Just for the heck of it, I set my 205W to show me the satellite view while driving to customer's today. With a good lock on 10 to 11 sats I was seeing between 11 & 20 feet. What's your best?
I have found that the accuracy is determined by the speed I am going. The slower the better it gets.
It is harder for the unit to keep up at higher speeds.
has gotten as low as 6' with the antenna and a clear sky.
The Kenwood/Garmin in dash unit in my car always gets 10' accuracy and locks in nearly all the sats in a few seconds.
I have found that it can easily determine if I'm on the highway or on the service road just 20' away running alongside the highway.
My other portable Garmin units would get in the 11-20' range normally but took longer to lock in the sats.
Best accuracy I've gotten with a smartphone without tweaks (HTC T-Mobile G2) is around 18ft (with 8 satellites received). Which is actually pretty good, considering this is a smartphone (though admittedly a smartphone with a red-hot integral GPS capable of reception in a basement!).
With a program specifically designed to do GPS averaging (named GPS Averaging, logically enough, in the Android Market) I've gotten as good as 10 feet, but it should be noted this is a specialised tool pretty much designed for planting geocaches and hence is cheating a bit.
I'll also note (for purpose of comparison) that this is not in "clear sky" conditions; as is per usual in my part of the country this time of year, it's been perpetually overcast when it's not actively raining or snowing so I've not had a good chance to see how it behaves in optimal conditions yet. Seeing as I can get 10-11 satellites even in cloudy conditions (and have gotten 8-9 satellites indoors in a basement), I expect it'd behave better in clear-sky conditions; we'll soon see the first time it's not cruddy outside...
My best (at home) has been 15ft. My worst has been 220ft, during a thunderstorm.
Is getting 7 meters in my livingroom right now... vs my 765t's 32ft.
I usually 3 meters (10 feet).
Please see http://www.poi-factory.com/node/1838
from 3and1/2 years ago
My zumo 660 locks in very fast and the few times I've looked it is always < 20 feet, except when I'm down in the city. Looked at the gps the other day and saw myself driving in the middle of the river. I wondered if I should turn the steering wheel.
Tall building stink!
My 255W is not as accurate as yours..It seems to be closer and farther to actual distance randomly!
Is about as good as I've got.
I get the same accuracy
At 55mph my 1490 shows 10 feet most of the time. In my west window at home shows 20 to 70 feet. When I show trip log & leave it in the window overnight, the track wanders around and shows up to 100 feet away from the house. In my east window, it always shows 10 or 12 feet. I don't know why.
Finally did get the chance to try out the T-Mobile G2's GPS in optimal "open sky" conditions--just to make sure it wasn't cheating by pulling in ephemerides for the satellites via AGPS (which is actually how smartphones can usually lock on), I set the phone to airplane mode except for the GPS.
A FIX WITHIN TWO METERS (around 6 1/2 feet) and average fixes around 3-4 meters (10-15 feet-ish) without AGPS, without fancy tricks, without averaging.
WITH an averaging tool used in geocaching, I got the averaged fix under a meter (but again, that's cheating because that's averaging)...
...but a 2-meter fix is impressive.
Dear HTC: I am surprised and pleased how well the G2 locks onto GPS satellites (apparently like a pit bull!). Thank you and please do continue in this direction.
30 Seconds in time & 10 foot Accuracy..!!
My Nuvi 1300 WT GPS has been sitting on a shelf in my computer room/office for the past three plus months now. I just picked it up and walked out front door into the middle of the country road that runs past the house. Turned it on, waited for the splash screen.. and after the main screen came on I pressed the upper left corner of the screen and started counting.
It took between 20 to 30 seconds to acquire all 10 satellites. Sats #3,6,13,16,19 & 20 were all above 75%.. while #'s 20,25,30 & 31 were at 100%. It also showed a accuracy of 10 feet.
By the time one and a half to two minutes went by I had a accuracy of between 3 to 4 feet with all satellites showing 100%. I would guess it would depend on the time of day or night.. and the weather conditions.
I'll have to check how mine does outside the truck. (When it warms up a bit)
Routinely 10 ft while on the highway, 55 to 85 mph. Will very rarely pop up a little bit from this, to perhaps 13 feet.
Dash disc mount, no external antenna, and not dependent on using FM traffic receiver (which I don't believe contributes to position fix like my old DGPS receiver).
Smartphone? Well, I'm testing out the android averaging application listed above, just for kicks. Thanks!
about 15 ft with a 755t
3 meters = 9.84252 (just having fun...no ill intent!)
I remember an extensive debate a few years back about GPS speed vs. odometer speed.
Is GPS accuracy really a function of speed?
I guess you could say it is a function of speed if you refer to the speed of light. Accuracy depends on the number of satellites you receive and the timing difference between them. So, if the speed of light is affected, then the accuracy would be affected.
When outside, I usually have around 10-foot accuracy on my 1450.
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