Coordinates

Recommended Posts

As a fairly new person to the hobby I am quickly noticing that many cache owners give lets say iffy coordinates to their caches. Now looking for a micro among ten bushes with good coordinates can be frustrating, when the coordinates are 15 feet off it can increase the difficulty exponentially. Do you think this is done intentionally in order to increase the difficulty level? I enjoy difficult caches, but not when the difficulty is only a result of iffy coordinates.

As a fairly new person to the hobby I am quickly noticing that many cache owners give lets say iffy coordinates to their caches. Now looking for a micro among ten bushes with good coordinates can be frustrating, when the coordinates are 15 feet off it can increase the difficulty exponentially. Do you think this is done intentionally in order to increase the difficulty level? I enjoy difficult caches, but not when the difficulty is only a result of iffy coordinates.

Well sounds like 15 feet isn't that bad...Close enough.... if it was 35 or 40 feet then you might have a complant.

As a fairly new person to the hobby I am quickly noticing that many cache owners give lets say iffy coordinates to their caches. Now looking for a micro among ten bushes with good coordinates can be frustrating, when the coordinates are 15 feet off it can increase the difficulty exponentially. Do you think this is done intentionally in order to increase the difficulty level? I enjoy difficult caches, but not when the difficulty is only a result of iffy coordinates.

Well sounds like 15 feet isn't that bad...Close enough.... if it was 35 or 40 feet then you might have a complant.

I could hide a micro 15 feet off that you could never find, but I always give the correct coordinates.

Not every GPS reads the same, for example a Garmin and a Magellen will read slightly different coordinates at the same spot. Also there is an accuracy error depending on reception for each unit. So if one unit has 8' error and other unit has 12' error you start getting into 20' error range.....possibly.

Not every GPS reads the same, for example a Garmin and a Magellen will read slightly different coordinates at the same spot. Also there is an accuracy error depending on reception for each unit. So if one unit has 8' error and other unit has 12' error you start getting into 20' error range.....possibly.

But if all the other posters are finding the cache 15ft south of the given coordinates, what do you think is going on? If the coordinates given are incorrect 15ft and my gps can have a 15ft error range now we have a 30 foot area to search. Im just encouraging people to give good coordinates and use creativity and inginuity to hide the cache, thats all.

Coordinates can also vary on the day the cache was placed, how many satellites above you at the time, how much cloud cover, the age of the GPS in use for acquiring the coordinates, high sensitivity receiver vs one that doesn't have one, how often the site was averaged, etc...

As you can see, there are many things that can throw off the coordinates. I believe most people try to give accurate ones and if you are having problems, that is what the hint is for.

edited for spelling

Edited by ao318

Coordinates can also vary on the day the cache was placed, how many satellites above you at the time, how much cloud cover, the age of the GPS in use for acquiring the coordinates, high sensitivity receiver vs one that doesn't have one, how often the site was averaged, etc...

As you can see, there are many things that can throw off the coordinates. I believe most people try to give accurate ones and if you are having problems, that is what the hint is for.

edited for spelling

I think most people do give good coordinates, thats not the ones I am talking about. I am not talking about hints, just good coordinates.

Coordinates can also vary on the day the cache was placed, how many satellites above you at the time, how much cloud cover, the age of the GPS in use for acquiring the coordinates, high sensitivity receiver vs one that doesn't have one, how often the site was averaged, etc...

As you can see, there are many things that can throw off the coordinates. I believe most people try to give accurate ones and if you are having problems, that is what the hint is for.

edited for spelling

I think most people do give good coordinates, thats not the ones I am talking about. I am not talking about hints, just good coordinates.

The real question is why are they hidding a Micro in a place that sounds like a Ammo can would be the best choice.

Coordinates can also vary on the day the cache was placed, how many satellites above you at the time, how much cloud cover, the age of the GPS in use for acquiring the coordinates, high sensitivity receiver vs one that doesn't have one, how often the site was averaged, etc...

