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Compass accuracy


FoxyLadyBird
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Previously our phones had perfect accuracy.

 

That's extremely unlikely, the best you can get with a handheld device is about 10-15 feet, the phone might have been reporting better accuracy but it's probably misleading. If your GPS is reporting 16 feet that's reasonable, and you should expect it to be that good or better. A quarter of a mile is really bad and I've never had a GPS get a lock and be that bad, the worst I've ever seen was about 75 feet in the woods, any worse than that and it would lose the lock and not work.

 

There's nothing you can do to alter the accuracy of the GPS other than make sure it has a clear view of the sky, and a view of the horizon will be even better. Believe it or not sticking it on your head helps! Using it under trees will also detrimentally affect the signal.

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I suspect that you are not actually using GPS at all if your accuracy is that poor.

Most likely, you phone is triangulating using cell tower positions rather than using GPS position.

 

Are you certain the phone has a GPS receiver and it is turned on? Many phones have the GPS turned off by default since it consumes battery power at a significant rate.

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uhhh... the OP said compass accuracy on a new phone. Are we all sure there is a handheld GPS involved in this question?

 

Yeah...phones.

 

Does anyone know how to set accuracy on the compass? My son and I are new to Geocaching. Previously our phones had perfect accuracy. We have gotten new phones. Now our accuracy is between 16 feet and a quarter of a mile. Thank you.

 

And yes, in the phone app, the compass DOES tell distance in addition to direction.

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uhhh... the OP said compass accuracy on a new phone. Are we all sure there is a handheld GPS involved in this question?

 

Yeah...phones.

 

Does anyone know how to set accuracy on the compass? My son and I are new to Geocaching. Previously our phones had perfect accuracy. We have gotten new phones. Now our accuracy is between 16 feet and a quarter of a mile. Thank you.

 

And yes, in the phone app, the compass DOES tell distance in addition to direction.

Maybe the "compass view", but not the compass. Compasses, by definition, only provide direction.

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uhhh... the OP said compass accuracy on a new phone. Are we all sure there is a handheld GPS involved in this question?

 

Yeah...phones.

 

Does anyone know how to set accuracy on the compass? My son and I are new to Geocaching. Previously our phones had perfect accuracy. We have gotten new phones. Now our accuracy is between 16 feet and a quarter of a mile. Thank you.

 

And yes, in the phone app, the compass DOES tell distance in addition to direction.

Maybe the "compass view", but not the compass. Compasses, by definition, only provide direction.

 

Oh dear lord...now you're just quibbling. Everyone KNOWS a straight-up, bare-bones compass only tells direction. It's the smartphone app that's being discussed here.

 

iPhone GC "Compass" (and yes, that's the exact thing you select...not "Compass View", not "Compass Mode"...just "Compass"):

 

geocache_app3.jpg

Edited by J Grouchy
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Does anyone know how to set accuracy on the compass? My son and I are new to Geocaching. Previously our phones had perfect accuracy. We have gotten new phones. Now our accuracy is between 16 feet and a quarter of a mile. Thank you.

 

To be fair, the OP didn't mention anything about iPhones or any particular app. They only mentioned "new phone" and "compass". We don't know if they have iPhones or some other type, the official Groundspeak app or some other, or in fact any Geocaching app at all. For all we know they may just be using the basic Compass app that comes with the phone.

 

OP, if you can provide some specifics about what device you are using and what app, we can offer better assistance.

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Does anyone know how to set accuracy on the compass? My son and I are new to Geocaching. Previously our phones had perfect accuracy. We have gotten new phones. Now our accuracy is between 16 feet and a quarter of a mile. Thank you.

 

To be fair, the OP didn't mention anything about iPhones or any particular app. They only mentioned "new phone" and "compass". We don't know if they have iPhones or some other type, the official Groundspeak app or some other, or in fact any Geocaching app at all. For all we know they may just be using the basic Compass app that comes with the phone.

 

OP, if you can provide some specifics about what device you are using and what app, we can offer better assistance.

 

True...but any of the geocaching apps iOS and Android, both API and non-API have the distance feature. I don't know of any "basic compass app that comes with the phone"...

Obviously, there are several that one can download...

