Calculating distance from lat/long

[vetbridge]

I am making a signpost thingie for my yard that will have directional arrows pointing toward places I like, along with the distance in miles/kilometers. For example, there will be a Hilton Head, SC arrow and a Sint Maarten arrow. I will use a compass to approximate the direction each sign points, but how do I determine distance?

I have entered the locations into GoogleEarth, so I have the longitude/latitude for each point, as well as the lat/long for my house. How do I go from that to distance?

Thanks.

[beowulff]

@vetbridge

I am making a signpost thingie for my yard that will have directional arrows pointing toward places I like, along with the distance in miles/kilometers. For example, there will be a Hilton Head, SC arrow and a Sint Maarten arrow. I will use a compass to approximate the direction each sign points, but how do I determine distance?

I have entered the locations into GoogleEarth, so I have the longitude/latitude for each point, as well as the lat/long for my house. How do I go from that to distance?

Thanks.

Here ya’ go: http://jan.ucc.nau.edu/~cvm/latlongdist.html

[vetbridge]

Thanks! Easier than I could have dreamed.

[GaryM]

Another source of data.

How Far Is It?

[butler1850]

@vetbridge

I am making a signpost thingie for my yard that will have directional arrows pointing toward places I like, along with the distance in miles/kilometers. For example, there will be a Hilton Head, SC arrow and a Sint Maarten arrow. I will use a compass to approximate the direction each sign points, but how do I determine distance?

I have entered the locations into GoogleEarth, so I have the longitude/latitude for each point, as well as the lat/long for my house. How do I go from that to distance?

Thanks.

Use the measuring tool… it’ll get you “close enough” to the center of a city, and when you zoom in on the path, you’ll get a good indication of the “great circle route departure bearing.” The measuring tool defaults to showing a great circle when you measure long distance across the globe.

[UncleRojelio]

The next time you are in need of these type of calculations but have lost the above links, search for “Great Circle Calculation”.

[vetbridge]

spherical coordinates used by mathematicians and physicists, usually when considering other spheres than the Earth’s surface, the great-circle distance is found as follows. If \varphi;! is the azimuthal angle and heta;! the colatitude, then the spherical distance is given by

\begin{align}{\color{white}\frac{\Big|}{|}}r,\Delta\widehat{\sigma} &=2r\arcsin\left(\sqrt{\sin^2\left(\frac{ heta_f- heta_s}{2}\right)+\sin( heta_s)\sin( heta_f)\sin^2\left(\frac{\Delta\varphi}{2}\right)}\right),\ &=r\arctan\left(\frac{\sqrt{\left(\sin heta_f\sin\Delta\varphi\right)^2+\left(\sin heta_s\cos heta_f-\cos heta_s\sin heta_f\cos\Delta\varphi\right)^2}}{\cos heta_s\cos heta_f+\sin heta_s\sin heta_f\cos\Delta\varphi}\right);\end{align};!

I like pie, not pi!

[control-z]

Google Earth has a Ruler tool on the toolbar that will tell you the distance.