As you can see, there are many things that can throw off the coordinates. I believe most people try to give accurate ones and if you are having problems, that is what the hint is for.

edited for spelling

I think most people do give good coordinates, thats not the ones I am talking about. I am not talking about hints, just good coordinates.

The real question is why are they hidding a Micro in a place that sounds like a Ammo can would be the best choice.

I agree, and we have one guy in the area that states in his description, the coordinates are only to get you close, you have to use your geosense after that. I have no problem with this because I know I have an expanded search area to contend with, the dudes caches are fun.

As a fairly new person to the hobby I am quickly noticing that many cache owners give lets say iffy coordinates to their caches. Now looking for a micro among ten bushes with good coordinates can be frustrating, when the coordinates are 15 feet off it can increase the difficulty exponentially. Do you think this is done intentionally in order to increase the difficulty level? I enjoy difficult caches, but not when the difficulty is only a result of iffy coordinates.

With only two caches hidden, I would say you have been very lucky if your coordinates are spot on. I would venture to say that the more caches you hide the more likely your coordinates are going to 'seem' a bit 'iffy' to those looking for your cache(s). As has been previously stated, there are any number of factors that can account for the coordinates being 15' off; not the least among them being someone moving the cache to a location that was more in keeping with where they thought the coordinates should have led them. Even with multiple readings and taking an average does not guarantee your coordinates will be exact for everyone else. How close you are to obstructions; i.e. buildings, trees, canyons, etc. can affect your accuracy; both in hiding and seeking a cache. How close you are to a body of water and heavy overcast days will also affect the accuracy. I'm happy if I can find a cache within 15 feet of where the coordinates have led me; such is not always the case.

As a fairly new person to the hobby I am quickly noticing that many cache owners give lets say iffy coordinates to their caches. Now looking for a micro among ten bushes with good coordinates can be frustrating, when the coordinates are 15 feet off it can increase the difficulty exponentially. Do you think this is done intentionally in order to increase the difficulty level? I enjoy difficult caches, but not when the difficulty is only a result of iffy coordinates.

With only two caches hidden, I would say you have been very lucky if your coordinates are spot on. I would venture to say that the more caches you hide the more likely your coordinates are going to 'seem' a bit 'iffy' to those looking for your cache(s). As has been previously stated, there are any number of factors that can account for the coordinates being 15' off; not the least among them being someone moving the cache to a location that was more in keeping with where they thought the coordinates should have led them. Even with multiple readings and taking an average does not guarantee your coordinates will be exact for everyone else. How close you are to obstructions; i.e. buildings, trees, canyons, etc. can affect your accuracy; both in hiding and seeking a cache. How close you are to a body of water and heavy overcast days will also affect the accuracy. I'm happy if I can find a cache within 15 feet of where the coordinates have led me; such is not always the case.

If I hide 100 caches the coordinates will always be spot on, I will double and triple check them if need be. If you know I have only two caches hidden you can read them as well and they are replete with people stating "the coordinates were exact" "I doubted the coordinates but they were spot on" etc. etc. Are you saying that no one "fudges" the coordinates to make a find more difficult?? If so you are a bit naive, these are the ones I am talking about. I am just trying to keep it real.

When placing a traditional geocache, the coords should be as accurate as humanly possible. Intentionally fudging coords to make the cache harder is a sleazy way to cache.

However, 15 ft. is not that far off and I wouldn't automatically chalk that up to being intentional. 15 ft. off is within the error window. 20 ft. off is irritating and should be adjusted. Over 25 feet and the coords definitely need to be updated.

Also, if people want to fudge coords to make the cache harder they should just make it a mystery cache. On the cache page write that the given coords take you to a row of bushes and the cache is hidden somewhere in the row of bushes.

If I hide 100 caches the coordinates will always be spot on, I will double and triple check them if need be. If you know I have only two caches hidden you can read them as well and they are replete with people stating "the coordinates were exact" "I doubted the coordinates but they were spot on" etc. etc. Are you saying that no one "fudges" the coordinates to make a find more difficult?? If so you are a bit naive, these are the ones I am talking about. I am just trying to keep it real.

