compass

[iwanceri]

do i need an electrnic compass for geo caching, have been looking at the vista hcx.

[+kallt_kaffe]

do i need an electrnic compass for geo caching, have been looking at the vista hcx.

 

Read this thread, then decide: http://forums.Groundspeak.com/GC/index.php?showtopic=214662

 

I went with a Legend HCx and saved some money.

[+DonB]

do i need an electrnic compass for geo caching, have been looking at the vista hcx.

Depends on who you talk to. Personally I wouldn't buy another GPS without one.

[+twolpert]

Is it necessary? No. Is it nice to have? Does depend on whom you ask. Some people swear by them -- and some swear at them. The advantage is that the pointer is updated even when you are standing still. And it's updated based on the direction you are facing. The down side is that the pointer may (depending on the unit and local reception conditions) swing wildly when you are near the cache. If that happens, it's worse than not having the compass -- but you can always disable it temporarily.

[+Walts Hunting]

I usually turn mine off. I have had problems with mine on my Oregon. Just yesterday (for some reason was turned on) and I was under tree cover close to a cache when the arrow turned 180 degrees I turned around and walked aways and it turned 180 again. Turned if off walked a few steps and got a correct arrow. Don't know why but that has been a problem under cover a few times.

[iwanceri]

thanks everyone i will get the one with the compass i think.

[+Prime Suspect]

I usually turn mine off. I have had problems with mine on my Oregon. Just yesterday (for some reason was turned on) and I was under tree cover close to a cache when the arrow turned 180 degrees I turned around and walked aways and it turned 180 again. Turned if off walked a few steps and got a correct arrow. Don't know why but that has been a problem under cover a few times.

The arrow is not the compass. What you were seeing is GPS error, not compass error.

[+wrkn2mch]

I only have my vista hcx for about two weeks now and I turn it off while moving until about twenty feet away then i turn the compass on and follow to the location......so far that way seems the best but i still have more to learn about it.

Joe

[guggie]

Is it necessary? No. Is it nice to have? Does depend on whom you ask. Some people swear by them -- and some swear at them. The advantage is that the pointer is updated even when you are standing still. And it's updated based on the direction you are facing. The down side is that the pointer may (depending on the unit and local reception conditions) swing wildly when you are near the cache. If that happens, it's worse than not having the compass -- but you can always disable it temporarily.

 

As one other poster said, the arrow you are talking about is NOT the compass arrow. You are talking about a course pointer that is dependent on the GPS signal. There is no way that an electronic compass arrow can "vary widely" when you are near the cache unless the cache area has a magnetic anomaly nearby it.

[guggie]

thanks everyone i will get the one with the compass i think.

 

Go with the Vista HCx. It's great!

[FanMan]

I only have my vista hcx for about two weeks now and I turn it off while moving until about twenty feet away then i turn the compass on and follow to the location......so far that way seems the best but i still have more to learn about it.

You can set your GPS to switch from compass to heading at a selectable speed, so it doesn't use the compas until, say, you're moving less than 1 mph for 5 seconds, or whatever you choose.

 

The compas does suck down the batteries, though, so I always leave it turned off, turn it on briefly to check the direction, then turn it off again.

[+Cache'n Hounds]

I cache without a compass I have a Magellan Triton 1500 and it doesn't have it. I have not found a need for one yet but then again i don't have to many caches under my belt. I have been deep in the woods and had to pull out the external antenna. I see how it would be nice but most of them i have played with the ones in the stores on various gpsr and they aren't that good. Get a good regular compass ( none digital) this should help you if you feel the need to use a compass that is what i do and most of the time it stays in my bag. Just my thoughts on this.

[+TotemLake]

Is it necessary? No. Is it nice to have? Does depend on whom you ask. Some people swear by them -- and some swear at them. The advantage is that the pointer is updated even when you are standing still. And it's updated based on the direction you are facing. The down side is that the pointer may (depending on the unit and local reception conditions) swing wildly when you are near the cache. If that happens, it's worse than not having the compass -- but you can always disable it temporarily.

