Branny-spankin' New

[Luvs5rugrats]

Hi! I've been browsing this website for over 2 years, waiting patiently for the opportunity to get into this! Getting a GPS was my issue, but I got a used, older one off of ebay as it fit my price range nicely. It's a Magellan GPS Blazer 12, no bells and whistles, very basic "point a to point b" kind of thing. Second issue: I have five kids, two of them being 14 month old twins. I don't plan on taking the twins but doing this mostly in the evenings after the babies have gone to bed.

 

Now, where do I begin? I've got several easy "kid friendly" park and find style caches in my area, which is just my speed--anything other than that might be too difficult with three kids. My main intimidation is also my GPS device, I have no clue how to use it. I do have the manual and managed to set up my home location. Are there any "GPS for dummies" tips out there for me?

[+briansnat]

Figure out how to enter coordinates in your GPS. THe usual way is to mark them, then edit the coords to match those of the cache. Then hit Go To and follow the arrow. All there is to it.

[Luvs5rugrats]

I guess my main issue is with just that--entering coordinates. I know how to do it but seem stuck on the format. For example, my device is set up in Lat/Lon, DegMin format. For example, say I'm looking at a cache in my hometown with the coordinates N00 12.345 but the format on my device looks like this: N00 12.34, it doesn't give me three spaces after the decimal so I can't enter the coordinates for the cache. What do I need to change to enter them correctly? I guess my question is what format are the coordinates given in the caches?

 

Does that make any sense? Told you I needed a dummies guide to this.

[+WeightMan]

It is not Geocaching for Dummies, but The Complete Idiot's Guide is available.

 

People have cached with two digit units like yours. All you need to do is round the listed coordinates to two places and enter those. Realize that your position error will be rather large. Instead of 20 feet or so, you will be more likely around 200 feet. That will be a rather large search area so get good aerial photos and/or maps the limit the search. Aerial photos (and topos) are available here. All you need to do is enter the GC number of the cache. You can use Lots of Maps or my favorite Terraserver. One of the neat things about this website is that it will plot all waypoints listed on the cache page. That is helpful on multi caches.

[+Team Red Oak]

Hi-

 

I just wanted to say welcome to caching and TWINS never double trouble, always twice the fun! Mine are 17 years old.

 

I know nothing about your brand of GPSr, but you could look at your local area and see if there is anyone you could cache with in order to get a feel for how close your unit comes to the cache.

 

Just scroll down the forum page to the regional sites and find your location. If you happen to be in the Baltimore or DC area let me know.

[+Team Cotati]

When you set up your home location, were you required to enter coordinates?

[Luvs5rugrats]

LOL, no, it used satelite location.

 

It figures I got one that wasn't gonna be as precise as I would have liked. 20 feet I can deal with but 200 feet? Really? I tried looking for as much information as I could as far as what features I would need to do this kind of thing but this was something that I never read about or thought about because GPS devices are very new to me.

 

Oh, well. I'll use this one the best I can until I can afford a newer one.

 

Thanks for your replies!

[+WeightMan]

200 feet it is. You are entering one tenth of the precision of the indicated coordinates so you should expect ten times the error. Don't be discouraged. Some people have found many caches without a GPSr at all. They use every clue they can get, including those I mentioned before. It can be done. In fact, some like the challenge.

[+IVxIV]

Those Blazers are indeed pretty old.. if you want to increase your accuracy a bit, try switching to use the UTM coordinate format instead. It should allow a bit better precision, and not force you to round up/down your lat/long's

 

And make sure your datum is set to WGS84!

[bibsken]

Figure out how to enter coordinates in your GPS. THe usual way is to mark them, then edit the coords to match those of the cache. Then hit Go To and follow the arrow. All there is to it.

What exactly do you mean by "mark them" briansnat ?

Bibsken.

[+blindleader]

200 feet

????????

 

Where does this come from? .01' of latitude is about 60 feet so the precision of the measurement is ±30 ft. Add to that the probable uncertainty in the actual measurement to get a reasonable search area. If the unit allows input of coordinates in UTM format, check to see what percision it accepts and use it if it's better than the decimal minutes format.

[+Skyman]

Figure out how to enter coordinates in your GPS.  THe usual way is to mark them, then edit the coords to match those of the cache.  Then hit Go To and follow the arrow. All there is to it.

What exactly do you mean by "mark them" briansnat ?

Bibsken.

Hi there I'll jump in a little, the term Mark is used as a reference as to (mark your position) or MOB (Man over Board) in most cases it will mark your present position with one push of the button. With this info which should have the Lat & Lon for your position at the time the button was pushed and is saved then you can then edit the info as you wish i.e. with the coordinates of the cache.

Edited July 28, 2005 by Skyman

[+WeightMan]

200 feet

????????

