Determining distance between two coordinates – Wisconsin Geocaching Association

This topic has 9 replies, 6 voices, and was last updated 16 years, 1 month ago by Team Black-Cat.

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12/10/2009 at 12:36 am #1729241

Todd300
Member

How do I determine the distance between two sets of coordinates by using math, not a GPS? Doing this will help me on the way to solve a puzzle. Thanks 🙂

12/10/2009 at 2:28 am #1917980

hogrod
Member

You can use the program FizzyCalc (free) to do this for you. once you have the program I believe what you are looking for is under the distance tab.

http://www.fizzymagic.net/Geocaching/FizzyCalc/

12/10/2009 at 3:17 pm #1917981

Team Deejay
Member

If you are working on the puzzle that I think you are working on, pay close attention to the description and hints. Some people’s view of the world is skewed, similar to that of people in the 12th century. I wonder if they were worried about sailing off the edge of the world!

12/10/2009 at 5:59 pm #1917982
Team Black-Cat
Member
Unless you REALLY need to do the math, you should probably find an online utility to get the distance.

But since you asked…
I recently created a function for a program I’m working on. Here’s what I did.
Keep in mind that I am a programmer and not a mathmatician…

Start with decimal degrees instead of degrees and minutes. You can do the conversion on GC.com.

Convert each coordinate to radians:
```
A=(Point1Latitude * Pi /180)

B=(Point1Longitude * Pi /180)

C=(Point2Latitude * Pi /180)

D=(Point2Latitude * Pi /180)
```
Get the difference between the angles:
```
DLat=C-A

DLon=D-B
```
Now it gets fun…
```
X = Sin(DLat / 2) * Sin(DLat / 2) + Cos(A) * Cos(C) * Sin(DLon / 2) * Sin(DLon / 2)

Y = 2 * Atan2(Sqrt(X), Sqrt(1 - X))
```
To get miles, multiply Y by 3959.

Did I get it right Mathman?

Edited to add:
Atan2 might not be on your calculator. It is the angle whose tanget is the quotent of the two specified numbers.
12/10/2009 at 7:51 pm #1917983
CodeJunkie
Member
@Team Black-Cat wrote:
```
A=(Point1Latitude * Pi /180)

B=(Point1Longitude * Pi /180)

C=(Point2Latitude * Pi /180)

D=(Point2Latitude * Pi /180)
```
I assume you meant Point2Longitude for D.
12/10/2009 at 10:19 pm #1917984

Team Black-Cat
Member

Yes I did, and thanks for catching that. I can’t edit the original post anymore…

12/11/2009 at 5:44 pm #1917985

Team Black-Cat
Member

The hard way
The easy way

12/12/2009 at 12:05 am #1917986

Miata
Member

@Team Black-Cat wrote:

The hard way
The easy way

Much better……

12/12/2009 at 4:43 am #1917987

CodeJunkie
Member

For a whole bunch of different versions of this, do a “Google” search using the following words:
gps distance calculator

12/12/2009 at 6:04 am #1917988

Team Black-Cat
Member

@CodeJunkie wrote:

For a whole bunch of different versions of this, do a “Google” search using the following words:
gps distance calculator

If you’re having trouble sleeping, search for “haversine”.
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