Edited by J Grouchy
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I think AZcachemeister hit the nail on the head. This device must have a GPSr to get 15 feet accuracy, but it sounds like when it can't get a GPS signal it's using transmitter triangulation and at that point it goes down to 200 feet. I doubt there's anything the OP can do about this other than make sure the phone has a clear view of the sky whenever possible.

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uhhh... the OP said compass accuracy on a new phone. Are we all sure there is a handheld GPS involved in this question?

 

Yeah...phones.

 

Does anyone know how to set accuracy on the compass? My son and I are new to Geocaching. Previously our phones had perfect accuracy. We have gotten new phones. Now our accuracy is between 16 feet and a quarter of a mile. Thank you.

 

And yes, in the phone app, the compass DOES tell distance in addition to direction.

Maybe the "compass view", but not the compass. Compasses, by definition, only provide direction.

 

Oh dear lord...now you're just quibbling. Everyone KNOWS a straight-up, bare-bones compass only tells direction. It's the smartphone app that's being discussed here.

 

iPhone GC "Compass" (and yes, that's the exact thing you select...not "Compass View", not "Compass Mode"...just "Compass"):

 

geocache_app3.jpg

 

It's not quibbling. The compass in a smart phone is not something one can actually see (without taking apart the phone). Instead, you can view a graphical representation of the data provided by the internal compass. The same screen that is displaying the graphical representation of the data provided by the compass is also displaying distance, current and destination location information (as lat/long coordinates) and accuracy and that data is obtained from the internal GPS. The fact that GS decided to label the screen "Compass" does not make it a compass.

 

 

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uhhh... the OP said compass accuracy on a new phone. Are we all sure there is a handheld GPS involved in this question?

 

Yeah...phones.

 

Does anyone know how to set accuracy on the compass? My son and I are new to Geocaching. Previously our phones had perfect accuracy. We have gotten new phones. Now our accuracy is between 16 feet and a quarter of a mile. Thank you.

 

And yes, in the phone app, the compass DOES tell distance in addition to direction.

Maybe the "compass view", but not the compass. Compasses, by definition, only provide direction.

 

Oh dear lord...now you're just quibbling. Everyone KNOWS a straight-up, bare-bones compass only tells direction. It's the smartphone app that's being discussed here.

 

iPhone GC "Compass" (and yes, that's the exact thing you select...not "Compass View", not "Compass Mode"...just "Compass"):

 

geocache_app3.jpg

 

It's not quibbling. The compass in a smart phone is not something one can actually see (without taking apart the phone). Instead, you can view a graphical representation of the data provided by the internal compass. The same screen that is displaying the graphical representation of the data provided by the compass is also displaying distance, current and destination location information (as lat/long coordinates) and accuracy and that data is obtained from the internal GPS. The fact that GS decided to label the screen "Compass" does not make it a compass.

 

Yeah...it's quibbling because you made an argument out of something that nobody was arguing about. Everyone knows what "compass" refers to when talking about geocaching apps, what data is presented. Your clarifying it was pretty much completely unnecessary.

 

As for the 164 accuracy thing...that's ridiculous, but not typical in my experience. While my phone certainly isn't as accurate as most, if not all, current GPSr devices, it pretty much always gets me to the right spot and usually within 15 - 20 feet at the outside. More typical is within 10-12 feet. Not bad, really. Only problem is getting it to be steady. Usually it will point to different places, sometimes while I'm standing still, varying its output while I remain stationary.

Edited by J Grouchy
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I know exactly what the OP is talking about as I had the same problem. I had the original droid and it was pretty accurate. Then I upgraded to the droid bionic and it was all over the place. It was horrible. Now I have the samsung galaxy and it is remarkably dead on.

There is a slight chance you might not have one of the I think 3 ways it can tell your position on but I doubt it. Some phones just have better gps's built into them. Just have to walk away and then back and try to figure it out. Keeping moving seemed to help as once you stop it jumps all over. You will have to learn your new phones or get a galaxy. :)

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uhhh... the OP said compass accuracy on a new phone. Are we all sure there is a handheld GPS involved in this question?

 

Yeah...phones.

 

Does anyone know how to set accuracy on the compass? My son and I are new to Geocaching. Previously our phones had perfect accuracy. We have gotten new phones. Now our accuracy is between 16 feet and a quarter of a mile. Thank you.

 

And yes, in the phone app, the compass DOES tell distance in addition to direction.

