessarily at a very high resolution. The GIS data should give good coverage of these islets near the main islands. -Scott _______________________________________________ Talk-us mailing list Talk-us@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk-us