 

As one other poster said, the arrow you are talking about is NOT the compass arrow. You are talking about a course pointer that is dependent on the GPS signal. There is no way that an electronic compass arrow can "vary widely" when you are near the cache unless the cache area has a magnetic anomaly nearby it.

 

Actually it will. The calculated coordinates are still based on GPS and the compass is going to point where the GPS thinks the coordinates are. Just because you're standing still deosn't mean the coordinates don't bounce around based on the varying geometric position of the satellites. I saw this happen all the time with the MeriPlat and see it happen with the PN-40.

 

When you get close enough the compass does jump around on you, it still is time to put it away. You're within ground zero.

 

The underlying difference is if you lost satellite signal, the compass will point in the direction of the last known location of the coordinates at the time of signal loss. It is, however, up to you to estimate your distance when this happens.

Edited March 9, 2009 by TotemLake

[+julianh]

The compas does suck down the batteries, though, so I always leave it turned off, turn it on briefly to check the direction, then turn it off again.

Are you sure? When I tested the current drain on my Summit HC, the difference in current drain was negligible when I turned the compass on and off.

 

My battery test results are here:

 

http://forums.Groundspeak.com/GC/index.php...l=battery+life#

 

(You will see that others also report negligible battery drain on various models when the compass is turned on.)

 

I now have my compass turned on all the time, and my battery life is pretty much in line with or even better than Garmin's advertised 14 hours for this unit. (I use Varta 2,100 mAh "Ready2Use" Hybrid NiMhs.)

Edited March 9, 2009 by julianh

[+TotemLake]

The compas does suck down the batteries, though, so I always leave it turned off, turn it on briefly to check the direction, then turn it off again.

Are you sure? When I tested the current drain on my Summit HC, the difference in current drain was negligible when I turned the compass on and off.

 

My battery test results are here:

 

http://forums.Groundspeak.com/GC/index.php...l=battery+life#

 

(You will see that others also report negligible battery drain on various models when the compass is turned on.)

 

I now have my compass turned on all the time, and my battery life is pretty much in line with or even better than Garmin's advertised 14 hours for this unit. (I use Varta 2,100 mAh "Ready2Use" Hybrid NiMhs.)

I concur with this. I never saw a big difference to cause me to turn off the compass on the MeriPlat and I still don't with the PN-40.

[guggie]

Is it necessary? No. Is it nice to have? Does depend on whom you ask. Some people swear by them -- and some swear at them. The advantage is that the pointer is updated even when you are standing still. And it's updated based on the direction you are facing. The down side is that the pointer may (depending on the unit and local reception conditions) swing wildly when you are near the cache. If that happens, it's worse than not having the compass -- but you can always disable it temporarily.

 

As one other poster said, the arrow you are talking about is NOT the compass arrow. You are talking about a course pointer that is dependent on the GPS signal. There is no way that an electronic compass arrow can "vary widely" when you are near the cache unless the cache area has a magnetic anomaly nearby it.

 

Actually it will. The calculated coordinates are still based on GPS and the compass is going to point where the GPS thinks the coordinates are. Just because you're standing still doesn't mean the coordinates don't bounce around based on the varying geometric position of the satellites. I saw this happen all the time with the MeriPlat and see it happen with the PN-40.

 

When you get close enough the compass does jump around on you, it still is time to put it away. You're within ground zero.

 

The underlying difference is if you lost satellite signal, the compass will point in the direction of the last known location of the coordinates at the time of signal loss. It is, however, up to you to estimate your distance when this happens.

