38 lines
1.2 KiB
Rust
38 lines
1.2 KiB
Rust
//! The propagated state of a satellite.
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use apsis_math::Vec3;
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/// The position and velocity of a satellite in the True Equator Mean Equinox
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/// frame.
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///
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/// Position is in kilometers and velocity is in kilometers per second. The
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/// frame is the one the model defines, with its first axis toward the mean
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/// equinox, its third axis along the true equator pole, and the second
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/// completing a right-handed set.
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#[derive(Debug, Clone, Copy, PartialEq)]
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pub struct State {
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/// Position, in kilometers.
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pub position: Vec3,
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/// Velocity, in kilometers per second.
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pub velocity: Vec3,
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/// The propagated semi-major axis, in kilometers.
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///
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/// This is the semi-major axis after the secular drag term has been
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/// applied, so it differs from the value implied by the mean motion in
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/// the element set.
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pub semi_major_axis: f64,
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}
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impl State {
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/// Returns the distance from the center of the Earth, in kilometers.
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pub fn altitude_radius(self) -> f64 {
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self.position.norm()
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}
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/// Returns the speed relative to the Earth's center, in kilometers per
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/// second.
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pub fn speed(self) -> f64 {
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self.velocity.norm()
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}
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}
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