Go 200 Feet

[+Team Wiggy]

Please bear with me if this is really dumb... but here goes...

 

We've found several multi-caches recently that tell us to go (for example) 200 feet in a given direction to find the final cache.

 

We've figured nothing out on our GPS yet (ETrex Legend) except how to watch the coords change as we get closer to the target. (Who has time to read the book? There are caches to find!)

 

What I'm wondering is... is there a correlation or a formula between the coords and feet? Is there a way to figure out that 200 feet changes the coordinate by x amount of degrees, or do I just need to count off my paces? Surely with all this technology there's a better way than counting as I walk (and more accurate too).

 

Thanks for your input -

Beth

[+Airmapper]

Generally with a multi I enter the new coords as a waypoint and tell the unit to GO-TO.

 

Watching the coord numbers is a little hard isn't it? There are lots of people in the forums with E-trex's, they'll probably tell you how to enter stuff and the like.

[+Kerstin76]

You should have a look in the manual if your GPS can make a "projection". That will generate a waypoint in a specific distance with a specific bearing. You can use that to hunt in the same way as before.

[+IVxIV]

Sounds like you're not using the "goto" functionality of the GPSr, instead just heading out & matching your current displayed coords with that of the cache?

 

That's a do-able approach but a bit clunky lol. And, once at the first leg of a multi, I don't think there are any easy algorythms to fast-math coords 200 feet away, because it depends greatly on the compass bearing that 200 feet is taking you.

 

Perhaps the easiest way to go would be to "mark" your current location after arriving at multi-leg 1, then "project" from that marked coord to your 200 foot destination.. I imagine an eTrex Legend should be able to do something like that easily enough

[+Jhwk]

There is a formula, but because you are moving in three dimensions, I assume it would be unusable. Most GPSr's allow you to mark your location. Once you have done that you can tell your unit to goto that waypoint and then you want to walk in the direction opposite to the heading given to you (sometimes referred to as a back azimuth)

 

For instance, I just placed a new cache that the clues tell you to go 400 feet at 200 degrees from X (not really giving away my cache answer ) ANYWAY, I would mark my spot at X then I would walk away in the direction of 20 degrees (200-180 = 20) because my GPSr wants me to go to the X and I want to go to the projected waypoint - or the opposite direction. When I get 400 feet at 20 degrees I look for the container, or whatever I am supposed to be looking for.

 

An easier way is to carry a cheap compass. Mark your spot then walk towards then heading given and use your distance on the GPSr from your mark.

 

Clear as mud.

[+briansnat]

We've figured nothing out on our GPS yet (ETrex Legend) except how to watch the coords change as we get closer to the target

 

Thats an incredibly tedious way to do it. U should learn to input coordinates and to use the navigation screen

[+dkwolf]

Easiest way? Count your footsteps.

 

Start at home, stretch out a ruler and start pacing. A 6' male will stride about 3' per step, or 6' every time their left foot hits the ground. I shorten my stride just a touch when pacing, so every step is 2.5'.

 

How this works is, start with both feet at your baseline. Step out with your right foot first, then left. Every time your left foot hits the ground, count. Since my pacing stride is an easy multiple of 5, I count 5-10-15-20 etc etc etc. If your stride is a little different, say 3'/step, you can either count by 6's, or divide the distance you need to go by your step length (6'). 200 feet would equal 33 paces. at a 6' stride.

 

Once you have this figured out, when you're standing at the point that says 'go 200 feet in this direction', pick out an object--tree, rock, sign, whatever in that direction and start pacing. Walk directly towards that object and when you get close, start looking.

 

With a little practice, you can become quite accurate with this; I've done a lot of pacing on surveys at work and have found that when pacing 500' and then surveying the same distance with our equipment, I am usually within 5-10'. Just takes a little practice.

[+JohnnyVegas]

(Who has time to read the book? There are caches to find!)

And if you took the time to read bok you would be finding a lot more caches and less time looking. You really should use the goto feature it would things a lot easier. But this will require reading the book

 

This reminds of a customer I had once that wanted to buy a GPS, he said "I do not want to have to read the instructions, I want you to teach me" I told him I could set up private lessons but he did not want to pay for them. I sent him to another dealer.