 

Nope. You're confused. You are not describing the behavior of a true electronic compass as in the HCx. Compass don't "go to a point". They point in a direction based on the magnetic pole. The arrow's action may bounce and shift around because of the nature of the GPS signal (drift, multipath, etc.) , but the underlying compass card certainly does not. The compass card is purely sensitive to the surrounding magnetic field when the compass is on. If the compass is turned off, then behavior is totally different, more as you describe. I agree that the bearing arrow points in many different directions when you are close to the cache, but the compass card does not shift more than a few degrees at most. In summary, the Vista HCx displays a screen with a bearing arrow overlying a compass card when navigating to a cache. The arrow moves entirely independent of the compass card. The card behaves like any ordinary magnetic compass. It points north, period (when turned on).

Edited March 10, 2009 by guggie

[+julianh]

As one other poster said, the arrow you are talking about is NOT the compass arrow. You are talking about a course pointer that is dependent on the GPS signal. There is no way that an electronic compass arrow can "vary widely" when you are near the cache unless the cache area has a magnetic anomaly nearby it.

Actually it will. The calculated coordinates are still based on GPS and the compass is going to point where the GPS thinks the coordinates are. Just because you're standing still deosn't mean the coordinates don't bounce around based on the varying geometric position of the satellites. I saw this happen all the time with the MeriPlat and see it happen with the PN-40.

 

When you get close enough the compass does jump around on you, it still is time to put it away. You're within ground zero.

There is a fundamental confusion here. On GPSrs with an active electronic compass, there are TWO distinct and independent "pointing devices" - the "compass ring" and the "red pointer". The compass does not swing around, but the red pointer may.

 

Provided it is calibrated and used properly (i.e. held level etc), the compass ring will always point NSEW, and will NOT swing around unless you yourself are turning around.

 

The red pointer however points in the computed direction from your current computed GPS location to the waypoint coordinates (which are "fixed"). As your computed location can "drift" several metres in real time (due to the vagaries of GPS reception, partial blockages, shielding from your own body, internal "smoothing" algorithms which can take a while to notice you have stopped moving, etc), the computed distance to your destination can also vary rapidly when you are within a few metres, and the computed direction to your destination can also "swing" when the distance to your destination is comparable to the amount of real-time "GPS drift". Allowing the GPSr to "settle" for minute or two can get it to "lock" to a more static computed location, and this can reduce the amount of swinging of the red pointer.

 

Bottom line - when you are within a few metres of your destination, it is time to stop looking at the red pointer, and start looking at the ground!

 

Hope this helps!

Edited March 10, 2009 by julianh

[FanMan]

Re compass and bettery drain: I haven't had my 60CSx for long enough to say for sure, but I know that the effect on battery life was dramatic when I was using the Geko 301. I could have sworn there was something about that in the manual, but I jsut looked and couldn't find it. I have seen it mentioned on a number of other websites, though.

 

Of course if you have it set to switch from compass to track when you're moving, then the compass isn't on all the time, so battery life should improve.

Edited March 10, 2009 by FanMan

[+TotemLake]

Is it necessary? No. Is it nice to have? Does depend on whom you ask. Some people swear by them -- and some swear at them. The advantage is that the pointer is updated even when you are standing still. And it's updated based on the direction you are facing. The down side is that the pointer may (depending on the unit and local reception conditions) swing wildly when you are near the cache. If that happens, it's worse than not having the compass -- but you can always disable it temporarily.

 

As one other poster said, the arrow you are talking about is NOT the compass arrow. You are talking about a course pointer that is dependent on the GPS signal. There is no way that an electronic compass arrow can "vary widely" when you are near the cache unless the cache area has a magnetic anomaly nearby it.

 

Actually it will. The calculated coordinates are still based on GPS and the compass is going to point where the GPS thinks the coordinates are. Just because you're standing still doesn't mean the coordinates don't bounce around based on the varying geometric position of the satellites. I saw this happen all the time with the MeriPlat and see it happen with the PN-40.

 

When you get close enough the compass does jump around on you, it still is time to put it away. You're within ground zero.

