Projecting Waypoints...

[+TeamVilla5]

...and in what circumstances is it helpful? Color me clueless... TIA!

 

Happy Caching!

Lori V.

TeamVilla5

 

Edit: Because it's too early to catch typo's...

Edited February 1, 2006 by TeamVilla5

[+Airmapper]

Some caches require you project a waypoint in order to find it.

 

Projecting a waypoint wold be: When you are at a certain spot, using your GPS, or another method, you would for example go 200 feet @ bearing 245 degrees. This can be done on most GPSr's by using the arrow and the bearing/ distance readout.

 

I suppose you could also use a compass and pace it off, but if there are any obstacles this would be difficult to do with any accuracy.

Edited February 1, 2006 by Airmapper

[+Robespierre]

It's basic geometry:

 

circum. + pi x 2r / or pi x diam.

area = pi rsquared

pythag. a squared + b squared = c squared

etc.

[+BBWolf+3Pigs]

Projecting a waypoint takes a waypoint already on your GPSr, and projects it, typically some distance at a given bearing (true or relative).

 

I have used for for some multi-caches. Stage 1 is some interesting object such as a statue of historical marker. Then I have the cacher take some numbers from the statue or marker to come up with a bearing and range to offset. The final cache is at the projected waypoint.

 

This a great way to get people to a significant item, but one where you can't hide an item.

 

The two receivers I have had make it very easy to do so, in a variety of units (feet, yards, meters, mile, nautical miles, true bearing, magnetic bearing, etc).

[+BigFurryMonster]

A typical application in multicaches:

 

Go to point A

 

Then, project point B from there.

B is at X meters in direction D degrees.

 

Go to point B

[+Prime Suspect]

If you GPS doesn't have a waypoint projection function, you can still "fake it".

 

For example, you're standing at point A, and need to project a point 500' at 90°. Mark your current location and do a go-to to it. Start walking due east until your GPS says that waypoint A is 500' away at 270°. You're now 500' at 90° from point A.

[+wesleykey]

I suppose you could also use a compass and pace it off, but if there are any obstacles this would be difficult to do with any accuracy.

This is the way I always do it.... Maybe I'm getting old???

[+Pablo Mac]

I have a simple distance & bearing aspect to my Land Navigation 101 cache, and I am amazed at the amount of hand-holding some cachers have been begging for. I would hate to see them get lost deep in the woods because they relied too much on their nifty-neato GPSr and didn't bother to brush up on their basic land navigation knowledge & skills.

[+BigWhiteTruck]

I suppose you could also use a compass and pace it off, but if there are any obstacles this would be difficult to do with any accuracy.

More obstacles = more reference points.

[+ibycus]

One thing that hasn't really been specified here, that bears repeating, it to be careful of the bearing. A metre is a meter is a metre ( ), but a bearing of 123 could be any number of things.

 

1. It could be relative to magnetic north

2. It could be relative to true north

3. It could be relative to grid north

4. It could be relative to some other point of reference (relative to the direction of travel for example)

 

Most of the time this is just a matter of picking the right setting in your GPS. Personally though, I like to use grid north, and most people around here use true north. Depending on the distance you're projecting, this may or may not make a lot of difference.

[+EScout]

As Ibycus says, the cache hider should specify True or Magnetic, Mils or degrees.

[+CharlieP]

...and in what circumstances is it helpful?

As others have posted, projecting a waypoint may be necessary to find some geocaches where a range and bearing are used to define a position. But another useful application is for determining the position of a cache placed in a location with poor GPS reception. Lets say you are placing a cache under heavy tree cover and GPS reception is nil at the cache. Move to a nearby spot in the open and get the coords at that waypoint. Then use a compass to get the bearing to the cache and pace off the distance. By projecting the waypoint in the open to the cache location you can determine accurate coords for the cache. On my Garmin GPS76 I use the Measure Distance function to project waypoints.

 

FWIW, CharlieP