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Garmin 60CX showing wandering tracks I never made. Why?


Petermgr
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Now it's starting to make ME laugh--reading users justify an UNACCEPTABLE problem simply becuase they own that unit. As if to convince yourself that you made the right choice and didn't let impulse at all influence your buying decision.

 

Think back....way back.

 

I'm not trying to insult anyone or state the 60/76 is a bad line on GPSrs. I didn't know it would wander until I owned myself. But in my opinion, this problem is unacceptable because it is fixable. Other units don't do it, and other brands with 99% the accuracy and reception don't do it. Modern Lowrances might have track smoothing or whatever; I've never heard of it. My OLD one had 'Pinning' which eliminated it AND the reception was 99% as good at the 60/76 - it was just much slower to get the lock. When pinning was on, the unit would not register a speed or direction when stationary but it would show a bearing to target. It was amazing for geocaching although you wouldn't think so until you used it.

My 76 wanders in the best of conditions - in open fields and on the water. When I first used it for a geocache in Ottawa, I was almost tempted to return to my car and get my GM100 because the wandering of the 76 while on foot was so bad as to make the 'Track up' feature unusable because of how annoying it was to watch the map rotate. Sure, if I was hunting Geocaches in the basement of someone's house or in canyons where other GPSrs couldn't get a lock, I'd prefer using the 60/76, but 99% of the time I am in areas where reception isn't an issue.

 

I just believe this characterisitic deserves voicing a loud concern over since it would appear to be something that is fixable in future generations.

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GreatCanadian, you may have as many issues with my statements as you like, but I still claim it's due to lack of understanding of the rather complex math that goes on inside your navigator.

 

Navteq claims their detailed maps to be accurate to within 10 meters, by the way.

 

Claim what you will, but as for understanding, you are obviously choosing to not understand MY point. I know exactly what you are talking about, and understand exactly what happens when a vista cx and a 60cx are taken through a canyon, and why a vista would show a nice looking, but actually inaccurate track. If you read my post, you would realize that i was travelling open terrain. There is no excuse for a $400 GPS to lay down a crappy track in open terrain. And you're telling me that it's doing so because it's so great a picking up signals that it picks up even the weak ones that throw the track off!! That makes no sense. If it can't interpret it's signals better than that, then it is not reliable. And it does seem that it is NOT all the 60's and 76's doing this. But it also appears that there are quite a few more than me having this problem. I don't thing it's good enough for a $400 GPS. I need my GPS to take me through a narrow opening when in my boat to get to the harbor where my Dad's cabin is. I do that with the Legend C. I NEVER NEVER NEVER use the 60cx for this, as it could very likely be 50 to 60 meters or more off!!! That puts me aground. My Legend C is trusty enough to ALWAYS LEAD ME THROUGH SAFELY.

 

I guess my point is this. If I have an extra few minutes to wait for accuracy to find a bucket of toys hidden in the woods, I guess the 60cx is most definitely the best out there at this. If I need instant accuracy to guide me through that harbor inlet, then the track on the 60cx is NOT the one I would trust at all. At least not on MY 60cx. Do you really think that that is acceptable in a $400 unit? A wandering track could be deadly. Again, I am talking about open terrain. (By the way, my 60cx is showing an EPE of anywhere from 2 to 6 meters most of the time, even when nowhere near that.)

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Now it's starting to make ME laugh--reading users justify an UNACCEPTABLE problem simply becuase they own that unit. As if to convince yourself that you made the right choice and didn't let impulse at all influence your buying decision.

 

Think back....way back.

 

I'm not trying to insult anyone or state the 60/76 is a bad line on GPSrs. I didn't know it would wander until I owned myself. But in my opinion, this problem is unacceptable because it is fixable. Other units don't do it, and other brands with 99% the accuracy and reception don't do it. Modern Lowrances might have track smoothing or whatever; I've never heard of it. My OLD one had 'Pinning' which eliminated it AND the reception was 99% as good at the 60/76 - it was just much slower to get the lock. When pinning was on, the unit would not register a speed or direction when stationary but it would show a bearing to target. It was amazing for geocaching although you wouldn't think so until you used it.

My 76 wanders in the best of conditions - in open fields and on the water. When I first used it for a geocache in Ottawa, I was almost tempted to return to my car and get my GM100 because the wandering of the 76 while on foot was so bad as to make the 'Track up' feature unusable because of how annoying it was to watch the map rotate. Sure, if I was hunting Geocaches in the basement of someone's house or in canyons where other GPSrs couldn't get a lock, I'd prefer using the 60/76, but 99% of the time I am in areas where reception isn't an issue.

