All Things GPS

[SamsungVibrant]

Interesting videos. The first one was on this forum before, but not sure if everyone has seen it.

YouTube - Samsung Epic 4G for Sprint - GPS Test (vs. Captivate)!

The second video confuses me, he has a vibrant with some hack, what gps hack for the vibrant? The other phone is his new Epic. It looks like even with the hack he is talking about, he mentions the vibrate doesn't locate him that well.

YouTube - Samsung Epic 4G GPS FAIL

 

[jayhawksean]

With assistance off, I have 8 in view, 8 in use. Accuracy of 98' though.

that's nearly exactly what i had on mine here in Grand Rapids, MI.

most of the 8 were yellow and a few went to very light green with a 1 or 2 also sometimes going orange.

 

[plainbrad]

I'm really interested to hear from prior smart-phone Android users, because these users will be able to make a direct comparison of the GPS to prior phones.

Using GPS with the towers not enables it says I have birds visible with 7 in use. Found 4 and was using 4 in about 3-4 seconds. This is from my apartment which is very old and usually has poor connection to the outside world.

 

[SamsungVibrant]

Using GPS with the towers not enables it says I have birds visible with 7 in use. Found 4 and was using 4 in about 3-4 seconds. This is from my apartment which is very old and usually has poor connection to the outside world.

great, good to know. when you have time, mind doing a real world test in a car. going for a drive, throw in some curve balls like when navigation says turn right, turn left, and lets see how good it re-routes. a long drive whenever you have time. also make sure wireless networks is off. thank you for the good news.

 

[hokie gti]

Using the free GPS test, I had 10 in view, 8 in use with a 98.4' accuracy. Use Wireless networks is disabled.

Here is a My Tracks map. Zoom and and check out the details. This consisted of mostly highway driving with speeds ranging from 0 - 70mph.

Track 1 - Google Maps

In this map, we walked around a park on a fixed path. There shouldn't have been much deviation on the track, but as you can see there was a bit of separation.

Track 2 - Google Maps

Is it pin point accurate? Not really, but the results are good enough to work with.

 

[adelmundo]

Yeah that 98.4' number is consistent with all of us. I got it again today using GPS test and locking onto 8 sats 8 viewed. It's really weird many of us are all getting the magic 98 number.

 

[boomerbubba]

The second video confuses me, he has a vibrant with some hack, what gps hack for the vibrant? The other phone is his new Epic. It looks like even with the hack he is talking about, he mentions the vibrate doesn't locate him that well.

I saw that video when the reviewer first posted it. I surmise that "the GPS hack" on the Vibrant he referred to was either one of the commonly memed "fixes" using the hidden menu to set the configuration to enable MS Assisted or MS Based aGPS modes, or the popular hacker Eugene's custom ROM that did essentially the same thing in script code. (Neither was really a fix, but enabling aGPS did help in this situation, getting a satellite lock indoors.)

Quite obviously, the Epic could not get a lock indoors with what I assume is a stock setting with network assist disabled. But that does not really surprise me. I will forgive such performance indoors. What I care about is the actual satellite performance outdoors -- both the locking performance and the accuracy.

 

[Adrift]

Hey Folks,

I posted this in the other GPS thread. This is my "My Tracks" track I recorded earlier tonight after I got off work. aGPS is off, as is "Google Use My Location" or whatnot. This is only proof of my phones GPS, also note I didnt know you can set "My Tracks" to be more accurate and to record your track faster, as such, my "Os" are boxy/triangular.

Gps Test At Shopping Center - Google Maps

Please note that, on my device, GPS Test reports 10-12 sats in view/use and accuracy of 98 feet. This seems to show accuracy is much better than that, at least on my Epic.

 

[boomerbubba]

Using the free GPS test, I had 10 in view, 8 in use with a 98.4' accuracy. Use Wireless networks is disabled.

Here is a My Tracks map. Zoom and and check out the details. This consisted of mostly highway driving with speeds ranging from 0 - 70mph.

Track 1 - Google Maps

In this map, we walked around a park on a fixed path. There shouldn't have been much deviation on the track, but as you can see there was a bit of separation.

Track 2 - Google Maps

Is it pin point accurate? Not really, but the results are good enough to work with.

To me, these results show several things:

1) It is yet another example of the new "98 feet" bug that has cropped up uniquely on the Epic. We don't really know what all the effects of this bug are, or what conditions trigger it. But obviously something is broken.

2) The highway driving track looks good, but this does not prove very much. Similar tracks often look good on other Galaxy S phones with problems, and can be explained by the smoothing and interpolationg of the underlying coordinate data. To its credit, the phone did seem to track accurately on the freeway cloverleaf ramp. A more demanding test would be over lots of curves and turns, including some long stops. So this is qualified good news.