Say ease up.... I dont think you were being attacked on you Hides just that you dont have but just two. If you see a pattern with a particular CO then dont look for there hides.

As a fairly new person to the hobby I am quickly noticing that many cache owners give lets say iffy coordinates to their caches. Now looking for a micro among ten bushes with good coordinates can be frustrating, when the coordinates are 15 feet off it can increase the difficulty exponentially. Do you think this is done intentionally in order to increase the difficulty level? I enjoy difficult caches, but not when the difficulty is only a result of iffy coordinates.

15 feet isn't too bad considering those satellites are moving at 17,000 miles per hour!

if a certain hider is off more than 20ft and its always the same dir, thats their signature and i'll automatically move GZ by their number of feet.

if its a 999999999999999 rocks hide, i'll just place the cache on ignore.

You simply just can't always get good coordinates.

I recently hid a cache out in the woods and I took five sets of coordinates and averaged them because, in this case, I knew tree-cover would be an issue in collecting the coordinates.

In that method, I took 5 sets of coordinates, and only 2 of those 5 samples were identical to each other.

Though I've found, especially in areas with thick tree cover, it is not unrealistic to be 20-30 feet off. I usually don't get frustrated unless the coordinates are more than 50 ft off, but will mention it in a log if I'm over 30 ft off.

In fact, most GPSr units can tell you how accurate it is, e.g. +/- 12ft. When you see this, you know that once you get to GZ that's the radius you've got to look in.

That and this isn't all supposed to be super easy, the hunt is part of the fun, and the hunt is often just beginning when you get to GZ!

Furthermore, there's nothing wrong with listing in your log that you found it way off and here are some coordinates that may work better. There was one cache in Ohio I did that someone did this and the previous finder's "better" coords too me right to the cache, where was the CO's original coordinates had me about 45 feet off.

many cache owners give lets say iffy coordinates to their cache

First of all welcome to the hobby. When I give my beginning class I ask how many people think that they can follow their GPS to the site, look down and find the cache. More than half think that.

Fifteen feet is well within the acceptable radius. Next time you get a cache in addition to seeing how far off you are look at the EPE which generally means that their is a greater than 50% chance the location (and yours or course) are in that radius. In theory if it is off for both you and the cache in opposite directions you could be that far from it and the coordinate info is correct. Always search at least 2 times EPE

Lastly I disagree with the comment about iffy coordinates. I don't know a single cacher who does that.

Edited by Walts Hunting

If I hide 100 caches the coordinates will always be spot on, I will double and triple check them if need be. If you know I have only two caches hidden you can read them as well and they are replete with people stating "the coordinates were exact" "I doubted the coordinates but they were spot on" etc. etc. Are you saying that no one "fudges" the coordinates to make a find more difficult?? If so you are a bit naive, these are the ones I am talking about. I am just trying to keep it real.

I would be interested in what unit you are using and what kind of area you live in. I use a Garmin GPS 60C and a Garmin Oregon 300. It is rare I can get them both to agree exactly on coordinates. As far as being 'a bit naive', there are probably many things I am 'naive' about; but, I'm not so 'naive' as to believe that even with the newer GPSr units coming out that anyone is always going to be 'spot on' in the coordinates they give for every single cache they place. These units are not built to military precsion; that's why most good units have an accuracy function that allows you to determine just how accurate your unit is at any given time. I've had times when I could get the accuracy to be no better than 40 ft and decided to pass on placing a cache in that location for that reason. But, if you have a unit that can 'guarantee' you will always be 'spot on' with your coordinates I would like to get my hands on one of those.

BTW, you should always double, triple or quadruple check your coordinates when hiding a cache.

Edited by Setan Meyacha

If I hide 100 caches the coordinates will always be spot on, I will double and triple check them if need be. If you know I have only two caches hidden you can read them as well and they are replete with people stating "the coordinates were exact" "I doubted the coordinates but they were spot on" etc. etc. Are you saying that no one "fudges" the coordinates to make a find more difficult?? If so you are a bit naive, these are the ones I am talking about. I am just trying to keep it real.