 

Where does this come from? .01' of latitude is about 60 feet so the precision of the measurement is ±30 ft. Add to that the probable uncertainty in the actual measurement to get a reasonable search area. If the unit allows input of coordinates in UTM format, check to see what percision it accepts and use it if it's better than the decimal minutes format.

I based the 200 feet on the precision and the normal EPE. Your analysis is fine as long as there is no error in the measurement itself. Since that is not the case, I will stick with my approx. number. The actual number is probably somewhere between our two numbers.

 

Not having used a GPSr with only two digit precision, I can't say how well the UTM coordinates will work on this model. That may well be the best way to go. In fact, I did have to use UTM for one particular cache, which shall remain nameless to protect the puzzle. What I did though was convert the UTM back to degrees and minutes and use that.

[+Skyman]

Figure out how to enter coordinates in your GPS.  THe usual way is to mark them, then edit the coords to match those of the cache.  Then hit Go To and follow the arrow. All there is to it.

What exactly do you mean by "mark them" briansnat ?

Bibsken.

Hi there I'll jump in a little, the term Mark is used as a reference as to (mark your position) or MOB (Man over Board) in most cases it will mark your present position with one push of the button. With this info which should have the Lat & Lon for your position at the time the button was pushed and is saved then you can then edit the info as you wish i.e. with the coordinates of the cache.

Also referred to as manually entering a waypoint.

[+blindleader]

I based the 200 feet on the precision and the normal EPE.  Your analysis is fine as long as there is no error in the measurement itself.  Since that is not the case, I will stick with my approx. number.  The actual number is probably somewhere between our two numbers.

Pardon my bluntness but this is nonsense. My analysis is complete and correct.

 

To reiterate:

The uncertainty due to precision of the data entry is ±30 ft.

The uncertainty due to inaccuracy of the measurement itself is a different matter and needs to be accounted for in the search, as I stated.

 

This is the key. The uncertainty of the accuracy of the measurement is the same for an old Blazer 12 as it is for any new consumer GPS (not using WAAS). EPE does not depend in any way on the number of digits the unit allows you to enter.

 

Maybe repetition will help:

EPE does not depend in any way on the number of digits the unit allows you to enter.

[+WeightMan]

I based the 200 feet on the precision and the normal EPE.  Your analysis is fine as long as there is no error in the measurement itself.  Since that is not the case, I will stick with my approx. number.  The actual number is probably somewhere between our two numbers.

 

EPE does not depend in any way on the number of digits the unit allows you to enter.

OK, I was wrong.

 

I take it from what you said that the expected error could be as much as 90 feet though. That is still a fairly large area to search.

 

My apologies for not thinking this completely through.

[+BlackstoneVal]

Luvs5rugrats, Before you put the GPSr away, some receivers allow multiple formats for coordinates. When you find the MENU screen for what is usually called SETUP, you may be allowed to change what is sometimes called UNITS. You may be defaulting to (DD MM.MM) degree minutes with 2 decimal places, but there may be an option for (DD MM.MMM) 3 decimal places. If it allows you to switch to UTM, as some have suggested, that should be a bit more precise than even the 3 decimal minute format.

[Luvs5rugrats]

Thanks for all your replies. I was able to use the UTM format and found my first cache today. It was very precise and pointed us in the right spot. We found the cache with little difficulty once we got to the general area.

[+Maingray]

Congratulations on #1!

[+Team Cotati]

I am continually amazed by the number of people who seem to take great pleasure in trying to portray this game as something complicated.

[Difficult Run]

I am continually amazed by the number of people who seem to take great pleasure in trying to portray this game as something complicated. 

For the technical folks out there, programming your GPSr isn't rocket science, but a lot of folks don't have the aptitude for doing what seems easy for the majority of us.

 

So, let's be helpful and not condescending about the newbies, ok??

 

- Mitch -

[+Team Cotati]

I am continually amazed by the number of people who seem to take great pleasure in trying to portray this game as something complicated. 

For the technical folks out there, programming your GPSr isn't rocket science, but a lot of folks don't have the aptitude for doing what seems easy for the majority of us.

 

So, let's be helpful and not condescending about the newbies, ok??

 

- Mitch -

I am continually amazed by the number of people who seem to take great pleasure in trying to portray this game as something complicated. "Luvs5rugrats, Before you put the GPSr away, some receivers allow multiple formats for coordinates. When you find the MENU screen for what is usually called SETUP, you may be allowed to change what is sometimes called UNITS. You may be defaulting to (DD MM.MM) degree minutes with 2 decimal places, but there may be an option for (DD MM.MMM) 3 decimal places. If it allows you to switch to UTM, as some have suggested, that should be a bit more precise than even the 3 decimal minute format. " I'll try and keep that in mind going forward. Thanks for your friendly reminder.

Edited July 30, 2005 by Team Cotati