triangular cache

[+red ink]

i have an etrex vista cx, i have been told i can enter 2 different waypoint locations

and it will give me a waypoint for the third location. working on a triangular cache . is this true? and how do you do it, i have misplaced my owner manual, i donot know if its done by way point averaging or proximity search. the coord are n36 04.800 w09412.290 and n36 04.619 w094 12.293 thanks in advane for those who help.

[+steve p]

I can't answer the specific question, but since you misplaced your owners manual here's a link where you can download your unit's manual:

 

eTrex Vista Cx owners manual

 

Good luck.

[+StarBrand]

Your going to need some distance and/or bearing information as well in order to pin down some specific 3rd point.

[+ShadowAce]

The manual will show you how to 'project' a waypoint, but unless they made a change to the eTrex Vista it does not have the ability to triangulate anything other then your altitude.

[+Thrak]

i have an etrex vista cx, i have been told i can enter 2 different waypoint locations

and it will give me a waypoint for the third location. working on a triangular cache . is this true? and how do you do it, i have misplaced my owner manual, i donot know if its done by way point averaging or proximity search. the coord are n36 04.800 w09412.290 and n36 04.619 w094 12.293 thanks in advane for those who help.

 

In order to take two known waypoints and project another one you need both distance and bearing from the two known waypoints. That's triangulation.

 

I have a friend who wanted to give 3 waypoints and have you use ONLY that information to find his cache. This is trilateration. It's hard to do and, unless the known waypoints are fairly near to the unknown one, you will be way off due to the curvature of the earth.

[+the hermit crabs]

I have a friend who wanted to give 3 waypoints and have you use ONLY that information to find his cache.

 

You mean like this cache?

[+Formerly Dominoes]

 

In order to take two known waypoints and project another one you need both distance and bearing from the two known waypoints. That's triangulation.

 

The unknown corner could be calculated either by distance, or bearing. No need for both.

[+Thrak]

I have a friend who wanted to give 3 waypoints and have you use ONLY that information to find his cache.

 

You mean like this cache?

 

Yes, however I believe the 3 points for this cache are relatively near to each other so it can work. The one my friend was hoping to make had points around 30 miles away from the actual cache point. Trying to make sure it would work ended up putting me across the road in the middle of a field several hundred feet from the cache. His hide was a micro........

[+EScout]

You need a little more information. For example, if told it was an equilateral triangle, you now have enough info. Just take the bearing from one corner to the other, add or subtract 60 degrees and project the distance between the other two (which you have determined by entering these points in the route function of your GPSr.) In this example, there are actually two points that complete two triangles; look at which one makes the most sense or check them both out.

 

This is just one example. The additional piece of information can be a length of a side(s), different type of triangle. You need at least one more piece of info.

[+red ink]

You need a little more information. For example, if told it was an equilateral triangle, you now have enough info. Just take the bearing from one corner to the other, add or subtract 60 degrees and project the distance between the other two (which you have determined by entering these points in the route function of your GPSr.) In this example, there are actually two points that complete two triangles; look at which one makes the most sense or check them both out.

 

This is just one example. The additional piece of information can be a length of a side(s), different type of triangle. You need at least one more piece of info.

it is an icosoles triangle, the bearing is 117 degrees from apex to gz tks in advance

[+Formerly Dominoes]

You need a little more information. For example, if told it was an equilateral triangle, you now have enough info. Just take the bearing from one corner to the other, add or subtract 60 degrees and project the distance between the other two (which you have determined by entering these points in the route function of your GPSr.) In this example, there are actually two points that complete two triangles; look at which one makes the most sense or check them both out.

 

This is just one example. The additional piece of information can be a length of a side(s), different type of triangle. You need at least one more piece of info.

 

Oops, I stand corrected. If you only have the distances from the known two points, there will be two possible solutions. One on each side of the line between the two known points.

Edited August 22, 2007 by Formerly Dominoes