I have had similar luck when hiding caches. Coordinates seem to be pretty good. No complaints from finders. For a couple of our caches that are under dense tree coverage we provide in-depth hints that will help find the cache.

What I don't like are deliberately fuzzy coordinates. If it's a cache in the woods, it's going to mean stomping around a large area for an extended period of time looking for the cache. It gives caching a bad name - some people (muggles, and land managers) think that's exactly what cachers do all the time - stomp and mash vegetation because GPS coords are not accurate. To deliberately make the coords fuzzy is not good environmental stewardship.

I've also noticed new caches where the CO (mostly newbies) use google maps to get their coords or their cell phone GPS device. First finders then log in that they couldn't find the cache, or found it 50 feet away. The first finders also post new, more accurate coordinates - yet the CO doesn't update the cache coordinates. So frustrating.

If I hide 100 caches the coordinates will always be spot on, I will double and triple check them if need be. If you know I have only two caches hidden you can read them as well and they are replete with people stating "the coordinates were exact" "I doubted the coordinates but they were spot on" etc. etc. Are you saying that no one "fudges" the coordinates to make a find more difficult?? If so you are a bit naive, these are the ones I am talking about. I am just trying to keep it real.

I would be interested in what unit you are using and what kind of area you live in. I use a Garmin GPS 60C and a Garmin Oregon 300. It is rare I can get them both to agree exactly on coordinates. As far as being 'a bit naive', there are probably many things I am 'naive' about; but, I'm not so 'naive' as to believe that even with the newer GPSr units coming out that anyone is always going to be 'spot on' in the coordinates they give for every single cache they place. These units are not built to military precsion; that's why most good units have an accuracy function that allows you to determine just how accurate your unit is at any given time. I've had times when I could get the accuracy to be no better than 40 ft and decided to pass on placing a cache in that location for that reason. But, if you have a unit that can 'guarantee' you will always be 'spot on' with your coordinates I would like to get my hands on one of those.

BTW, you should always double, triple or quadruple check your coordinates when hiding a cache.

.

I am new to geocaching but here are my observations so far. Most caches are placed under trees. I don't think that any amount of averaging will compensate for capturing coordinates in areas where there are natural obstructions to the GPS signal. This is how I think the coordinates should be determined. After deciding on a location, get in an area where there is open sky above and your GPS compass reads a pure north or south direction to the cache about 20 feet away. From here record the east/west coordinates. Likewise move away from the cache into an open area in the east or west direction and record the north/south coordinates. Do this several times and on different days and average. You will be very close. When checking, make sure your GPS points to the cache from every open area. It might also help to calibrate your compass immediately before recording coordinates.

When I am looking for a cache, I use my compass to get a line of sight from 20 feet away with an open sky overhead. I try to intersect the projected lines from a couple of directions, but always consider that one set of coordinates could be off, so I'll try an east/west or north/south only, and use the GPS distance to cache.

many cache owners give lets say iffy coordinates to their cache

First of all welcome to the hobby. When I give my beginning class I ask how many people think that they can follow their GPS to the site, look down and find the cache. More than half think that.

Fifteen feet is well within the acceptable radius. Next time you get a cache in addition to seeing how far off you are look at the EPE which generally means that their is a greater than 50% chance the location (and yours or course) are in that radius. In theory if it is off for both you and the cache in opposite directions you could be that far from it and the coordinate info is correct. Always search at least 2 times EPE

Lastly I disagree with the comment about iffy coordinates. I don't know a single cacher who does that.

What I am talking about is wasting a trip to a cache, spending 20 minutes of so looking for it with no success. Reading the comments where someone posted the correct coordinates, returning to the cache and finding it within two minutes of stopping. This has happened to me three or four times recently. Unless you want to preform an exhaustive exegesis on the caches history everytime before attempting a find, this is irritating. With all the vagaries of the GPS taken into account why can a finder of the cache give spot on coordinates and the cache owner cant?

With all the vagaries of the GPS taken into account why can a finder of the cache give spot on coordinates and the cache owner cant?