 

The underlying difference is if you lost satellite signal, the compass will point in the direction of the last known location of the coordinates at the time of signal loss. It is, however, up to you to estimate your distance when this happens.

 

Nope. You're confused. You are not describing the behavior of a true electronic compass as in the HCx. Compass don't "go to a point". They point in a direction based on the magnetic pole. The arrow's action may bounce and shift around because of the nature of the GPS signal (drift, multipath, etc.) , but the underlying compass card certainly does not. The compass card is purely sensitive to the surrounding magnetic field when the compass is on. If the compass is turned off, then behavior is totally different, more as you describe. I agree that the bearing arrow points in many different directions when you are close to the cache, but the compass card does not shift more than a few degrees at most. In summary, the Vista HCx displays a screen with a bearing arrow overlying a compass card when navigating to a cache. The arrow moves entirely independent of the compass card. The card behaves like any ordinary magnetic compass. It points north, period (when turned on).

Alright, so I worded it badly, but we are on the same page and this is what twolpert was referencing. It does give the perception the compass is bouncing around. Some of you think too much like an engineer and fail to see the perception of an end user.

[+julianh]

Alright, so I worded it badly, but we are on the same page and this is what twolpert was referencing. It does give the perception the compass is bouncing around. Some of you think too much like an engineer and fail to see the perception of an end user.

Maybe that's becasue I AM an engineer!

 

Anyway, no offence was intended, and I hope none has been taken.

 

TotemLake, while I was quoting your message, I sensed that you had the distinction clear, but I thought I would spell out the distinction for the benefit of anyone who might still be confused - the whole issue of whether a compass is necessary / useful, distinction between compass vs. course pointer vs. bearing pointer, red pointer 'bounce', etc, seems to come up very frequently. Maybe what is really needed is for Garmin to rewrite the relevant sections of the user's guides so that typical users can quickly grasp the difference.

Edited March 10, 2009 by julianh

[roybassist]

Re compass and bettery drain: I haven't had my 60CSx for long enough to say for sure, but I know that the effect on battery life was dramatic when I was using the Geko 301.

Garmin has improved the technology used for the compass in their newer models. They draw much less power than the earlier electronic compasses.

 

Annoyedone in the 76C(S)x Yahoo group is an electrical engineer who designs electronic devices for a living. He made measurements of current draw with and without the electronic compass. Here is what he reported for the 76CSx. The numbers are one-minute averages.

 

GPS off, compass off: 36 mA

GPS off, compass on: 37 mA

 

These results are very different from the older 76CS:

 

GPS off, compass off: 67 mA

GPS off, compass on:107 mA

[FanMan]

Garmin has improved the technology used for...He made measurements of current draw...

Interesting, that's good to know. Thanks.

[guggie]

 

Maybe that's becasue I AM an engineer!

Maybe what is really needed is for Garmin to rewrite the relevant sections of the user's guides so that typical users can quickly grasp the difference.

 

And I am an internist, essentially a trouble shooting engineer for human beings. Your comments are "right on course".

 

As a side line, I've noted that the bearing pointer bounces very little if I am near the sought after waypoint or cache, as opposed to the course pointer, which clearly bounces around more, often up to 180 degrees. Both are fine when you are still some distance from the final destination. Try it out on your own. Switch back and forth between the 2 pointers when you are tracking to a cache and see what happens as you get real close.

[+twolpert]

Is it necessary? No. Is it nice to have? Does depend on whom you ask. Some people swear by them -- and some swear at them. The advantage is that the pointer is updated even when you are standing still. And it's updated based on the direction you are facing. The down side is that the pointer may (depending on the unit and local reception conditions) swing wildly when you are near the cache. If that happens, it's worse than not having the compass -- but you can always disable it temporarily.

 

As one other poster said, the arrow you are talking about is NOT the compass arrow. You are talking about a course pointer that is dependent on the GPS signal. There is no way that an electronic compass arrow can "vary widely" when you are near the cache unless the cache area has a magnetic anomaly nearby it.

