Matemathics, hard question.
 

Hi!

I'm looking for the correct equation for the distance between any 2 latitude and longitude pos on earth. Both the great circle and rhumb line between them.

Anyone knows any equation that can be used? It is do be inserted in a flight planning software.

Thanks!

Just a bit of spherical trigonometry. Nothing hard.

You'll have what you need on this:www.best.com/~williams/avform.htm

Thanks!
 

Thanks!

Great site.

Sorry for saying hard, but I wasn't sure about how much is tought on ATPL level.

Hard is always a relative word. :)

Isn't it the famous Dist= Diff Long x cos lat (mean)? Longitude converted to minutes.

Off the top of my head, that's the formula for the change in apparent track over the course of the great circle isn't it?

What formula is used?
 

What formula is used in flight computers on commercial airliners?
I'm looking for the formula that are granted for use in commercial navigation and calculations by the JAA.

I was doing some research into this a couple of years ago and came across this site http://williams.best.vwh.net/gccalc.htm
It offers 9 different predetermined "shapes" for the earth and also allows you to define your own!

WGS84
 

Yes, I got the site from an earlier post.

Is it WGS84 that is the approved geoid to use in aviation?

But the site doens't give a formula for it, does it? Only for a sphere?