Edited October 6, 2005 by JohnnyVegas

[+4leafclover]

We've figured nothing out on our GPS yet (ETrex Legend) except how to watch the coords change as we get closer to the target

 

Thats an incredibly tedious way to do it. U should learn to input coordinates and to use the navigation screen

I found about 60 caches this way, cause I never figured out the "goto" arrow screen!

 

now I love it...

[+Team Wiggy]

4leafclover wrote:

I found about 60 caches this way, cause I never figured out the "goto" arrow screen!

We've scored 54 finds in the last 30 days and thought we were doing good! But I have to admit JohnnyVegas (along with others) makes a very good point:

And if you took the time to read bok you would be finding a lot more caches and less time looking. You really should use the goto feature it would things a lot easier. But this will require reading the book

So all right... I'm off to dig it out of the packaging...

[+budd-rdc]

Comments regarding the GPSr's projection feature: On my eTrex Summit, I can only project in 0.1 mile increments, and many other GPSr's have the same restriction, so you'll have a tough time using that accurately. However, this is a very useful for projecting to a target far enough away where you can't see it.

 

Unless your eyes are impaired, you should be able to judge 200' quite accurately with practice. As for the direction, have a regular compass handy. If you are desperate, use other references like street alignment, or your own shadow.

 

You can also project in reverse. Mark your position on your GPSr, and click on the "Go To" button, and start walking to the next point. As you walk away, you'll see the distance and bearing to the location you started from. Add or subtract 180° to the bearing to get your heading.

 

There are software that can calculate projection for you. On your PC, fizzymagic has written Geocalc. Some cachers in our area have been known to "drylab" all the projections at home, and have all the coordinates calculated ahead of time. It's also possible similar software exists that will run on your PDA, so you can do this on the field.

Edited October 6, 2005 by budd-rdc

[+Sputnik 57]

So many replies. So few answers.

 

Take a look at Markwell's answer.

[+StarBrand]

More practical answer:

 

learn to use the compass arrow screen (goto feature)

Get to Ground Zero (listed Coordinates)

Use compass to find aaprox bearing you need to walk

Walk that way until GPSr compass screen says you are 200 feet from coordinates

 

Better answer:

 

learn to use the compass arrow screen (goto feature)

Get to Ground Zero (listed Coordinates)

Learn to project a waypoint using your GPSr - (hope you don't have the .1 restriction)

[rynd]

Hit the man overboard button or it's equivilent and start walking.

[rynd]

On my eTrex Summit, I can only project in 0.1 mile increments

1 mile = 5280 feet

.1 mile = 528.0 feet

.01 mile = 52.80 feet

[+Sputnik 57]

On my eTrex Summit, I can only project in 0.1 mile increments, and many other GPSr's have the same restriction, so you'll have a tough time using that accurately.

I used to think this about my 60C too. I'm not sure about the Summit or the Legend, but on the 60C and related models, when projecting a waypoint (MARK->MENU->Project Waypoint), cursor over to the little 'mi' in the lower right corner and hit ENTR. A hidden menu pops up right there and lets you change the projection units to mi, ft, yd, km, m, nm. From there, you can select miles, feet, yards, kilometers, meters or nautical miles.

 

Here's a screen shot from cacher jotne

[+whitecrow]

On the legend, highlight the waypoint that is shown on the map screen.

Push on the page button (upper right on etrex legend), the waypoint info page will come up.

Left click the click stick twice to select page edit. (small icon, upper right of the screen will light up)

push the click stick, then select "project waypoint", enter distance & brg.

 

The easier way is to look at page26 in the manual.

That little click stick is your friend!

Edited October 7, 2005 by whitecrow

[+Thot]

What I'm wondering is... is there a correlation or a formula between the coords and feet?  Is there a way to figure out that 200 feet changes the coordinate by x amount of degrees

Unless I missed it in all those replies no one answered his question.

