How Do Calculate

[AK0B]

How do you determine the coordinates of a new location when you know the Lat and Long of a cache and looking for a new location that is X feet and some angle Q degrees from the known point ?

 

Is there a computer program one can use.

[gm100guy]

If you could tell us what gps you have then we could let you know if it has the common feature that lets you project a waypoint from where you are to another spot using the distance and degrees from that location.

 

[AK0B]

Magellan SporTrak Pro

[gm100guy]

manual for gps

 

If you don't have the manual to explain this operation you can download it from this page.

 

It was slo for me so I could not look it up.

 

[+mtn-man]

I'm moving this to the GPS Units and Software Forum.

This is not a topic for Organized Geocaching.

[+katguy]

On the PC you can use FizzyMagic's GeoCalc program. On the SportTrak projection is found on the menu off of the position screen. Note: projection in feet does not seem to be selectable, but you can fool the unit by initially entering a small distance like 0.03 mi. The unit then shifts itself to ft and you can then enter the number you really want. I'm using firmware 4.06, YMMV .

Edited May 3, 2004 by katguy

[+Prime Suspect]

Forward Inverse

This is the windows version of the program used by the National Geodetic Service. You can give it two points and it will give you the distance and direction, or a point and distance and direction, and it will return the new coordinate. 26 different ellipsoids (including WGS-84, of course). Output in degrees (decimal degrees, decimal minutes, or degree/minute/seconds) or gradiants. Distances in meters, US feet, Intnl feet, Kilometers, US miles, Intnl miles, or Nautical miles.

[+Stunod]

A simple way to do this in the field is to set a GOTO to the coords you were given and then move to a position that shows you the right number of feet away at the OPPOSITE angle.

 

For example: if you need to be 123 feet at a bearing of 45 degrees, position yourself at the location that makes your GPS show you to be 123 feet at bearing 225 from your programmed waypoint.

 

EDIT: Got GPS caught my math error...corrected bearing.

Edited May 3, 2004 by Stunod

[+GOT GPS?]

That looks like a 90 deg angle, isn't the opposite supposed to be 225 degrees, which is 180 deg from 45 deg?

[+Stunod]

That looks like a 90 deg angle, isn't the opposite supposed to be 225 degrees, which is 180 deg from 45 deg?

DOH...my bad. Original post edited.