3) The walking track is also consistent with some walking track performance on other Galaxy S phones that have GPS problems. Without the high-speed smoothing effects of a vehicle, the tracking does get lost significantly, as you note. This is why walking tracks are more demanding tests, and why some users of apps such as athletic run tracking complain their Galaxy GPS can be quite useless compared to other smartphones. So I would call this track moderately bad news.

 

[Adrift]

3) The walking track is also consistent with some walking track performance on other Galaxy S phones that have GPS problems. Without the high-speed smoothing effects of a vehicle, the tracking does get lost significantly, as you note. This is why walking tracks are more demanding tests, and why some users of apps such as athletic run tracking complain their Galaxy GPS can be quite useless compared to other smartphones. So I would call this track moderately bad news.

Can you please comment on my sample? I would like to know your analysis.

 

[boomerbubba]

Can you please comment on my sample? I would like to know your analysis.

Just found that in the other thread and commented there. From your test it does look like "it works" to me. Yes, that is good news indeed.

 

[5Strong]

I am not having problems with the GPS. Although the accuracy shown by GPS Test is 98.4ft, when I switch to Maps or use Tracks it looks to be dead on. This is the case outside in the backyard or inside the house.

I agree this is a location problem, it is the location of the person using the device that is the problem. I am a serious runner and I use a Garmin 405 GPS unit for all of my runs. For those that are not familiar, this is a wrist watch sized GPS unit. I also travel a great deal for business. I can tell you that in some cities my GPS is flawless and in others it keeps asking me if I am inside, when anyone could tell by looking at me run that I am on the beach with clear skies! Very frustrating, but none the less a fact. At home, in Las Vegas, Sat coverage is great and always reliable.

 

[Aero1]

To me, these results show several things:

1) It is yet another example of the new "98 feet" bug that has cropped up uniquely on the Epic. We don't really know what all the effects of this bug are, or what conditions trigger it. But obviously something is broken.

2) The highway driving track looks good, but this does not prove very much. Similar tracks often look good on other Galaxy S phones with problems, and can be explained by the smoothing and interpolationg of the underlying coordinate data. To its credit, the phone did seem to track accurately on the freeway cloverleaf ramp. A more demanding test would be over lots of curves and turns, including some long stops. So this is qualified good news.

3) The walking track is also consistent with some walking track performance on other Galaxy S phones that have GPS problems. Without the high-speed smoothing effects of a vehicle, the tracking does get lost significantly, as you note. This is why walking tracks are more demanding tests, and why some users of apps such as athletic run tracking complain their Galaxy GPS can be quite useless compared to other smartphones. So I would call this track moderately bad news.

seeing the same thing. not total failure but much worse than the current crop of smartphones if one ignores the other galaxy s handsets.

 

[boomerbubba]

seeing the same thing. not total failure but much worse than the current crop of smartphones if one ignores the other galaxy s handsets.

I don't think I said anything like "much worse than the current crop of smartphoneg" with regard to those particular results. They just weren't conclusive.

Also, Adrift's walking track above, which is probably the most demanding test of the Epic's accuracy I have seen so far, looks very good. And since it also exhibits the "98 feet" bug in the satellite lock as shown by GPS Test, but still has very good tracking accuracy in My Tracks, that is encouraging. (However, the imputed value of 98 feet is certainly a bug at some level. I can imagine that some other apps might read the same bogus value and be fooled into erroneously treating the accuracy circle as large. Perhaps that explains some of the anecdotal reports of problems.)

I now have my own Epic in hand, and I am initializing it today. Over the next few days I am traveling, but I hope to be able to do some side-by-side testing with my venerable G1.

 

[Torq]

Initially I thought GPS on my Epic was working fine; a bit less accurate than is ideal, even compared to other phones, but basically working.

What I've seen after a day of usage however is that periodically I have to restart the entire phone to get it to lock on to any satellites at all. Then it'll work fine for a while again, and at some point thereafter it will still see satellites but won't lock on to any and consequently needs to be rebooted before I can use GPS again.

This would seem to be a software/GPS stack issue rather than a hardware fault, but it is very annoying.

Anyone else seeing the same thing?

 

[robl45]

i tested mine at lunch and it locked on fine. I charged it all night at my house and it was on with wifi on. was locking satellites yesterday and today. 10 in view, 10 locked.

Initially I thought GPS on my Epic was working fine; a bit less accurate than is ideal, even compared to other phones, but basically working.

What I've seen after a day of usage however is that periodically I have to restart the entire phone to get it to lock on to any satellites at all. Then it'll work fine for a while again, and at some point thereafter it will still see satellites but won't lock on to any and consequently needs to be rebooted before I can use GPS again.

This would seem to be a software/GPS stack issue rather than a hardware fault, but it is very annoying.

Anyone else seeing the same thing?

 

[blueatlanta]

mine worked fine. locked first time within 30 meters.

 

[SamsungVibrant]

i tested mine at lunch and it locked on fine. I charged it all night at my house and it was on with wifi on. was locking satellites yesterday and today. 10 in view, 10 locked.

