Coords starting or actual location?

[mddbkzr]

I am new to the GC community and have a question... I have searched for at least 10 different caches, and I have not found one yet (all small and micro caches as the larger boxed ones are a bit farther from home).

A few questions:

 

Are the coordinates given the "entry" to the woods/water/path/whatever or the actual location itself of the cache? Very few if any actually state "coords are starting point" or anything like that, yet some say "a short walk into the woods" as if it was a starting point without giving any extra info. Several coordinates were located exactly on a sidewalk or parking spot yet says "a short walk into the woods"...

So that means it can be anywhere from 5 to 500 feet from that location? When there is several acres of woods and it is a micro, short of bringing a metal detector, there is not enough information to find without specific terminology, tips, or maybe I just happened to pick 7 or 8 of them that were muggled recently???

 

Thanks for the help!!

[+SkellyCA]

The coords on the cache page are the the location of the cache +- 10 or 20 feet. Some caches include extra coords for parking or trail heads and such.

[+kunarion]

Several coordinates were located exactly on a sidewalk or parking spot yet says "a short walk into the woods"

What kind of GPSr do you have? If it's a handheld, be sure to select "WGS84 Datum" (Not NAD27) -- it's a map system setting. For either a car or hiking GPSr, select "pedestrian" or "recreational", or "geocaching" mode. It must not be in "automotive street routing" which will always point to the nearest street.

 

For a "Traditional Cache" (green box icon on the page next to the cache name), the coordinates are at the location of the cache. You can typically expect the cache to be within 40 feet of the coordinates. Often, it's much closer.

 

Read the recent logs. If it's been found recently, and particularly if there's a mention about how accurate the coordinates are, that's a good one to try. Look for hints that will help narrow things down once you arrive.

 

Micros in the woods? Sorry to see that.

Edited March 3, 2010 by kunarion

[+Brooklyn51]

Check the terrain and difficulty ratings of the caches you are looking for. For beginners to the sport, it's probably best to stick with ratings around 1-1.5 for the first few. The higher the number, the harder the find will be- terrain obviously is for how tough the walking will be and difficulty usually relates to how well hidden it is. The coordinates should be fairly close though, within 10-20 feet. Once you get to GZ (ground zero) start looking for likely hiding spots, use your geosenses. Keep at it, it won't be long before you start finding 'em. Good luck!

[+StarBrand]

Why isn't the cache where my GPS says it should be?

 

The general accuracy of most handheld GPS devices is around 15 to 25 feet. Remember though you have might have to add your potential error to any error the cache owner had when placing the cache. That means you could easily find yourself looking for a cache up to 50 feet from where your unit says ground zero is. Most of the time you will find them within 20 feet or less but do be prepared to widen your search. Put the GPS away when you are within 20 feet or so and start looking for likely hiding spots.

 

Back off and re-approach the area if necessary to verify you are looking in the right spot.

 

Tips for finding Caches:

Here are some general hints:

 

Look for caches with a difficulty of 2 or less for your fist few caches. Stick with regular sized caches for your first few. Micros can be quite hard to find sometimes. Stick to areas you are familiar with. Look for anything out of place or unusual. Look for unusual piles of sticks, grass, leaves, rocks, sand, etc. Feel where you cannot look. Think vertical, not all caches are on the ground. Look up or at eye level. Look for traces of previous searches to zero in on the spot. Think like the hider - where would you put a container in this location? Look for things too new, too old, too perfect, not like the others, too many, too few. Change your perspective - a shift in lighting can sometimes reveal a cache. Keep in mind that many micros are magnetic or attached to something (via string, wire etc). Slowly expand your search area to about 40 feet from where your GPS says ground zero is. Bring garden gloves and a flashlight - they help! Be prepared to not find the cache more often then you think.

 

Most of all - have fun!!

[mddbkzr]

Thanks for the information everyone.

I understand the technical aspects. My unit is using the WGS84 datum, and is also equipped with WAAS so it is exact within 3 meters/10 feet and always has very good signal strength with 5+ satellites even in heavily wooded areas. I also understand the people that placed it may have an older/cheaper unit or not as experienced with GPS units, so it may not be as exact. I tend to keep my search within 30 feet and post a DNF if I cannot find it.