I personally have never heard of anyone intentionally fudging the coords... but I do have a theory on this: Most GPSr units take a few minutes to average and get the best signal. Some folks don't take this into account and will take the first reading they get when they walk up to the location.

I try my best when I am placing a cache in the woods, or a place with not the best placing conditions to wait a few minutes to get the most accurate reading that I can. I had a doozy of a time with the most recent series I put out. I had a hard time getting coords on some of them with better than 20 foot accuracy, but I noted that on my cache pages, so that folks would be aware. And I also try to give a pretty good hint if I just cannot for whatever reason get accurate enough coords, even with triple checking them.

So that's my guess, some folks place the cache, turn on their GPSr, get the first numbers that come up and don't wait for them to settle quite enough to be accurate. I could be wrong... but it's the best explanation I can think of.

I can't stand it! I have tried to ignore this thread since it first appeared and it's bugging the heck out of me, so here goes ...

All handheld GPS units are different, not only by manufacturer and model but there are minor (sometimes major) differences between the same models. Like cars manufactured on the day before or after Labor Day, some units just don't have the attention in manufacturing that they should, some slip through QAQC because someone on the line had to deal with a skunk at 3 in the morning and aren't at or near 100%.

There are a million and one reasons for bad coordinates on a stash but the primary reason is there are no handheld units under \$1000 that will regularly provide coordinates within 1 meter of accuracy. Most units are good for a 3 meter radius, that's a 19.68 foot diameter.

About a year ago I read a thread here that included an NGS update for a benchmark made by a geochcher. This geocacher insisted that the benchmark be moved because his \$250 handheld GPS did not agree with the coordinates in the NGS datasheet. I don't think his unit could compare to the \$10000 survey grade unit used to establish the point. The surveyors on the benchmark thread had a ball commenting on it.

I find the hunt fun and keep in mind what the capabilities of consumer grade GPSr's is. If it's within 30 feet, it's pretty tight.

AHHHHHHH, I feel much better now ... thanks!

Cheers,

Panda Inc

So that's my guess, some folks place the cache, turn on their GPSr, get the first numbers that come up and don't wait for them to settle quite enough to be accurate. I could be wrong... but it's the best explanation I can think of.

Which leads to the question, why when given better coordinates from finders, does the CO leave the very inaccurate original coords?

I can't stand it! I have tried to ignore this thread since it first appeared and it's bugging the heck out of me, so here goes ...

All handheld GPS units are different, not only by manufacturer and model but there are minor (sometimes major) differences between the same models. Like cars manufactured on the day before or after Labor Day, some units just don't have the attention in manufacturing that they should, some slip through QAQC because someone on the line had to deal with a skunk at 3 in the morning and aren't at or near 100%.

There are a million and one reasons for bad coordinates on a stash but the primary reason is there are no handheld units under \$1000 that will regularly provide coordinates within 1 meter of accuracy. Most units are good for a 3 meter radius, that's a 19.68 foot diameter.

About a year ago I read a thread here that included an NGS update for a benchmark made by a geochcher. This geocacher insisted that the benchmark be moved because his \$250 handheld GPS did not agree with the coordinates in the NGS datasheet. I don't think his unit could compare to the \$10000 survey grade unit used to establish the point. The surveyors on the benchmark thread had a ball commenting on it.

I find the hunt fun and keep in mind what the capabilities of consumer grade GPSr's is. If it's within 30 feet, it's pretty tight.

AHHHHHHH, I feel much better now ... thanks!

Glad you feel better for venting, but if you had done more than just cursory scan of my posts you would find your response is, shall we say, wanting.

Cheers,

Panda Inc

So that's my guess, some folks place the cache, turn on their GPSr, get the first numbers that come up and don't wait for them to settle quite enough to be accurate. I could be wrong... but it's the best explanation I can think of.

Which leads to the question, why when given better coordinates from finders, does the CO leave the very inaccurate original coords?

Pride.

