Long. & Lat. calculation from initial point?

[whitenight541]

Hi all,

Given an initial point (longitude and latitude), a distance, and an angle of motion (in the 2d space), how can we calculate the coordinates (longitude and latitude) of the point that lies at that distance in the direction of that angle from the initial point?

 

[tiny-tim]

hi whitenight541!

are you talking about the surface of a sphere?

we use the formulas of spherical trigonometry (very similar to the ordinary triangle formulas) …

cosc = cosacosb + sinasinbcosC, and sina/sinA = sinb/sinB = sinc/sinC …

see http://en.wikipedia.org/wiki/Spherical_trigonometry#Identities"