- From: Andrei Popescu <andreip@google.com>
- Date: Fri, 27 Jun 2008 20:34:37 +0100
- To: "Erik Wilde" <dret@berkeley.edu>
- Cc: public-geolocation@w3c.org
Hi Erik, On Fri, Jun 27, 2008 at 12:35 AM, Erik Wilde <dret@berkeley.edu> wrote: > hello. > >> - Mentioned that we default to WGS84 for the coordinate system and >> added an issue about supporting other geodetic systems. > > wgs84 is not good enough as a reference system for altitude. altitude can > also be measured in meters above geoids, which is the more accurate way of > measuring altitude (egm96 is the most common model for that). and it can be > measured using barometric measurements, which also is an important way of > measuring altitude. we really should have some people looking at that who > know this stuff from the inside out, i am a web person and my knowledge is > not all that solid... > Sure. I added a note saying that maybe we should consider allowing a difference reference system to be used for altitude. I'm just not sure how common such implementations will be. Maybe I'm wrong. > http://www.avionicswest.com/PDFiles/alt2.pdf#page=6 > >> I'd be very grateful if you could have another look and let me know >> what you think, especially if there are any fundamental changes that >> are still needed (things around the overall API design, things that >> should be addressed or should be left out, etc). > > i still think that http://dev.w3.org/geo/api/spec-source.html#position is > just too limited in its model of location. a location can be a lat/long pair > of coordinates, but it also can be something else, like the identification > of a city or a state or some other place-oriented location concept. this > becomes critically important in the light of privacy issues, when a mobile > user wants to get location-based services without having to disclose his > coordinates. if he can still say "i am in berkeley" or "i am in california", > this opens a much wider range of possible scenarios than a purely spatial > location concept. > I understand your point of view here and I also think that the URI idea is very interesting. However, since absolutely everybody seems to agree that this spec should consider spatial coordinates, my proposal is to start with those and agree on an API that makes sense in this context. Many thanks, Andrei
Received on Friday, 27 June 2008 19:35:14 UTC