So that's my guess, some folks place the cache, turn on their GPSr, get the first numbers that come up and don't wait for them to settle quite enough to be accurate. I could be wrong... but it's the best explanation I can think of.

Which leads to the question, why when given better coordinates from finders, does the CO leave the very inaccurate original coords?

Pride.
Charlie?

If I hide 100 caches the coordinates will always be spot on, I will double and triple check them if need be. If you know I have only two caches hidden you can read them as well and they are replete with people stating "the coordinates were exact" "I doubted the coordinates but they were spot on" etc. etc. Are you saying that no one "fudges" the coordinates to make a find more difficult?? If so you are a bit naive, these are the ones I am talking about. I am just trying to keep it real.

I didn't get past this. Double and triple check them if need be? That's it?

I set my unit to auto average every 3 seconds and walk away from it for 15 to 20 minutes. That is 300 to 400 samples. I always get a minimum 5 foot deviation on that set and when I came back to take readings on another day I can never get Marked GZ to line up with True GZ, I'm always off by at least 3 feet.

How many pounds are you lugging that you only double or triple check your coords if need be?

My search radii is 50' when caching, because I know how off the units can be and the minuscule fuzzy you're talking is not big enough for me to accuse somebody of doing it on purpose.

I'll let you in on something, there are more than a few who will lie to a hider about their coords to encourage them to hide more. A slightly off cache is better than no cache at all, unless it is a nauseum cache.

Now looking for a micro among ten bushes with good coordinates can be frustrating, when the coordinates are 15 feet off it can increase the difficulty exponentially.

No handheld portable GPS receiver is capable of consistently reporting a location within 15 feet of accuracy. When you get within 25 feet or so of Ground Zero, it's time to put away the GPSr and use your GeoSense to search for the cache.

If the hider used a \$10,000 professional surveyor's system to determine the coordinates down to the centimeter, your GPS receiver would still make you think the coordinates were 10 to 15 feet off. It's just the nature of the system, they were never intended to do any better than that.

So that's my guess, some folks place the cache, turn on their GPSr, get the first numbers that come up and don't wait for them to settle quite enough to be accurate. I could be wrong... but it's the best explanation I can think of.

Which leads to the question, why when given better coordinates from finders, does the CO leave the very inaccurate original coords?

That is a good question. I have wondered that myself on numerous occasions. Laziness??

That is a good question. I have wondered that myself on numerous occasions. Laziness??

how does the CO know that the given coords are better than their own?

yeah i know it's obvious from the comments myself, but i guess that may be a reason why a CO won't update the coords

I currently have 22 published cache pages. On four of these, I have been told a few times that the coordinates are way off. However, when I go to check, my GPSr hits zero within 3 feet of the cache.

I ran into a fellow cacher once while out for cache maintenance on one of these caches. Now, he has a similar GPSr to the one I have (same brand, different model) and after he made the find, we compared numbers. Both of our GPSr units were showing zero at the same spot... within arm's reach of the cache.

Do I have a top of the line GPSr? Nope.

Is it possible that other GPSr units read differently than mine? Sure, it is.

Will I be changing the coordinates of these caches? Not as long as my GPSr takes me directly to ground zero.

That is a good question. I have wondered that myself on numerous occasions. Laziness??

how does the CO know that the given coords are better than their own?

yeah i know it's obvious from the comments myself, but i guess that may be a reason why a CO won't update the coords

That is a REALLY good point. How would they know? The person giving "better" coords could be completely off.

As with many aspects of geocaching, this comes down to knowing your instrument. Any rule-of-thumb radius is useless; it depends very much on the local environment. In an area with a good view of most satellites, I would expect 10 feet or less. In the woods with heavy tree cover, 30 feet is probably more usual. I have found a couple in deep canyons that read 60 feet off in my unit, but I didn't peep about the coords because that seemed reasonable.

So here is my advice to newbies: Learn how your GPS works and how it behaves in a variety of situations. If you don't understand how your GPS works and what effects can cause coordinate errors, don't complain about other peoples' coordinates.