Edited to add: I think we're all agreed.

 

That's why I said pointer (as distinct from compass heading), by which we all (I hope) mean the thing that tells you which way to go to reach the next waypoint. The pointer incorporates knowledge of your current reported location, the location of the next waypoint, and your direction of travel. If the compass is disabled, direction of travel is based entirely on satellite data. With regard to direction of travel, most units seem to do a good job of smoothing out the quick shifts in reported position which go along with multi-path reception in challenging conditions -- so they tend not to affect the pointer when the compass is off. When the compass is on (and you are standing still or moving slowly), direction of travel (or the direction you are facing) is based on the compass, not satellite information. For whatever reason, most units (my Colorado in particular) seem to do a lousy job of smoothing out multi-path shifts in position as they interact with the pointer in this situation. Hence the wild swings in the pointer. If you disable the compass, the swings largely subside -- not because your reported position is any more stable, but because the unit seems to do a better job of ignoring quick changes in posiition when determining direction of travel.

 

Edited to add: I will say that my PN-40 exhibits a lot less pointer swing than my CO in the same situation. So it does vary by unit. Have to admit that I have forgotten what unit we were originally discussing -- if we ever knew

Edited March 10, 2009 by twolpert

[+TotemLake]

Alright, so I worded it badly, but we are on the same page and this is what twolpert was referencing. It does give the perception the compass is bouncing around. Some of you think too much like an engineer and fail to see the perception of an end user.

Maybe that's becasue I AM an engineer!

 

Anyway, no offence was intended, and I hope none has been taken.

 

TotemLake, while I was quoting your message, I sensed that you had the distinction clear, but I thought I would spell out the distinction for the benefit of anyone who might still be confused - the whole issue of whether a compass is necessary / useful, distinction between compass vs. course pointer vs. bearing pointer, red pointer 'bounce', etc, seems to come up very frequently. Maybe what is really needed is for Garmin to rewrite the relevant sections of the user's guides so that typical users can quickly grasp the difference.

Well ok, that makes sense. And No offence taken.

 

And the distincton is worth noting.

 

guggie

 

As a side line, I've noted that the bearing pointer bounces very little if I am near the sought after waypoint or cache, as opposed to the course pointer, which clearly bounces around more, often up to 180 degrees. Both are fine when you are still some distance from the final destination. Try it out on your own. Switch back and forth between the 2 pointers when you are tracking to a cache and see what happens as you get real close.

 

This is probably true for newer receivers with the capability of locking onto more than 12 birds and has locked onto more than 12 birds.

 

I have noted with the MeriPlat (12 channels) that it has a lot of variance on the bearing when the compass is locked onto the waypoint as a GOTO.

 

On the PN-40, the variance is lessened but I also noted I have more birds locked. If I were to find myself in a situation where let's say less than 12 birds were locked on, I would probably see a greater variance.

 

The only reason I didn't see any variance would be a total signal loss. Then, I wouldn't gain a directional update either as I walk towards and past the target. That happened once. I had to sit at a bench for 20 minutes and regain the signal so I could get close. That was with the MeriPlat.

 

(daggum little laptop screens make editing difficult)

Edited March 10, 2009 by TotemLake

[+Team CowboyPapa]

Regardimg the original question, non-esotoric as it may be:

 

I started geocaching with the DeLorme PN-20 which has no electronic compass and did not miss having one. I don't feel that I left any caches unfound due to not having that capability.

 

I now use the DeLorme PN-40 to which that capability has been added. However, not having been my habit to use it previously, I don't even think about it.

[+dakboy]

I started geocaching with the DeLorme PN-20 which has no electronic compass and did not miss having one. I don't feel that I left any caches unfound due to not having that capability.

Same here. I did, however, keep a cheap Silva orienteering compass with me on many cache hunts, and used that with great success.

 

I now use the DeLorme PN-40 to which that capability has been added. However, not having been my habit to use it previously, I don't even think about it.

