- #1
Kel1980
- 5
- 0
Hello,
I'm not a student, I'm just trying to figure out how to calculate coordinates on a globe, and I would like to ask for some help.
Let's say I have POINT A on the globe with the following coordinates:
POINT A
Latitude 45° 27' 50.95" N
Longitude 9° 11' 23.98" E
Also I have POINT B which is the Antipode:
POINT B
Latitude 45° 27' 50.95" S
Longitude 170° 48' 36.02" W
Given we are on a sphere (globe), from Point A to Point B for example I can draw 360 great circles, one for each single degree of the sphere:
- and the distance to go from Point A to Point B is 180° (first semi-circle)
- and the distance to go back from Point B to Point A is also 180° (second semi-circle)
Now let's say I have POINT C with the following coordinates:
POINT C
Latitude 45° 26' 48.53" N
Longitude 9° 1' 58.11" E
Given these information, THERE IS ONLY ONE GREAT CIRCLE which:
START IN POINT A
GOES THROUGH POINT C
ARRIVE IN POINT B (completing the first semi-circle of 180°)
COME BACK IN POINT A (completing the second semi-circle of 180°)
My problem is to find the formula to calculate the coordinates of the 2 Points which are half-way (90°) from Point A to Point B.
Let's call these 2 Points as M and N:
START in POINT A
GOES THROUGH POINT C
PASS THROUGH POINT M (at 90°)
ARRIVE IN POINT B (completing the first semi-circle of 180°)
PASS TO POINT N (at 270°)
COME BACK IN POINT A (completing the second semi-circle of 180°)
Which is the formula to calculate M and N?
On a - plain surface - i would have used the simple proportion of triangles to calculate them, but given is a sphere I don't know the formula to be applied.
I did some online search but I find a kind of difficult to figure it out.
I have been out of school from 15 years now, so I would like to ask if somebody can help me.
I hope my explanation is clear, thanks a lot if you can help!
Cheers
I'm not a student, I'm just trying to figure out how to calculate coordinates on a globe, and I would like to ask for some help.
Let's say I have POINT A on the globe with the following coordinates:
POINT A
Latitude 45° 27' 50.95" N
Longitude 9° 11' 23.98" E
Also I have POINT B which is the Antipode:
POINT B
Latitude 45° 27' 50.95" S
Longitude 170° 48' 36.02" W
Given we are on a sphere (globe), from Point A to Point B for example I can draw 360 great circles, one for each single degree of the sphere:
- and the distance to go from Point A to Point B is 180° (first semi-circle)
- and the distance to go back from Point B to Point A is also 180° (second semi-circle)
Now let's say I have POINT C with the following coordinates:
POINT C
Latitude 45° 26' 48.53" N
Longitude 9° 1' 58.11" E
Given these information, THERE IS ONLY ONE GREAT CIRCLE which:
START IN POINT A
GOES THROUGH POINT C
ARRIVE IN POINT B (completing the first semi-circle of 180°)
COME BACK IN POINT A (completing the second semi-circle of 180°)
My problem is to find the formula to calculate the coordinates of the 2 Points which are half-way (90°) from Point A to Point B.
Let's call these 2 Points as M and N:
START in POINT A
GOES THROUGH POINT C
PASS THROUGH POINT M (at 90°)
ARRIVE IN POINT B (completing the first semi-circle of 180°)
PASS TO POINT N (at 270°)
COME BACK IN POINT A (completing the second semi-circle of 180°)
Which is the formula to calculate M and N?
On a - plain surface - i would have used the simple proportion of triangles to calculate them, but given is a sphere I don't know the formula to be applied.
I did some online search but I find a kind of difficult to figure it out.
I have been out of school from 15 years now, so I would like to ask if somebody can help me.
I hope my explanation is clear, thanks a lot if you can help!
Cheers
Last edited: