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1 silent.cartographer commented Permalink

good one sir! thanks

2 bobleah commented Permalink

@ silent.cartographer - how close did the geolocation map to your physical location?

3 sswonk commented Permalink

It was exact. FF 3.6.4 on Mac OSX 10.6.4 immediately found my exact location. How does it know? I am using a MacBook 3,1 there is no GPS information coming from me. Nutty and a little spooky. Are you reading form prefills, reverse DNS doesn't make sense, it couldn't be that accurate. Please explain how acceptance of the popup sends an exact geographic location, where is the browser getting the coordinates?

4 sswonk commented Permalink

Bob, never mind, I just read this: http://www.mozilla.com/en-US/firefox/geolocation/ - had no idea.

5 bobleah commented Permalink

@ sswonk - Thanks for sharing your experience! <div>&nbsp;</div> Here is my experience: I have 2 PCs, one is a laptop and the other a workstation. Both running off the same linksys, except one is wireless, and the other is tethered. On the PC, my Geolocation is within 2 miles of my physical location... but on my wireless laptop... and it is exact... right to my house! <div>&nbsp;</div> Here is a brief description from the W3C spec on how it works: Common sources of location information include Global Positioning System (GPS) and location inferred from network signals such as IP address, RFID, WiFi and Bluetooth MAC addresses, and GSM/CDMA cell IDs, as well as user input. <div>&nbsp;</div> I will give this app a try from the office next week.. and report my findings.

6 PeterYim commented Permalink

Bob. this is a nice demostration of what HTML 5 can do for maps! cool!

7 kelceyp commented Permalink

I'm in North Sydney and it initially centered me on Sydney which is about 4-5km (~3 miles) south of my current position. <div>&nbsp;</div> Nice demonstration, thanks

8 kelceyp commented Permalink

It's not sticky for me either (not sure if it was meant to be). i.e. If I come back I have to re-scroll the location to my current location again.

9 bobleah commented Permalink

@ kelceyp - Thanks for your report! I didn't make the map sticky, it will attempt to find your current physical location each time you access my blog entry. I find it interesting how some are reporting Geolocation to be very exact... while for others it is simply in proximity to their current location. Especially interesting in my own experience.. with 2 PC's running off of the same linksys. One PC returns my spot on location... the other PC is proximate (within 2 miles) to my location! I would love to hear a report from someone who is mobile.. I suspect that Geolocation fidelity will vary based on the network they are accessing.

10 Richard_Carter commented Permalink

This type of geolocation uses a huge database of routers and the coordinates of those routers. Each router has a wireless adapter, which has a unique MAC address (globally unique); so this database maps MAC addresses to GPS coordinates. Now, when a laptop (or iPod Touch, for example) wants to find its location, it takes the MAC addresses of the nearby wireless access points, and gets their coordinates from this database, which it then uses to approximate its own position (triangulation). In this case, Firefox uses Google's Location Service which indeed uses such a database, combined with IP geolocation (GeoIP) for computers without wireless. <div>&nbsp;</div> So, Bob, your laptop feeds your router's MAC address and any other MAC addresses of other nearby routers into Google, and Google is able to then approximate your location; but your desktop doesn't have wireless, so it simply uses the next best thing, GeoIP, which is usually off by a number of miles. <div>&nbsp;</div> It is amazing to me the completeness of their database of router locations. On the iPod Touch, which of course has no GPS, you can get driving directions from point A to point B, and it will automatically detect where your car is pretty accurately as you drive along the route; it presumably does this by downloading, in advance, all of the routers that are along the route, and then listening for them as you drive down the road.