Maybe the "compass view", but not the compass. Compasses, by definition, only provide direction.

 

Oh dear lord...now you're just quibbling. Everyone KNOWS a straight-up, bare-bones compass only tells direction. It's the smartphone app that's being discussed here.

 

iPhone GC "Compass" (and yes, that's the exact thing you select...not "Compass View", not "Compass Mode"...just "Compass"):

 

geocache_app3.jpg

 

He's not "quibbling", he's being accurate.

Edited by nelamvr6
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Ok, you guys. As I mentioned, we are new at Geocaching. I was actually apprehensive about posting because I had seen the direction many of the posts took while I was scanning them. There is a lot to learn, and I am still trying to figure out the various acronyms. I didn't know where to look for the replies to my original post, so I posted another today; then stumbled into these responses when I went to my profile to make changes. I appreciate the responses and realize that I did not give enough information.

I had never had good accuracy on my phone. It was most always 16 to 150 feet and even up. My son's said "0" ft. which appears to me to mean it is right on, and it most always lead him right to the cache. My phone is a Motorola, android version 2.3.7, model #XT555C. My sons new phone is a Samsung Galaxy S4, android version 4.2.2. It is within the Geocaching app where one chooses from: Directions, Maps, or Compass that we have the problem. We choose directions to drive to it; then use the compass while walking to pin it down. When it is 16 feet, I can deal with it, although since my son has experienced much better, he doesn't want to deal with it. He wants the accuracy back. I confess i would rather have the accurate reading, too. Now neither of us knows whether the Geocaching app has this built in or whether it uses whatever compass app is on our phones.

There appears to be a great deal of knowledge out there. We would appreciate any help to figure this out. As newbys, there is so much that we do not know. Thanks in advance for your help.

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Please forgive me. I don't know how I posted it twice. I guess I must have it "post" twice, although I would swear I didn't. Lol! It must have been a senior moment. I tried to get rid of one, but all it did was leave an empty box and the two posts. So I decided to apologize for my ineptness in this empty box.

Edited by FoxyLadyBird
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Yes, there was (is?) confusion and discussion there.

 

After looking at it (the screenshot was especially helpful), I see what you are trying to address.

 

The "accuracy" that the unit (as a whole -- not simply the compass) is displaying is in reality Estimated Positional Error (EPE).

It does not mean necessarily that the device is off by that much. It is only an ESTIMATED possibility of positional error.

This comes about because of a variety of things -- signal strength, most importantly; number(s) of satellites used to compute position; the satellite constellation the unit is receiving from; antenna efficiency; signal blockage and other, less tangible factors.

 

Although one would hope for a better EPE, that number given really does not affect the true "accuracy" of the unit. Most any unit, be it a dedicated GPSr or a GPS-equipped phone has that function, whether it displays such or not.

Also, it varies (sometimes greatly) based upon those given variables.

 

Have you actually found that this matter directly affects your ability to find geocaches? Or did you simply notice it and pose the question about your device being "inaccurate"? I ask because if you have not tried to find caches since you noticed that, you probably should try to -- it may well not affect your ability to find caches because the EPE displaying such a high number.

 

This question has come up before, and I am sure it will come up again -- mostly from dedicated GPSr users. The fact that your app compiles and shows unrelated info in a single screen is what caused that confusion.

 

Again, what you see is not a true "accuracy" issue. I have never used a phone for caching. I have used three models/makes of GPSr units, and they have all displayed EPE readings from 0 to something like 256 ft. It has never stopped me (us) from successfully finding what we were looking for.

 

Hope that helps, even if just a tiny bit.

 

EDIT to add: you could ask for a moderator to close your newly asked question in the other forum (by posting a request for such in that thread).

Edited by Gitchee-Gummee
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Pretty technical question.

 

In Android devices accuracy is defined as the radius of 68% confidence. In other words, if you draw a circle centered at this location's latitude and longitude, and with a radius equal to the accuracy, then there is a 68% probability that the true location is inside the circle.

 

If the device does not compute this accuracy then 0 is returned. If your son's phone is reporting 0 ft. accuracy it just means that the 68% confidence radius was not (or could not be) computed. It doesn't mean his phone is any better than yours.