Is it possible that other GPSr units read differently than mine? Sure, it is.

yeah but they shouldn't differ significantly.

when someone else is getting coords "way off" while you're certain that they are not, chances are the reason for this is a different datum, such as WGS84 vs NAD27.

I cached for a while with a 7 year old Garmin. It generally was 100 feet off. made caching very challenging.

Check the date on the cache. If it's an old cache and the coords have not been updated, the coord's were gotten with a machine with inferior technology. No WAAS. Try that out sometime. YUCK!!

there are more recent inferior models on the market.

I know someone who was hiding their caches and getting coords with a new I-phone. The coords were generally 100 feet off.

There are many other variables too as others have mentioned.

If you consistently get one hider's coord's as being off, that probably means they have inferior equipment, and not that they intend to decieve.

Edited by Sol seaker
That is a good question. I have wondered that myself on numerous occasions. Laziness??

how does the CO know that the given coords are better than their own?

yeah i know it's obvious from the comments myself, but i guess that may be a reason why a CO won't update the coords

That is a REALLY good point. How would they know? The person giving "better" coords could be completely off.

Usually one finder posts his coordinates. Then the next person said, the posted coordinates put me 2 feet into the river, used Electrocutie's coordinates, they were spot on. Then the next person logs a similar message. Then another person logs how they found it with Electrocutie's coords. I think that tells you something.

Edited by Lone R
Is it possible that other GPSr units read differently than mine? Sure, it is.

yeah but they shouldn't differ significantly.

when someone else is getting coords "way off" while you're certain that they are not, chances are the reason for this is a different datum, such as WGS84 vs NAD27.

Well put! I don't recall anyone actually putting a number on their "way off" diagnosis, so it might not actually be that far off.

Like I said before, as long as my GPSr takes me directly go GZ, the coordinates will stand.

Is it possible that other GPSr units read differently than mine? Sure, it is.

yeah but they shouldn't differ significantly.

when someone else is getting coords "way off" while you're certain that they are not, chances are the reason for this is a different datum, such as WGS84 vs NAD27.

Well put! I don't recall anyone actually putting a number on their "way off" diagnosis, so it might not actually be that far off.

Like I said before, as long as my GPSr takes me directly go GZ, the coordinates will stand.

There is about a 200m difference, depending on the datum. The two main datums in Canada are WGS84 and NAD27. "NAD27" means "North American Datum 1927". "WGS 84" means "World Geodetic System 1984". Eventually all maps will be WGS84, because it is based on satelite measurements. However, most Canadian topographic maps are still NAD27. The difference can be as much as 200 meters, depending on your location.

So if your using NAD27 to get your coords, you would leave the coords as is even though everyone else is using WGS84? Would you at least post in your clues that you are using NAD27 coords?

Is it possible that other GPSr units read differently than mine? Sure, it is.

yeah but they shouldn't differ significantly.

when someone else is getting coords "way off" while you're certain that they are not, chances are the reason for this is a different datum, such as WGS84 vs NAD27.

Well put! I don't recall anyone actually putting a number on their "way off" diagnosis, so it might not actually be that far off.

Like I said before, as long as my GPSr takes me directly go GZ, the coordinates will stand.

There is about a 200m difference, depending on the datum. The two main datums in Canada are WGS84 and NAD27. "NAD27" means "North American Datum 1927". "WGS 84" means "World Geodetic System 1984". Eventually all maps will be WGS84, because it is based on satelite measurements. However, most Canadian topographic maps are still NAD27. The difference can be as much as 200 meters, depending on your location.

So if your using NAD27 to get your coords, you would leave the coords as is even though everyone else is using WGS84? Would you at least post in your clues that you are using NAD27 coords?

That's a non-issue. I'm using WGS84. Plus, I'm in the US. Do you post in your clues that you use WGS84?

*Edited to say that the link doesn't work on my end.*

Edited by SandyCreekPirates
Is it possible that other GPSr units read differently than mine? Sure, it is.

yeah but they shouldn't differ significantly.

when someone else is getting coords "way off" while you're certain that they are not, chances are the reason for this is a different datum, such as WGS84 vs NAD27.