I haven't taken my Silva with me since getting my PN-40, but if I do, it'll only be to free up an info field on the PN-40 screens for other data - a need I haven't had yet.

[John E Cache]

That's why I said pointer (as distinct from compass heading), by which we all (I hope) mean the thing that tells you which way to go to reach the next waypoint. The pointer incorporates knowledge of your current reported location, the location of the next waypoint, and your direction of travel. If the compass is disabled, direction of travel is based entirely on satellite data. With regard to direction of travel, most units seem to do a good job of smoothing out the quick shifts in reported position which go along with multi-path reception in challenging conditions -- so they tend not to affect the pointer when the compass is off. When the compass is on (and you are standing still or moving slowly), direction of travel (or the direction you are facing) is based on the compass, not satellite information. For whatever reason, most units (my Colorado in particular) seem to do a lousy job of smoothing out multi-path shifts in position as they interact with the pointer in this situation. Hence the wild swings in the pointer. If you disable the compass, the swings largely subside -- not because your reported position is any more stable, but because the unit seems to do a better job of ignoring quick changes in posiition when determining direction of travel.

Direction of travel has nothing to do with the magnetic compass. The magnetic compass simply tells which magnetic direction the nose of the GPS is pointed.

 

Do the following experiment: When you are near the cache go to the map page. While "not traveling" watch your position relative to the cache. Your position could be N of the cache and the bearing to the cache is S. Because of position error the next position can be 30 feet away. Since you are close to the cache you could now be on the other side of the cache and the bearing is N. The variance in bearing has nothing to do with travel or where magnetic north is.

Edited March 11, 2009 by John E Cache

[guggie]

Direction of travel has nothing to do with the magnetic compass. The magnetic compass simply tells which magnetic direction the nose of the GPS is pointed.

 

Agreed. On the HCx series, your compass card tells you which direction your GPSr is facing. It doesn't matter if you are 1 mile from the cache or on top of it with lousy GPS coverage. It will always indicate the direction you are facing, just like a Silva compass. It has nothing to do at all with the GPS satellites. I think we all agree that some people mistake the overlying pointer/needle for the compass. That can vary widely under certain conditions, e.g., close to the cache, poor GPS satellite coverage, etc. The compass in the HCx units is like the compass on the dash of your car, or on your boat, on in an airplane. It is a rotating card/disc, not the pointer.

[+twolpert]

Direction of travel has nothing to do with the magnetic compass. The magnetic compass simply tells which magnetic direction the nose of the GPS is pointed.

 

Do the following experiment: When you are near the cache go to the map page. While "not traveling" watch your position relative to the cache. Your position could be N of the cache and the bearing to the cache is S. Because of position error the next position can be 30 feet away. Since you are close to the cache you could now be on the other side of the cache and the bearing is N. The variance in bearing has nothing to do with travel or where magnetic north is.

OK, one more time and then I give up. We do not disagree . The shifts in the pointer are due to the abrupt shifts in reported location which typically occur in multi-path conditions.

 

The point I was trying to make is that -- on some units -- the shifts in the pointer are aggravated by having the compass enabled. You can easily see this on the Colorado (for example) by disabling the compass.

 

There is still some confusion between the bearing to next (which is absolute, and is based only on position) and the pointer (which is relative, and takes into account my current heading, or the direction I am facing at the moment). Everything I've said applies to the pointer, not the current heading or to bearing to next, or to anything else . For example, let's say I am 500 feet from the cache (so that multi-path jumps in reported location are not significant) and that the bearing to next is 0 degrees. If I am facing north, the pointer is straight ahead. If I am facing south, the pointer now points directly behind me. Either way, the bearing to next is still 0 degrees, but the pointer changes to show the direction I should go relative to the direction I am going. Hence the dependence on direction of travel.

 

Hope that clears up any remaining confusion -- if there's anybody still reading, or anybody who actually cares (or cared to begin with).