 

On a phone the accuracy can vary considerably. In part this has to do with the current configuration of sattelites in the sky relative to your position. It also has to do with how the phone determines your position when it first trying to get the GPS location. It takes a while, even with a dedicated GPS unit, to get a "fix" from at least four satellites and then to get additional information from the satellites to correct certain errors. During this time, phones use other methods to estimate your location - such as the cell towers it can communcate with or the wireless networks it can detect. These location estimates are very innacurate. Generally, if you leave the phone in GPS mode for a while the accuracy will improve. (It will also use up your battery faster).

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Ok, you guys. As I mentioned, we are new at Geocaching. I was actually apprehensive about posting because I had seen the direction many of the posts took while I was scanning them. There is a lot to learn, and I am still trying to figure out the various acronyms. I didn't know where to look for the replies to my original post, so I posted another today; then stumbled into these responses when I went to my profile to make changes. I appreciate the responses and realize that I did not give enough information.

I had never had good accuracy on my phone. It was most always 16 to 150 feet and even up. My son's said "0" ft. which appears to me to mean it is right on, and it most always lead him right to the cache. My phone is a Motorola, android version 2.3.7, model #XT555C. My sons new phone is a Samsung Galaxy S4, android version 4.2.2. It is within the Geocaching app where one chooses from: Directions, Maps, or Compass that we have the problem. We choose directions to drive to it; then use the compass while walking to pin it down. When it is 16 feet, I can deal with it, although since my son has experienced much better, he doesn't want to deal with it. He wants the accuracy back. I confess i would rather have the accurate reading, too. Now neither of us knows whether the Geocaching app has this built in or whether it uses whatever compass app is on our phones.

There appears to be a great deal of knowledge out there. We would appreciate any help to figure this out. As newbys, there is so much that we do not know. Thanks in advance for your help.

 

Thanks for the detailed information. In general, the more detail you can provide when asking a question in these forums the better the answers you'll receive.

 

Although it was suggested that you "calibrate your GPS", a GPS generally doesn't require calibration. More likely, what they were describing was calibrating the screen and/or accellerometer (the piece of hardware in the phone the detects the orientation of your phone as you're holding it). That won't improve accuracy. The GPS in your phone, or in a handheld GPS receiver is basically just a receiver of satellite signals. Accuracy is basically a function of the number of satellite (and their orientation) the GPS is receiving. With an optimal satellite configuration, you're still constrained by the number signals you are receiving and some of them can be blocked by tree cover and buildings. You'd be surprised at how many places there are in Manhattan where accuracy is reported to be very high or there aren't even enough signals to calculate your position and that's all because the tall buildings are blocking most of the satellite signals. The number that the device as "Accuracy" is just an probability estimate. Essentially, it tells you that there is a 50% probability that the reported position is within a specific radius. That also means that there is a 50% probability that it is outside that radius, but doesn't tell how far outside that radius it might be.

 

More importantly, when navigating to a cache, all your GPS can do is attempt to navigate you from your current reported position to a destination (i.e. the lat/long coordinates for a waypoint/cache). Of course, the published coordinates were captured with a GPS with it's own accuracy constraints so even your reported position matches the coordinates provided by the cache owner, that doesn't mean you'll be standing right next to the cache. As a general practice, use the GPS to get "close" (which could be 20 feet or much more) then started for looking for places where someone might hide a container. If you follow your GPS trying to get it to read zero feet (or meters) you might find you're walking in circles only to look up and see a large log 30 feet away where the cache is most likely hidden.

 

So how *can* you improve accuracy? Sometimes it's as simple as how you're holding your phone, removing the phone from it's case, or even holding it over your head. If you had a jet pack you could fly up 100 feet off the ground to get a clear view of more satellites but I suppose that's not very practical. Basically, you need to give the antenna that is used by the internal GPS chip the best chance to receive as many satellite signals as possible.

 

 

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Please forgive me. I don't know how I posted it twice. I guess I must have it "post" twice, although I would swear I didn't. Lol! It must have been a senior moment. I tried to get rid of one, but all it did was leave an empty box and the two posts. So I decided to apologize for my ineptness in this empty box.

 

Don't worry about it. Even grizzled forum veterans occasionally make duplicate posts. Unfortunately, the forum software does not allow us to delete our own post, so instead you'll see a lot of "Sorry. Duplicate post" here.

 

 

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