Definition:Colatitude
Jump to navigation
Jump to search
Definition
In a spherical coordinate system, the colatitude $\theta$ of a point is the angle between the polar axis and the radius vector.
Terrestrial Colatitude
Let $J$ be a point on Earth's surface that is not one of the two poles $N$ and $S$.
Let $\phi$ denote the latitude of $J$.
The (terrestrial) colatitude of $J$ is the (spherical) angle $90 \degrees - \phi$, that is:
- if $J$ is in the northern hemisphere of Earth, the colatitude is the (spherical) angle $\sphericalangle NOJ$
- if $J$ is in the southern hemisphere of Earth, the colatitude is the (spherical) angle $\sphericalangle SOJ$.
Celestial Colatitude
Let $P$ be a point on the celestial sphere.
Let the celestial latitude of $P$ be $\beta$.
The celestial colatitude of $P$ is defined as:
- $90 \degrees - \beta$ when $P$ is closer to the north ecliptic pole
- $90 \degrees + \beta$ when $P$ is closer to the south ecliptic pole.
Also see
- Results about colatitude can be found here.
Sources
- 1998: David Nelson: The Penguin Dictionary of Mathematics (2nd ed.) ... (previous) ... (next): colatitude: 1.
- 1998: David Nelson: The Penguin Dictionary of Mathematics (2nd ed.) ... (previous) ... (next): spherical coordinate system
- 2008: David Nelson: The Penguin Dictionary of Mathematics (4th ed.) ... (previous) ... (next): colatitude: 1.
- 2008: David Nelson: The Penguin Dictionary of Mathematics (4th ed.) ... (previous) ... (next): spherical coordinate system