 

As I work my way out, I plan to start looking for the larger item/boxed caches when I get the chance, I know of an area within a mile of here that has 3 or 4 within a 1/4 mile area, all boxes.

 

Micros in the woods? Sorry to see that.

yes this seems to be a common theme with many of the nearby caches... Edited March 3, 2010 by screwballl

[+StarBrand]

Thanks for the information everyone.

I understand the technical aspects. My unit is using the WGS84 datum, and is also equipped with WAAS so it is exact within 3 meters/10 feet and always has very good signal strength with 5+ satellites even in heavily wooded areas. I also understand the people that placed it may have an older/cheaper unit or not as experienced with GPS units, so it may not be as exact. I tend to keep my search within 30 feet and post a DNF if I cannot find it.

 

As I work my way out, I plan to start looking for the larger item/boxed caches when I get the chance, I know of an area within a mile of here that has 3 or 4 within a 1/4 mile area, all boxes.

 

Micros in the woods? Sorry to see that.

yes this seems to be a common theme with many of the nearby caches...

Actually the WAAS units have been around for 9 years or more.

 

I rather gaurantee that your unit is NOT "exact within 3 meters" except under the most ideal of circumstances. That figure is a sort of "up to 3meters" not a firm always. The actual error of most modern handheld units is around 15 to 25 feet under "average" conditions.

[7rxc]

I am new to the GC community and have a question... I have searched for at least 10 different caches, and I have not found one yet (all small and micro caches as the larger boxed ones are a bit farther from home).

A few questions:

 

Are the coordinates given the "entry" to the woods/water/path/whatever or the actual location itself of the cache? Very few if any actually state "coords are starting point" or anything like that, yet some say "a short walk into the woods" as if it was a starting point without giving any extra info. Several coordinates were located exactly on a sidewalk or parking spot yet says "a short walk into the woods"...

So that means it can be anywhere from 5 to 500 feet from that location? When there is several acres of woods and it is a micro, short of bringing a metal detector, there is not enough information to find without specific terminology, tips, or maybe I just happened to pick 7 or 8 of them that were muggled recently???

 

Thanks for the help!!

Good descriptions have been given for traditional caches, but watch out for the ? ones... THEY can be starting points or other... HOWEVER, there should be a NOTE stating that the cache is NOT at those coordinates... Just something to consider.

 

Stay with the larger traditionals until you get it figured out... Happy Hunting.

and Welcome.

 

Doug

[+StarBrand]

Thanks for the information everyone.

I understand the technical aspects. My unit is using the WGS84 datum, and is also equipped with WAAS so it is exact within 3 meters/10 feet and always has very good signal strength with 5+ satellites even in heavily wooded areas......

As a followup to my last post - try this experiment.

 

Go out to a spot in your yard. Mark it and record the coordinates.

 

Then over the next week. Go out 4 random times of the day each day and goto those coordinates until your unit is zeroed for the coordinates (not the spot you chose). Put a flag down each time.

 

I'll bet your flags are sporadically spread out over an area around within +/- 25 feet from the original spot in nearly every direction.

[tiiiim]

Thanks for the information everyone.

I understand the technical aspects. My unit is using the WGS84 datum, and is also equipped with WAAS so it is exact within 3 meters/10 feet and always has very good signal strength with 5+ satellites even in heavily wooded areas. I also understand the people that placed it may have an older/cheaper unit or not as experienced with GPS units, so it may not be as exact. I tend to keep my search within 30 feet and post a DNF if I cannot find it.

 

As I work my way out, I plan to start looking for the larger item/boxed caches when I get the chance, I know of an area within a mile of here that has 3 or 4 within a 1/4 mile area, all boxes.

 

Micros in the woods? Sorry to see that.

yes this seems to be a common theme with many of the nearby caches...

Actually the WAAS units have been around for 9 years or more.

 

I rather gaurantee that your unit is NOT "exact within 3 meters" except under the most ideal of circumstances. That figure is a sort of "up to 3meters" not a firm always. The actual error of most modern handheld units is around 15 to 25 feet under "average" conditions.