Edited March 11, 2009 by twolpert

[John E Cache]

There is still some confusion between the bearing to next (which is absolute, and is based only on position) and the pointer (which is relative, and takes into account my current heading, or the direction I am facing at the moment). Everything I've said applies to the pointer, not the current heading or to bearing to next, or to anything else . For example, let's say I am 500 feet from the cache (so that multi-path jumps in reported location are not significant) and that the bearing to next is 0 degrees. If I am facing north, the pointer is straight ahead. If I am facing south, the pointer now points directly behind me. Either way, the bearing to next is still 0 degrees, but the pointer changes to show the direction I should go relative to the direction I am going. Hence the dependence on direction of travel.

 

Hope that clears up any remaining confusion -- if there's anybody still reading, or anybody who actually cares (or cared to begin with).

One small nitpick which you are not getting. After years of using a GPS without a compass and holding the GPS pointed straight away some people think the GPS points the direction of travel or "the direction they are facing", it doesn't unless they always point it that way. When I got my 60csx I was happy I could carry the GPS any way I want and still follow the bearing arrow. If I carry my GPS sideways your argument makes no sense to me.

 

I can not resist posting in "compass" threads. If nothing else I keep my "compass post number" up with Prime Suspect.

[+Davensocal]

Gosh, not that I want to keep dragging this up, but now I am confused too..

 

Here is what I understand: (don't worry, it's a short list :-D)

#1- Almost all GPSr have a "compass display". Looking closely, we see that this display shows your direction of travel relative to the compass points. Key point is that it shows your direction of travel based on information derived from the GPS signals, and requires the user to travel, or be travelling in order to determine your direction of travel.

 

#2- Some GPSr include an "Electronic Compass". This device is capable of detecting the Earth's magnetic field (and others!!), and indicating where magnetic north is. This device can work independant of any satellite signals. This device does not require you to be moving in order to display where magnetic north is. This is useful in determining your orientation.

 

Told you it wouldn't be too long...

 

Now, my question:

If your GPSr has an electronic compass, does it orient the map according to the electronic compass when you are not moving?

 

Example:

I am approaching a cache from the south. If I continue on my current course, I will pass the cache to my right side (east). As I approach the cache, I stop to try and orient myself. The GPSr is indicating that I need to travel due east to reach my target, and the bearing indicator is pointing to my right.

 

If I rotate 90 deg to my right, will the map and/or bearing indicator update to show that I should be travelling straight (east)?

 

In my vast experience of about 6 caches, I find that when I approach and stop, sometimes the GPSr swings wildly with each update, the location is about the same, but the direction of travel is moving all over the place, causing the map and the target to change orientation.

 

Hope that makes sense..

Edited March 11, 2009 by Davensocal

[+TotemLake]

Now, my question:

If your GPSr has an electronic compass, does it orient the map according to the electronic compass when you are not moving?

 

Example:

I am approaching a cache from the south. If I continue on my current course, I will pass the cache to my right side (east). As I approach the cache, I stop to try and orient myself. The GPSr is indicating that I need to travel due east to reach my target, and the bearing indicator is pointing to my right.

 

If I rotate 90 deg to my right, will the map and/or bearing indicator update to show that I should be travelling straight (east)?

 

In my vast experience of about 6 caches, I find that when I approach and stop, sometimes the GPSr swings wildly with each update, the location is about the same, but the direction of travel is moving all over the place, causing the map and the target to change orientation.

 

Hope that makes sense..

Older models like the Magellan Meridian and I think the SportsTrak series did not. I can't speak for the newer Magellan series. I understand Garmin does with theirs, and I know the PN-40 does. Couple the imagery with the PN-40, and when the GPS shows your house is on your left, your house is on your left.

[guggie]

 

Now, my question:

If your GPSr has an electronic compass, does it orient the map according to the electronic compass when you are not moving?