 

There definitely is a formula, but it requires trigonometry. If you still want it I'll post it. A quick and dirty way to convert coordinates to feet is; every last digit of the coordinates is about 6 feet. If you are traveling due north on a line of longitude (a meridian) this does not change, but if you are traveling on a line of latitude (a parallel) it decreases as your latitude is further from the equator. Again for rough estimating where you are in California using about 6 feet per thousandths of a minute (one point in the last decimal place of the coordinate) will give a rough estimate of the distance.

 

As everyone has said, finding caches by watching the raw coordinates change is a painful way to do it.

Edited October 7, 2005 by Thot

[+Airmapper]

Watching the coords change is way more hassle than entering the coords manually into your unit. Crack the manual and you'll find out there are easier ways to go caching.

[+EScout]

This is a projection exercise.

On your Legend choose the starting point, a waypoint already saved in your Legend. Push lower left button, then Find>Nearest Waypoint>click on waypoint. On the waypoint page, click on the menu at the top, left, then choose "Project Waypoint"

Choose the distance, in one-hundredths of a mile (each .01 is 52.8 feet). In your case it is 200 feet, so set it to .04 which is 211.1 feet. Set the bearing direction. (you have previously set your Heading on the Main menu/Setup to magnetic or True north depending on what was specified.) Name this new projected waypoint and push OK.

Now bring up this waypoint and push Goto. It will bring you to 11 feet past the cachepoint, with typical margin of error. Good luck and let us know how you do.

[+Team Wiggy]

Thanks everyone for taking the time to give me your input on this topic... I spent a good chunk of time yesterday getting out the manual, reading (a lot of) it, and playing around with my GPSr. Manually added waypoints for the first time* so we'll see if we've got the hang of it this afternoon.

 

*Not difficult to do, but tedious. I can see why people so heavily encourage use of software and downloads... but that's another topic that I know has been widely discussed so I'll look into that after I get this hurdle crossed. []

 

Thanks again ~

Beth

[+Prime Suspect]

This is a projection exercise.

On your Legend choose the starting point, a waypoint already saved in your Legend. Push lower left button, then Find>Nearest Waypoint>click on waypoint. On the waypoint page, click on the menu at the top, left, then choose "Project Waypoint"

Choose the distance, in one-hundredths of a mile (each .01 is 52.8 feet). In your case it is 200 feet, so set it to .04 which is 211.1 feet. Set the bearing direction. (you have previously set your Heading on the Main menu/Setup to magnetic or True north depending on what was specified.) Name this new projected waypoint and push OK.

Now bring up this waypoint and push Goto. It will bring you to 11 feet past the cachepoint, with typical margin of error. Good luck and let us know how you do.

For GPS units that don't allow projection distances in feet, you'll get better accuracy by switching your GPS to metric distances. So, instead of using 0.04 miles (211 feet), you would enter 0.06 km (197 feet).

 

Maximum error using miles = 26.4 feet

Maximum error using kilometers = 16.4 feet

 

And if you're chaining together multiple projections, the errors can really add up.

[+Airmapper]

Thanks everyone for taking the time to give me your input on this topic... I spent a good chunk of time yesterday getting out the manual, reading (a lot of) it, and playing around with my GPSr. Manually added waypoints for the first time* so we'll see if we've got the hang of it this afternoon.

 

*Not difficult to do, but tedious. I can see why people so heavily encourage use of software and downloads... but that's another topic that I know has been widely discussed so I'll look into that after I get this hurdle crossed. []

 

Thanks again ~

Beth

It may be tedius, but I think you'll enjoy the ability to just use the arrow and distance readout to find a cache. It allows you a little more freedom to look for the cache while you are using the GPS.

 

Have fun.

[Major Catastrophe]

If you're at a point and need to go 200 feet at 30 degrees, first set a waypoint on your GPS (if it isn't there already) at the starting point. Then go off in approximately the right direction and wander around until the GPS says your initial point is 200 feet away at 210 degrees!

[+cudlecub]

I may not understand what's being said but I am seeing that you want to go 200' West from point A. I use a GPSMap76c and I would leave the waypoint in for point A and travel west until I was showing 200' from point A.