rsw_quaternion
Defined in: lib.rs:61
fn rsw_quaternion(pos: &nalgebra::Vector3<f64>, vel: &nalgebra::Vector3<f64>) -> [Option<nalgebra::UnitQuaternion<f64>>](https://doc.rust-lang.org/std/option/enum.Option.html)
Compute the RSW (Radial / Along-track / Cross-track) orbital frame quaternion from satellite position and velocity in a simple Earth-centered inertial frame.
RSW basis (standard Vallado convention, right-handed):
- R̂ =
normalize(r)— radial (earth-to-satellite) - Ŵ =
normalize(r × v)— cross-track (orbit normal) - Ŝ =
Ŵ × R̂— along-track (circular prograde: roughly +v̂ direction)
Returns the RSW-to-ECI rotation as a unit quaternion, or None if
position/velocity are zero or parallel (degenerate orbit).
Axis order
Section titled “Axis order”This differs from the pre-redesign lvlh_quaternion which used axis
order [InTrack, CrossTrack, Radial]. The new RSW convention is
[Radial, Along-track, Cross-track]. The returned quaternion has
different numerical values; call sites that pin Lvlh values must be
updated to new RSW-basis expectations.