 

Example:

I am approaching a cache from the south. If I continue on my current course, I will pass the cache to my right side (east). As I approach the cache, I stop to try and orient myself. The GPSr is indicating that I need to travel due east to reach my target, and the bearing indicator is pointing to my right.

 

If I rotate 90 deg to my right, will the map and/or bearing indicator update to show that I should be travelling straight (east)?

 

My Vista HCx, when set to a bearing indicator, will re-orient the arrow to straight ahead in your example. As far as I can recall, the map screen won't properly re-orient though and will jump around at random at times.

[John E Cache]

Now, my question:

If your GPSr has an electronic compass, does it orient the map according to the electronic compass when you are not moving?

If I put a paper map on the ground with map N pointing N and then put my 60csx on the map, the 60csx map will line up with the paper map. If I rotate the 60csx the 60csx will adjust. If I place my GPS on my location on the map the bearing pointer will point to the destination on the map no mater which way I orient the GPS. The bearing pointer will adjust, also.The point that bugs me the most is that this adjustment is called flopping around by people who have not yet figured out what the electronic compass does. If you are thinking "direction of travel" and pointing the GPS that way, you are thinking way too much. The electronic compass simplifies tings a lot.

[+Prime Suspect]

Gosh, not that I want to keep dragging this up, but now I am confused too..

 

Here is what I understand: (don't worry, it's a short list :-D)

#1- Almost all GPSr have a "compass display". Looking closely, we see that this display shows your direction of travel relative to the compass points. Key point is that it shows your direction of travel based on information derived from the GPS signals, and requires the user to travel, or be travelling in order to determine your direction of travel.

Almost. There is one other key point - when a non-EC unit positions the compass ring, it can only do so by making the assumption that you are pointing the unit in your direction of travel. Hold the GPS just 15 degrees off the direction of travel, and the compass will be 15 degrees off.

 

Now, my question:

If your GPSr has an electronic compass, does it orient the map according to the electronic compass when you are not moving?

Garmins allow you to select if you want the maps to always display north up, or to orient themselves to the real world using the compass reading.

[+julianh]

I can not resist posting in "compass" threads. If nothing else I keep my "compass post number" up with Prime Suspect.

But I'll bet your "compass post number" isn't as high as my "barometric altimeter number"!

[+julianh]

Now, my question:

If your GPSr has an electronic compass, does it orient the map according to the electronic compass when you are not moving?

 

Example:

I am approaching a cache from the south. If I continue on my current course, I will pass the cache to my right side (east). As I approach the cache, I stop to try and orient myself. The GPSr is indicating that I need to travel due east to reach my target, and the bearing indicator is pointing to my right.

 

If I rotate 90 deg to my right, will the map and/or bearing indicator update to show that I should be travelling straight (east)?

On my Summit HC, it is user-selectable. You can orient maps "Track Up" or "North Up".

 

I prefer "North Up", because I have no problem with the mental process of working out which way is left or right, regardless of whether I am navigating north, south, east or west (i.e. up, down, right or left on the map). The map stays "fixed" in the display regardless of how you turn around (just like a paper map, which is what I prefer), your position indicator arrow will spin around as you turn around, and the position indicator stays in the middle of the map screen.

 

Some users prefer "Track Up". In this mode, the map shows a north arrow (which rotates as you rotate), and the map also spins as you change direction, but your position indicator arrow always points up the screen. The position indicator is also moved towards the bottom of the map screen, displaying more of the map "ahead" than "behind" you. I find the refresh time of the map as it rotates can lag a bit if you are changing direction rapidly (especially on detailed topo maps etc), but it works fine if you stay facing in roughly the one direction. When stationary or at very low speeds (with the compass active, calibrated, and the unit held level), the map orientation changes in real-time to reflect the direction you are facing. When moving above the user-selectable threshold speed, it uses the GPS to determine your direction of travel, rather than the electronic compass, and you direction of travel will be up the screen.

 

Hope this helps!