You may have noticed the update on our Epic 4G review from yesterday where we lauded the fact that Samsung seemed to have fixed the GPS problem plaguing every other Galaxy S flavor released thus far, but it turns out there are actually two distinct issues. One has a fix -- sort of -- while the other is hopefully what we're going to get next month. Here are the two failure modes, based on what we know so far:
  • "Use wireless networks" is now turned off by default, but even with it on, the phone may be slow or unable to determine even a rough location. Originally, we'd believed this was the only problem. Samsung tells us that it's a new Google mandate that Android devices be shipped with the "use wireless networks" option disabled, which means you're relying on traditional GPS alone to determine your location -- a lost cause indoors, in urban canyons, or under dense tree cover. Indeed, we discovered it was turned off on our Captivate, Vibrant, and Epic 4G after fresh hard resets, and there's no indication to the user that it's probably in their best interest to enable it; we're accustomed to being presented with the option during account setup on other Android devices, but it doesn't happen here. After enabling it from settings, we found that both the Captivate and Epic 4G were able to get our location with 1,000 to 1,500-meter accuracy practically immediately in Google Maps, though the Vibrant still never came through; it had the weakest signal of the three, which may have accounted for that (though it never dropped the signal altogether).
  • The regular GPS circuitry and software aren't doing their job. Cell tower triangulation and WiFi location database services like Skyhook only take you so far -- at the end of the day, you still need to tune in to the birds a few thousand miles up to figure out precisely where you are. All Galaxy S models seem to be having trouble turning GPS reception into coordinates, even when the phone is able to see four or more satellites in view (four is the minimum you normally need for a precise, three-dimensional lock). In some cases, resetting the phone apparently helps, but it ceases to work again after a day or two of use. To our knowledge, none of the homebrew fixes out there have been able to solve this part of the problem perfectly and permanently. The Captivate and Vibrant are both affected by this one; we're not sure on the Epic, but we're working to nail it down.
What this means for you: for now, simply make sure you have "Use wireless networks" checked in your Galaxy S's settings under the "Location & security" menu. It won't get you the most reliable, precise location you should be entitled to, but it's a start -- and next month's round of firmware updates should hopefully take us the rest of the way.

[Thanks, Carl]