Okay, its been 24 hours since loading Android 2.2 (JP2) on my O2 UK Galaxy S. JP1 was really slow.
Like many others, my original GPS results were crap at best, with dropouts, superman effects, etc.
My i9000 has had no changes made to it. I started fresh with JP2. I loaded My Tracks and GPS Test.
In GPS Test, the screen response of Satellites coming and going is much improved. The Satellites shown appear to be much more stable. It still will not lock on to more than 8 Satellites at a time and will not lock onto any Satellite with a signal below 20db just like previously.
I have done ten test tracks with My Track averaging 10 miles or more over a large variety of road types from country lanes to highways or motorways as we call them.
Eight of the tracks were clean and quite accurate. For the first track I was in a hurry so did not have a good solid GPS lock when I started. When I reviewed the track afterward, I noticed that the mobile did not get a good lock until about 7 minutes into the trip. This part of the trip involved lots of overhead trees. The rest of the trip had considerably less tree cover.
Now what is odd about this is that my TOMTOM GO720 will do exactly the same thing if I start a trip without a good GPS lock. The TOMTOM will take about 5 minutes to lock if it is moving. Sitting still, it is about a minute.
The weather today is complete cloud cover and yesterday totally clear.
This mornings trip, I purposely parked under an area with total tree cover part way into the route. Its like being in a lit tunnel. The GPS did not lose lock after a minute and did not jump around like Superman. A good fix was acquired as soon a I came out from under the trees.
I have not had any complete dropouts like previously. My tracks are all complete.
I also did a walking track last night in the neighbourhood. I took a 1/2 mile slow stroll and the track stayed at 16.7 foot accuracy for almost the whole time. I did stop at one point to observe some house construction and moved randomly within a 20 foot area. This is the only point where the accuracy decreased to 50 foot. The moment I started moving forward in a straight line, accuracy came back to 16.7 feet.
So in summary, the GPS likes to be moving forward for accuracy, clouds don't seem to affect it and heavy tree cover does.