Did you actually go for a drive at lunch, or you just turned it on and saw locks. People should actually test it in the real world, meaning go for a nice long drive, with "USE WIRELESS NETWORKS" TURNED OFF.

Really challange the GPS with a nice intensive drive, throw some loops, make a left instead of a right, see how responisve the GPS is in re-routing.

Let us know.

 

[Adrift]

Did you actually go for a drive at lunch, or you just turned it on and saw locks. People should actually test it in the real world, meaning go for a nice long drive, with "USE WIRELESS NETWORKS" TURNED OFF.

Really challange the GPS with a nice intensive drive, throw some loops, make a left instead of a right, see how responisve the GPS is in re-routing.

Let us know.

SamsungVibrant, considering that you are among the most determined on this forum to find out if Epic GPS works, would you mind commenting on my results?

 

[SamsungVibrant]

SamsungVibrant, considering that you are among the most determined on this forum to find out if Epic GPS works, would you mind commenting on my results?

Are you talking about the "my tracks" you posted? Well I thank you for posting that, however, and I say this with all do respect, and I'm not trying to start a war here, that didn't prove to me that the accuracy is correct. I will explain my rationale. Lets say the accuracy is off by 100ft, you can still track out the word it "works", like you did, but everything could possibly just be offset 100ft. Does that make sense? If I'm wrong please correct me, but when I saw what you posted, first thing I thought was "well everything could just be offset 98 ft"

Look I just want my update already! So I can test this already. I'm confused I'm reading positive comments like the ones you posted, then there are also equall number of people who say their GPS isn't performing as it should. I wish I could test this on my own, I want the update!

 

[RickJ]

Are you talking about the "my tracks" you posted? Well I thank you for posting that, however, and I say this with all do respect, and I'm not trying to start a war here, that didn't prove to me that the accuracy is correct. I will explain my rationale. Lets say the accuracy is off by 100ft, you can still track out the word it "works", like you did, but everything could possibly just be offset 100ft. Does that make sense? If I'm wrong please correct me, but when I saw what you posted, first thing I thought was "well everything could just be offset 98 ft"

Look I just want my update already! So I can test this already. I'm confused I'm reading positive comments like the ones you posted, then there are also equall number of people who say their GPS isn't performing as it should. I wish I could test this on my own, I want the update!

Being a 100' off woulda probably put him inside on of the shops lol. Id bet that his unit is working more than acceptable, based on that and the other statements from the complex he walked.

For the bad news though Samsung Epic:Anyone else having a problem with GPS... I hadnt seen this posted around here yet

**Note the reference to dg27 update

 

[Adrift]

SV, I totally understand what you saying about the off by 100' thing. However, I can assure you that it was accurate enough to put me in the right parking spaces in the parking lot. If you put it in satellite view, which is what I used in My Tracks, you can see each individual space. On my track, where you see the grassy divider, when I was on that in real life I was exactly there in my tracks. It was off by a 3 feet on one spot because I remember I was dirctly on a parking space line, and my cursor was in the spac3e itself, however a few seconds later it was back track with me.

By the way I work at the big store beside "dustie's" or whatever, directly after work I went out and and made the track. The parking lot acting like a giant grid was an unintended benifit as it aided in me being able to see just how accurate the GPS is on my device. I can say from my test last night it is easily accurate to within 3 feet.

 

[boomerbubba]

@Adrift, SamsungVibrant:

My theory of the moment is that the actual accuracy of the track and the imputed accuracy that is erroneously reported are not directly related. IIRC, these two data elements come from two different listeners in the Android programming interface, each fed by low-level drivers from the GPS chip. There may be other apps where the imputed accuracy is significant, but I don't think My Tracks cares. It may be visible as a circle around the cursor in My Tracks, as it is in some navigation apps, but the center point is apparently what is being captured.

BTW, I suspect the "98.4 feet" bug is really a 30 meter bug, a nice round number that some programmer managed to store as a literal value instead of a dynamic variable. (30 meters = 98.425 feet.)

 

[Torq]

Continued to test the GPS throughout the day. I am still seeing an issue where it sees satellites, even reports their SNR, but will not lock onto them unless I reboot.

Once I reboot, it's okay for a while.

Out of interest, after going through the reboot, I didn't run any other apps (I don't have much installed at this point).

I still don't think this is a hardware issue, though I suppose it's possible.

I do know it's not environmental; every other GPS-equipped device I have locks on in seconds (and that's several dedicated GPS receivers, and a brace of phones).

Incidentally, if you're getting accuracy better than about 33 ft its luck/coincidence (plot falls within margin of error). You need WAAS support which, to my knowledge, no phone has, just to get accuracy down to 10 feet reliably.

 

[RickJ]

I may well be mistaken but as I understand it WAAS is not needed for horizontal accuracy. Most current cell phones will get you in under 10ft of accuracy, dedicated gps units even better.