does any one know how to calculate latitude and longitude?

Question

from point a to point b knowing both latitude and longitude of both points
its for my oceanography class

Answer 1

If θ is the latitude in degrees and Φ is the longitude in degrees, R can be approximated by
R = 6,356.750 + 21.385sin(90 - θ).
Let the coordinates be θ1,Φ1 and θ2,Φ2.
The longitudinal chord for these will be
c1 = 2Rsin((θ2 - θ1)/2)
where θ2 is the northernmost latitude.
The latitudinal chord will be
c2 = 2Rsin(90 - θ1)sin((Φ2 - Φ2)/2)
The Great Circle chord will be
c3 = √((2Rsin((θ2 - θ1)/2))^2 + (2Rsin(90 - θ1)sin((Φ2 - Φ1)/2))^2)
c3 = 2R√((sin^2((θ2 - θ1)/2))^2 + (sin^2(90 - θ1)sin^2((Φ2 - Φ1)/2)))
The central angle will be
sin(α/2) = c2/2R = √((sin^2((θ2 - θ1)/2))^2 + (sin^2(90 - θ1)sin^2((Φ2 - Φ1)/2)))
Let R' = 6,356.750 + (21.385/2)sin(90 - θ1) + sin(90 - θ2).
Then the Great Circle arc can be approximated by
s = (4π/360)(6,356.750 + (21.385/2)sin(90 - θ1) + sin(90 - θ2)arcsin(√((sin^2((θ2 - θ1)/2))^2 + (sin^2(90 - θ1)sin^2((Φ2 - Φ1)/2)))

If simplification is desired, use R = 6,371 km:
s = (4π/360)(6,371)arcsin(√((sin^2((θ2 - θ1)/2))^2 + (sin^2(90 - θ1)sin^2((Φ2 - Φ1)/2)))

For a very rough apoproximation you can use
s = (2π/360)(6,371)√((θ2 - θ1)^2 + (Φ2 - Φ1)^2)

Answer 2

Calculate it from what? Are you trying to calculate latitude using a sextant and longitude with a chronometer using the Admiralty tables? It is much easier and cheaper - and more accurate - to buy a GPS unit these days.

Answer 3

yes buy a globe and its sorted every longitude and latitude is written there

Answer 4

Using what as your basis?