 

I just believe this characterisitic deserves voicing a loud concern over since it would appear to be something that is fixable in future generations.

 

I couldn't agree more.

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The point you make about "Pinning". Read this:

"This approach of course also comes at a price. If you use such low signal levels, you will also get some pretty bad signals that will make your position jump around quite a bit when you are stationary or moving slowly. SiRF's answer against that is called “Static Navigation” and it is a feature of the chipset that freezes your position when you are moving slower than 4 km/h . Position changes will only be registered when the difference exceeds 50 meters. As a result when you walk slowly your position seems to be frozen and it updates only every once in a while."

 

So their answer was like your "Pinning". Problem is static navagation is no navagation at all. It is my understanding that this feature is no longer in place due to complaints. Thus you have jumpy tracks during low signal moments. Static navagation just make you think the unit is stable when it isn't. Which is better? some crappy position or none at all? One or the other really is not right or wrong, just a different way of doing things. On the older units like my Garmin 12 or my old Garmin Map76 it is my understanding that when it lost a signal (a higher level signal) it lost signal, and filled in track when it reaquired. With the sirf models they tried to fool you but now they just give you the truth about what they aren't sure of with weak position.

 

Quit being nasty about ego here. It's stupid. Just help us all figure out what is best and how it works. I love many of the feature on my 60cx. I often wish I had my Map76 back because I feel accuracy is a percetage better on it then my 60cx. Especially on tracking and odometer.

 

So I'm trying to figure out how to improve my 60cx on these points. Right now I'm thinking I'll try taking the setting down from "most often" on the tracking to "Normal" and see it that helps in low signal areas and multi-path areas.

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One correction on my above post. On my older units when you were driving along and went through a tunnel, obviously there was no signal, but the units would assume you were going the same speed and direction for aways. It still used what data it had for a short time, and then lost signal. I believe this may be in part the data it was still using from the sats that were still considered good, and the speed filters function, which you see when you come to a sudden stop. The speed reading still says you are moveing and then drops off in a few seconds.

 

I think this is the kiliam(sp?) filter? Is that right apersson850?

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So am I to understand that I with the 60CX I should have cleared my tracking immediately before I started walking around my block in order to get a less cluttered screen? That even standing by my front door, getting the dog's collar and leash on, could have allowed time for the 60CX to apply tracks from ghost or bounced signals? And again, would I have noticed this behavior more so because my house has aluminum siding?

 

Peter

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That is true with any unit. Sirf or not. You "may" pick up enough bounced signal to throw your track position off in odd directions. Usually due to nearby walls or trees. I assume (my guess) that this requires more that a minimal number of bounced sat signals to do so.

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This approach of course also comes at a price. If you use such low signal levels, you will also get some pretty bad signals that will make your position jump around quite a bit when you are stationary or moving slowly. SiRF's answer against that is called “Static Navigation” and it is a feature of the chipset that freezes your position when you are moving slower than 4 km/h . Position changes will only be registered when the difference exceeds 50 meters. As a result when you walk slowly your position seems to be frozen and it updates only every once in a while.

 

I use Sirf Star III in a Pocket PC using Mapopolis program. I've noticed that happens sometimes with what you're decribing and I've compensated by stopping the GPS acquisition and then turning it back on. I do this specifically when hiding a cache to get a more accurate reading for the coordinates.

 

Just curious. How do cachers who hide with 60cs's and other Sirf Star III receivers handle this? Do they find similar problem?

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It would appear I've become lost a little bit as to which qwirk with the units we're talking about. The Original post showed what I interpreted to be track wandering that occured when the unit was first fired up inside a building. The recorded track as the unit was carried around the block looked pretty reasonable to me, not knowing of course the exact course he took. Had the track been cleared once the unit had settled down, and prior to starting the short journey, I think the results would probably have been acceptable. This assumption is of course based on just looking at the picture, without the track data itself, you can't look determine when the problem occured, how fast the event was etc.

 

Regarding units wandering, especially when first fired up, I've found they all tend to do that, especially if the unit was moved to a different location from when it was last turned on. Other things that have a large effect include the orientation of the unit. For instance, I've found that if you hold a quad antenna unit horizontal instead of vertical you more than double the positional error.