Why should they not? Different OEM is different OEM.

Some units run on Windows some on Linux.

Some units update at 5 times a second most update between 1 and 5 seconds and I have heard of units that take 10.

Some units use projected figures to appear to update faster based on past calculations and can not accurately calculate until you have let it rest long enough to purge its backmem of movement readings.

Some receivers will not display updated coords if you have not moved far enough since the last reading.

WASS is going to be different than non. The best difference I have seen in my own unit is 9' and the worst I can remember is.. well I cant remember but it was in the upper 30s and it put me 5' from true GZ when I turned it off.

Internal antenna vs external antenna vs Joe Blow who thinks he can build an antenna.

Internal or external power supply, and how close the external is to the unit. Even the composition of batteries can effect accuracy, causing two of the same models to show different readings. Some insignificant, some not so insignificant.

Add in the fact that different companies believe their math is better for handling error sources like geometric dilution, atmospheric, and multipath effects.

You have eTrex and GPSMap users (I'm betting even more models) that don't even know they need to do a system reset every so often. My brother has to reset about once a month because he gets skewed by about 60' roughly SE.

Lots and lots of reasons why receivers can be dramatically different. In a perfect world they shouldn't be but the fact remains that they can be.

Back to OP, and non of them intend to deceive.

Fifteen feet inaccuracy is not worth posting about.

Is it possible that other GPSr units read differently than mine? Sure, it is.

yeah but they shouldn't differ significantly.

when someone else is getting coords "way off" while you're certain that they are not, chances are the reason for this is a different datum, such as WGS84 vs NAD27.

Well put! I don't recall anyone actually putting a number on their "way off" diagnosis, so it might not actually be that far off.

Like I said before, as long as my GPSr takes me directly go GZ, the coordinates will stand.

There is about a 200m difference, depending on the datum. The two main datums in Canada are WGS84 and NAD27. "NAD27" means "North American Datum 1927". "WGS 84" means "World Geodetic System 1984". Eventually all maps will be WGS84, because it is based on satelite measurements. However, most Canadian topographic maps are still NAD27. The difference can be as much as 200 meters, depending on your location.

So if your using NAD27 to get your coords, you would leave the coords as is even though everyone else is using WGS84? Would you at least post in your clues that you are using NAD27 coords?

That's a non-issue. I'm using WGS84. Plus, I'm in the US. Do you post in your clues that you use WGS84?

*Edited to say that the link doesn't work on my end.*

Sorry, misunderstanding....I thought you said you were using NAD27.

Not every GPS reads the same, for example a Garmin and a Magellen will read slightly different coordinates at the same spot. Also there is an accuracy error depending on reception for each unit. So if one unit has 8' error and other unit has 12' error you start getting into 20' error range.....possibly.

You don't have to compare a garmin to a magellen to get slightly different co-ordinates, the same GPS of any brand will do that. Just look at your location while standing still and it will move all over the place. It is this inaccuracy that is the basis of the game. If it were - "Dead On Balls Accurate" you could reach down and pick it up. If you average 100 times 3 times in a row - your average will vary as well. So don't be too worried - get close and put it down - start playing the game.

Here we go - it is around her somewhere. We don't know where it is - so LOOK for it! Now we are having fun!

Edited by GPS-Hermit

15 feet is pretty good, today I was finding most 35-50 feet away

Here's an experiment.

Put a wooden stake in the ground. Set your GPSr on top of the stake. Wait for it to settle. If you would like, set it to average readings over five minutes or more. Mark the waypoint.

Now take your GPSr with you, and go do something else for a half hour. Then set your GPSr to navigate to the waypoint you previously set, go back to your wooden stake, set the GPSr on top of it. See how far away it says the waypoint is.

The distance will vary, but I'd be willing to bet it is not "0 feet."

Different satellites overhead, in different positions, are going to give slightly different coordinates. This is inherent in the system and is no reflection of the quality of your GPS or your ability to use it.

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

×   Pasted as rich text.   Paste as plain text instead

Only 75 emoji are allowed.