 

I've always wondered about this. I cache with a netbook and GPS dongle. Very often the screen readout tells me that my horizontal accuracy is +/- 1m. So is that not true? I got it a lot when caching in Canada with 10+ satellites in view including WAAS. But I also seem to get it here in Britain with no WAAS. The vertical error is usually between 2 and 5 metres. Just curious....

 

(For info, the program I use to show me this error is cgps (which uses gpsd to gather data from the dongle). A screenshot of someone else's is shown here http://home.zyrianes.net/blog/static/includes/cgps.png, with their horizontal accuracy at +/- 24 metres

[+StarBrand]

....I've always wondered about this. I cache with a netbook and GPS dongle. Very often the screen readout tells me that my horizontal accuracy is +/- 1m. So is that not true? I got it a lot when caching in Canada with 10+ satellites in view including WAAS. But I also seem to get it here in Britain with no WAAS. The vertical error is usually between 2 and 5 metres. Just curious....

 

(For info, the program I use to show me this error is cgps (which uses gpsd to gather data from the dongle). A screenshot of someone else's is shown here http://home.zyrianes.net/blog/static/includes/cgps.png, with their horizontal accuracy at +/- 24 metres

That figure is generally known as an EPE (Estimated Positional Error). It is derived from a number of factors including signal strength, number of sats and the geometry between them. However in the end - it is just an estimate - a fairly low confidence estimate.You should read it something like "The current reading might be about xxx feet from the actual coordinates under these same conditions about 60% of the time". What the actual error is could be several times the reading or several times less. You just can't know. Then you have to consider the possiblility of multipath errors for the signals and the possibility of signal interference and more.

 

Survey and Military grade equipment can further refine these reading down to about 3cm of accuracy but our cheap handhelds just are not that precise and don't have access to the better signals from the sats.

[mddbkzr]

As the official GPS and WAAS spec states is that with WAAS, accuracy is within 3m (9.9ft) over 95% of the time. It should not matter if it is a cheap handheld or high dollar unit.

With mine, it shows typically 4-5 satellites with very good signal strength plus 5-10 more with low to medium signal strength and so far over the course of the past week or so that I have had it, standing in one spot at the corner of my driveway is always within 1-2 digits to the 5th decimal. Now if I just turn it on and move around and try it then within only a few minutes before it gets a good signal lock then yet it is off, but within 3-4 minutes it has good lock and excellent positioning.

I still understand the possibility for discrepancy (within 25 ft) but I do know being close to a large military area (Eglin Reservation), they keep things working very well with the local WAAS equipment due to all the missions they run on close to 500,000 acres.

I will post a few examples and numbers from my unit when I get a chance, I will use a local fishing hole since it is same place all the time.

 

Again, thanks for the information everyone!

 

 

edit1: The circle in front of my house 30.52349, -86.46632 (only the last decimal digit off from my original reading set a few days ago on my profile)

Edited March 4, 2010 by screwballl

[+kunarion]

I’ve found almost 200 caches, and have never checked what the current accuracy level was. I’ve even hidden 2 caches, and didn’t even check the accuracy level for those when I hid them. One of those is so close to actual GZ, people mention that in the logs.

 

I’ve also found caches that were accidentally placed 200 feet or more from the listed coordinates -- you’ve gotta check the logs to be sure that people are finding it. Some places, the reading swings wildly – such as next to tall buildings or in forests. After a long hike into the woods, you’ll have to go with whatever accuracy you’ve got.

 

So, don’t rely heavily on the GPSr, however accurate it says it is. Once you’re within a reasonable range (say, just under 40 feet), it’s time to think like a hider, and start the search. If I look around and see a better spot 50 feet away, I’ll ignore the GPSr and go check it out. Sometime’s that’s where the cache is.

[mddbkzr]

I finally found my first (close to home, a micro/small in a forested area)... it was about 10 feet away from the exact coordinates which were in an open spot close to the cache, so they probably did not have a clear signal in the woods, but it was still well within the expected area. There was no elevation data so I had no idea if it was on the ground, up a tree, muggled, or blown away into the nearby drainage ditch. I may have to include elevation data if I ever decide to hide one myself.