 

For those doubting that the etrex's or other units wander, set up the unit to record at a timed interval of say 5 seconds, maybe a little more, then put the unit on flat surface and let it record for awhile. If you do this side by side with a 60 series, I think you'll find you get pretty comperable results.

 

That said, much of the discussion seems to have drifted to cronic types of errors, which I've found the sirf based units to be far more prone to than other garmin units. (The older magellan units often suffered like this as well). The sirf units will often be off by a considerable offset with the error remaining for long periods of time. For an example of the sort of error I'm referring too, see: Angles Landing track This track was recorded by a sportrak on a out and back trail hike, but I have several similar and even much worse with sirf units

 

In comparison, the etrex for example will often rapidly dance around, then either loose reception or bounce back to a more accurate postion. These flyers or richochets are much easier to edit out of a track than the significant offset you often get with the 60. Myself being an avid hiker that often gets into some pretty difficult terrain, I much prefer the etrex quirks. I don't want the unit feeding me inaccurate info and would much prefer it give me nothing at all when in doubt. For my auto units though, where lock to road takes care of most of the glitches the Sirf solution is fine or even preferable.

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This approach of course also comes at a price. If you use such low signal levels, you will also get some pretty bad signals that will make your position jump around quite a bit when you are stationary or moving slowly. SiRF's answer against that is called “Static Navigation” and it is a feature of the chipset that freezes your position when you are moving slower than 4 km/h . Position changes will only be registered when the difference exceeds 50 meters. As a result when you walk slowly your position seems to be frozen and it updates only every once in a while.

 

I use Sirf Star III in a Pocket PC using Mapopolis program. I've noticed that happens sometimes with what you're decribing and I've compensated by stopping the GPS acquisition and then turning it back on. I do this specifically when hiding a cache to get a more accurate reading for the coordinates.

 

Just curious. How do cachers who hide with 60cs's and other Sirf Star III receivers handle this? Do they find similar problem?

No. I think they have disabled this feature in our units.

Many people here are useing model numbers loosely. The 76cx and csx have the sirf, the 60cx and 60cxs have the chip. All other 76 and 60 models do not.

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In comparison, the etrex for example will often rapidly dance around, then either loose reception or bounce back to a more accurate postion. These flyers or richochets are much easier to edit out of a track than the significant offset you often get with the 60. Myself being an avid hiker that often gets into some pretty difficult terrain, I much prefer the etrex quirks. I don't want the unit feeding me inaccurate info and would much prefer it give me nothing at all when in doubt. For my auto units though, where lock to road takes care of most of the glitches the Sirf solution is fine or even preferable.

I agree. A couple of days ago I had an extreme example of this with my 60cx on a forested mountian hike. The 4 mile trail registered as over 7 miles on my odometer and track log. Looking at the track log I went around in circles a lot on my way up the mountain. Obviously the 60cx was recording everything it took in includeing multipath errors. I'm thinking the solution in this case is to lengthen the track recording points to longer time or distance or "less often".

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The point you make about "Pinning". Read this:

"This approach of course also comes at a price. If you use such low signal levels, you will also get some pretty bad signals that will make your position jump around quite a bit when you are stationary or moving slowly. SiRF's answer against that is called “Static Navigation” and it is a feature of the chipset that freezes your position when you are moving slower than 4 km/h . Position changes will only be registered when the difference exceeds 50 meters. As a result when you walk slowly your position seems to be frozen and it updates only every once in a while."

 

So, how do I enable this on my 76?

 

So their answer was like your "Pinning". Problem is static navagation is no navagation at all. It is my understanding that this feature is no longer in place due to complaints. Thus you have jumpy tracks during low signal moments. Static navagation just make you think the unit is stable when it isn't. Which is better? some crappy position or none at all?

 

I'm sorry, but I still say you are being subjective and not 'hearing' what I am saying.

Two units, side-by-side being used while on foot. Signal strength IS NOT an issue here - at least not in my examples - because it happens 99% of the time; it is speed, not location (granted, location can pronounce the effect)related.

During a standstill, one unit -with 'Pinning' set to 'ON' shows zero movement while the other unit consitently shows and records erratic movement and speed. On the first unit the bearing to target remains unchanged, on the second, it constantly changes.

Begin walking and the unit with the Pinning function continues to show no speed BUT periodically updates the change in position and heading [accurately] and the bearing to target changes accordingly. The other unit without pinning becomes even more erratic with map orientation and zoom levels possibly changing UNLESS a fast paced walk is achieved.

