Proximity Circles: software?

[+3-Melvins]

So in the interest of laziness, I'm wondering if anyone knows of software that will generate proximity circles?

 

ie, the cache is 150m from Waypoint A, 300m from Waypoint B, and 65m from Waypoint C...where is it?

 

Either a desktop app (ala EasyGPS) or a miracle product that can be uploaded to my Garmin eTrex Legend.

 

Any info appreciated, thx!

 

Meanwhile, I'll stick to using a pencil and my grey matter.

[+g-o-cashers]

ExpertGPS (the big brother to EasyGPS) will do that.

 

GO$Rs

[+trainlove]

Fizzycalc might allow you to do the math.

Delorme mapping software will do it.

I'd just convert to UTM coords, define the equations of circles of radius R1 at coordinate x1,y1, and 2, 3, ... And solve the simultaneous equations.

Or I'd just enter those points on my GPSr and manually find a spot that fits the requirements.

[+Timpat]

Since you are using a Garmin eTrex Legend you must have MapSource to load and manage waypoints and mapping. MapSource lets you set/create proximity circles. Create a waypoint, and under Waypoint Properties uncheck the "Unkown" box for Proximity. then enter in the needed distance.

 

If you want to change units (metric, statute) go into Edit/Preferences. you need to enter decimals of miles or kilometers but I found you can get it down within feet (meters) of what you need. Save this file and upload it to your Legend if you want. The proximity circle displays on screen.

[+Redwoods Mtn Biker]

OziExplorer will generate range rings.

[+Renegade Knight]

So in the interest of laziness, I'm wondering if anyone knows of software that will generate proximity circles?

 

ie, the cache is 150m from Waypoint A, 300m from Waypoint B, and 65m from Waypoint C...where is it?

 

Either a desktop app (ala EasyGPS) or a miracle product that can be uploaded to my Garmin eTrex Legend.

 

Any info appreciated, thx!

 

Meanwhile, I'll stick to using a pencil and my grey matter.

 

Any Free CAD program will do that. Heck any paid CAD program will do that as well.

[+Butano]

Here is an article in Wikipedia about trilateration, which is about finding a point as defined by three known points and the distance from those points. http://en.wikipedia.org/w/index.php?title=...oldid=251812552

[+DanOCan]

Since you are using a Garmin eTrex Legend you must have MapSource to load and manage waypoints and mapping. MapSource lets you set/create proximity circles. Create a waypoint, and under Waypoint Properties uncheck the "Unkown" box for Proximity. then enter in the needed distance.

 

Wow, I never noticed that option before. I feel like such an old dog learning a new trick. Thanks!

[+3-Melvins]

Hey, thanks All for the great info.

 

Timpat- I don't have Mapsource, are you saying it should come included with the GPSr? I bought mine last year and there were no such "treats" with it. I'm scoping out the Garmin site right now, and it does not appear to be downloadable either.

 

What am I missing?

 

Sorry for what are probably newbie questions, but- that's what I am!

 

Matt.

 

Since you are using a Garmin eTrex Legend you must have MapSource to load and manage waypoints and mapping. MapSource lets you set/create proximity circles. Create a waypoint, and under Waypoint Properties uncheck the "Unkown" box for Proximity. then enter in the needed distance.

 

If you want to change units (metric, statute) go into Edit/Preferences. you need to enter decimals of miles or kilometers but I found you can get it down within feet (meters) of what you need. Save this file and upload it to your Legend if you want. The proximity circle displays on screen.

[+Timpat]

Matt, it's has been so long ago since I bought my Legend but it did come with a CD with the Trip and Waypoint Manager software. I'm not certain now if this program acts like the other Garmin MapSource (MS)program. You might find US topo, or Canada Topo, for a small cost.

[+fizzymagic]

I have written an app that uses the classes from FizzyCalc to do this, but I hesitate to release it into the wild because it would make so many puzzle caches too easy.

 

I do it iteratively using a distance-squared metric and a simplex-based iterative minimization algorithm, if that is at all helpful. The good thing is that it works even if the distances are not exact.

 

I use the same basic technique to solve other similar problems, such as two angles, three equal distances, centroids, etc. Works like a champ.

[+Red90]

GE-Path does this in Google Earth

http://www.sgrillo.net/googleearth/

[+DustyWalker]

Since you are using a Garmin eTrex Legend you must have MapSource to load and manage waypoints and mapping. MapSource lets you set/create proximity circles. Create a waypoint, and under Waypoint Properties uncheck the "Unkown" box for Proximity. then enter in the needed distance.

 

If you want to change units (metric, statute) go into Edit/Preferences. you need to enter decimals of miles or kilometers but I found you can get it down within feet (meters) of what you need. Save this file and upload it to your Legend if you want. The proximity circle displays on screen.

 

Well that is just too cool. I frequently use my GPS to generate maps for court (hunting violations) and need to show a 400 m circle around a waypoint on the map. I didn't know Mapsource would do this. Thanks!