Aleksandar

02-22-2012, 01:12 PM

Hi All,

Can anyone help me to convert coordinates from geocentric (polar) to local topocentric (Cartesian) coordinate-system?

If the center of the local topocentric system is at (R, Theta, Phi) in geocentric system, and the point is at (R, Theta+dTheta, Phi+dPhi), I need to calculate the position of the point (x,y,z) in the local topocentric system.

It should be done using finite difference calculus, since otherwise (using standard matrix representation) it can be numerically unstable and comprehensive to calculate.

Each coordinate depends on radius, latitude (Theta) and (finite) differential latitude and longitude. Something like this:

x = f(R, Theta, dTheta, dPhi)

y = g(R, Theta, dTheta, dPhi)

z = h(R, Theta, dTheta, dPhi)

Explanation:

The origin of a topocentric system is at a point on surface of the earth, with its x-axis point to to the East direction and the y-axis point to the North. The z-axis is pointing up perpendicular to the xy plane, having z coordinates analogous to heights. Therefore topocentric coordinates are often expressed by ENH (East North Height), analogous to x y and z coordinate.[/B]

Thank you in advance!

Can anyone help me to convert coordinates from geocentric (polar) to local topocentric (Cartesian) coordinate-system?

If the center of the local topocentric system is at (R, Theta, Phi) in geocentric system, and the point is at (R, Theta+dTheta, Phi+dPhi), I need to calculate the position of the point (x,y,z) in the local topocentric system.

It should be done using finite difference calculus, since otherwise (using standard matrix representation) it can be numerically unstable and comprehensive to calculate.

Each coordinate depends on radius, latitude (Theta) and (finite) differential latitude and longitude. Something like this:

x = f(R, Theta, dTheta, dPhi)

y = g(R, Theta, dTheta, dPhi)

z = h(R, Theta, dTheta, dPhi)

Explanation:

The origin of a topocentric system is at a point on surface of the earth, with its x-axis point to to the East direction and the y-axis point to the North. The z-axis is pointing up perpendicular to the xy plane, having z coordinates analogous to heights. Therefore topocentric coordinates are often expressed by ENH (East North Height), analogous to x y and z coordinate.[/B]

Thank you in advance!