 

To me, the more desirable of the two observations is obvious. When I used my old unit with pinning, although it never showed a speed, the distance travelled and heading/bearing were almost always accurately displayed and the recorded track was entirely accurate without the star pattern of wandering even though the unit said I had a speed of zero. If however, I turned off pinning, I would see the same result as the Garmin - maybe less actually since it ignored the weaker signals and had a slower update period.

 

The point of 'too many complaints' is completely moot. It's a toggle function. Don't like it? Turn it off.

 

Once again the real issue is being ignored: useability. Who cares about the science behind it. I'd rather just hear an admission from a 60CSx user that IT IS an undersireable effect and that there has been shown to be a solution to it in other models or mfg's.

 

Again, I will say that I am happy and impressed with my Garmin but sure, there are some things on it I miss from the Lowrance. I give myself credit for being a long time Lowrance user and crossing over to Garmin - sometimes it's hard to change from what you are used to. But, if I was a die hard geo-cacher, as many here are and it's their sole purpose for buying a GPS, I WOULD NOT recommend the 60/76 line.

Edited by MajBach
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I use Sirf Star III in a Pocket PC using Mapopolis program. I've noticed that happens sometimes with what you're decribing and I've compensated by stopping the GPS acquisition and then turning it back on. I do this specifically when hiding a cache to get a more accurate reading for the coordinates.

 

"Indeed, this feature was also present in the XTrac chipset, and it caused some grief with the pedestrians and Geocachers. Fortunately this feature can be switched off with a tool called SiRFDemo. Guillaume over at GpsPasSion has written a brief tutorial on how to use SiRFDemo - http://www.gpspassion.com/forumsen/topic.asp?TOPIC_ID=25575 (you need a Bluetooth enabled PC for that) "

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I'm sorry, but I still say you are being subjective and not 'hearing' what I am saying.

Two units, side-by-side being used while on foot. Signal strength IS NOT an issue here - at least not in my examples - because it happens 99% of the time; it is speed, not location (granted, location can pronounce the effect)related.

During a standstill, one unit -with 'Pinning' set to 'ON' shows zero movement while the other unit consitently shows and records erratic movement and speed. On the first unit the bearing to target remains unchanged, on the second, it constantly changes.

Begin walking and the unit with the Pinning function continues to show no speed BUT periodically updates the change in position and heading [accurately] and the bearing to target changes accordingly. The other unit without pinning becomes even more erratic with map orientation and zoom levels possibly changing UNLESS a fast paced walk is achieved.

 

To me, the more desirable of the two observations is obvious. When I used my old unit with pinning, although it never showed a speed, the distance travelled and heading/bearing were almost always accurately displayed and the recorded track was entirely accurate without the star pattern of wandering even though the unit said I had a speed of zero. If however, I turned off pinning, I would see the same result as the Garmin - maybe less actually since it ignored the weaker signals and had a slower update period.

 

The point of 'too many complaints' is completely moot. It's a toggle function. Don't like it? Turn it off.

 

Once again the real issue is being ignored: useability. Who cares about the science behind it. I'd rather just hear an admission from a 60CSx user that IT IS an undersireable effect and that there has been shown to be a solution to it in other models or mfg's.

 

Again, I will say that I am happy and impressed with my Garmin but sure, there are some things on it I miss from the Lowrance. I give myself credit for being a long time Lowrance user and crossing over to Garmin - sometimes it's hard to change from what you are used to. But, if I was a die hard geo-cacher, as many here are and it's their sole purpose for buying a GPS, I WOULD NOT recommend the 60/76 line.

 

I wonder how pinning works (I do care how things work). It must be somewhat like "lock on road" but I don't see how it could give accurate bearing from a change position. Anyway, the concept here is that you trade off's. No position or lousy position (or phony position) which is more desirable? Depends on the situation. In the woods I want to at least have some idea where I am. On the street or at sea I want to exactly where I am. If it was totally undesirable to have "some" idea of where I am I would say so, but there are times when it helps. Geocaching in the NW I often run into this. My track going up that mountain was all over the place but always close to my current position. My friends with the 60cs model usually had no clue where they were.

 

If I am still not getting the point, sorry. If you think the mfg"rs can solve everything, they can't. New technology is always stepping forward but always presents new problems.

 

Now as to phony poisitons. That is how Sirf claims to be able to acquire sats faster (they used to but I don't think they do anymore cause they had to solve some glitches), They incorperate synthetic empheris (did I spell that right, (sat position data)) into the chip. It guesses where they are. I think the sirf chip is an advancement but I don't trust their methods of advancement.

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I wonder how pinning works (I do care how things work). It must be somewhat like "lock on road" but I don't see how it could give accurate bearing from a change position. Anyway, the concept here is that you trade off's. No position or lousy position (or phony position) which is more desirable? Depends on the situation. In the woods I want to at least have some idea where I am. On the street or at sea I want to exactly where I am. If it was totally undesirable to have "some" idea of where I am I would say so, but there are times when it helps. Geocaching in the NW I often run into this. My track going up that mountain was all over the place but always close to my current position. My friends with the 60cs model usually had no clue where they were.

 

 

Don't know if this tells you anything you don't already know. Straight from the manual. Remeber the days of SA? *SIGH*

POSITION PINNING

When using a GPS receiver at extremely low speeds, it can have trouble

determining your course over ground, or direction you’re travelling. This is

due in large part to SA, or selective availability. SA is small inaccuracies

purposefully put into the GPS satellite’s signal by the government. This

cause wide variations in the track display and other navigation displays

when using the unit at slow speeds.

If you’re using this receiver without DGPS and stop, the position pinning

feature locks the present position indicator on the plotter until you’ve moved

a short distance or exceed a very slow speed. This prevents the “wandering”

plot trail seen when you’re stopped with position pinning turned off.

This also affects the navigational displays.

The easiest way to see the effects of S/A is to stand still with the GPS

receiver turned on and watch your plot trail with position pinning turned

off. You’ll see the present position change, speed increase and decrease,

and a random plot trail on the plotter’s screen.

If you wish to turn the position pinning feature off, press the MENU key,

then highlight the “GPS Setup” label and press the right arrow key. Now

highlight the “Pinning” label. Finally, press the left arrow key.

Edited by MajBach
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Ok, so it looks like it lock the display until you move enough again. I can see this in the day of SA. That SA was an annoyance. So from what I see Sirf was copying this with Static Navagation because their low quality signal variations caused a SA effect. Again a good argument against the sirf chip as not every signal is worth using or helpful (unless you can't get a fix any other way).

Generally, when in the open and acquiring good quality signals, the sirf does about as good as any other GPS. I just trust the others a bit more in some areas.

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I've got a 60CSX. I've had about 1/2 dozen different Garmins 60csx, 60cs, vista, Map III, !2 probably more). I think the 60CSX is extremely accurate on the track other than the problem with it wandering when it is in the house. The problem in the first picture is obviously wondering inside the house. The easy solution to that is clear the track log when you go outside and when you want to start creating a track. Or you can delete the first points in mapsource. Then you have a clean track. One thing that helps when you are not moving or in bad reception is to hold the GPS upright. It gets better reception like that then when it is laying flat.

 

For my track logs, I set it for most often as that gives much more accurate tracks (and use the active log-never save the track on the GPS as you lose data). I also always have WAAS enabled. I have GPSed at least one hundred trails like that and make custom maps. After I make the trail map from the track file, I can go back to the same place in a month or so. Then you can see how accurate the track files are. Normally I have to zoom in to at least 120 feet before I can detect any deviation from the trail on the GPS. That tells me the track file is extremely accurate or I would be seeing much greater discrepancies in the track and the trail made from the previous track. Generally, the tracks will be closer to a trail I made with a track file than the streets in City Navigator. Generally the devation from the orginal track file is around 20 feet or less. I have also got track data from the Forest Service made with survey grade GPS and made map files from it. When I go and walk the trails, you have to zoom into about 120 feet before you see any difference. I have had may other GPSs and have saved tracks from the older GPSs. When I revisit the areas with my 60CSX, many times there are huge differences.

 

While there are issues when you are standing still or have it sitting in your house, when you are out walking, biking, driving with the 60CSX, it is making an extremely accurate track.

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PS About a month ago, I walked through the urban canyon of the Loop in Downtown Chicago. While I don't go there often, in the past I got spotty reception at best and when I did many times I was not in the right place. With my 60CSX I never lost reception. But there were obvious problems that I figured where caused by the signal bouncing on the buildings. My track zigzaged from the streets to the buildings. While sometimes it showed me in the middle of the street or in a building, I was always shown in the correct block. The only time I have ever had any serious accuracy problems was one time in Olympic National Park in a deep canyon and huge trees above me. I never lost reception, but sometimes it had me in the wrong place.

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