Struct Aberration

pub struct Aberration {
    pub converged: bool,
    pub stellar: bool,
    pub transmit_mode: bool,
}

Represents the aberration correction options in ANISE.

In space science and engineering, accurately pointing instruments (like optical cameras or radio antennas) at a target is crucial. This task is complicated by the finite speed of light, necessitating corrections for the apparent position of the target.

This structure holds parameters for aberration corrections applied to a target’s position or state vector. These corrections account for the difference between the target’s geometric (true) position and its apparent position as observed.

Rule of tumb

In most Earth orbits, one does not need to provide any aberration corrections. Light time to the target is less than one second (the Moon is about one second away). In near Earth orbits, e.g. inner solar system, preliminary analysis can benefit from enabling unconverged light time correction. Stellar aberration is probably not required. For deep space missions, preliminary analysis would likely require both light time correction and stellar aberration. Mission planning and operations will definitely need converged light-time calculations.

For more details, https://naif.jpl.nasa.gov/pub/naif/toolkit_docs/C/req/abcorr.html.

SPICE Validation

The validation test validate_jplde_de440s_aberration_lt checks 101,000 pairs of ephemeris computations and shows that the unconverged Light Time computation matches the SPICE computations almost all the time. More specifically, the 99th percentile of error is less than 5 meters, the 75th percentile is less than one meter, and the median error is less than 2 millimeters.

Fields

converged: bool

Indicates whether the light time calculations should be iterated upon (more precise but three times as many CPU cycles).

stellar: bool

Flag to denote if stellar aberration correction is applied. Stellar aberration is due to the motion of the observer (caused by Earth’s orbit around the Sun).

transmit_mode: bool

Specifies whether in reception or transmission mode. True for ‘transmit’ mode, indicating the correction is applied to the transmitted signal from the observer to the target. False for ‘receive’ mode, for signals received from the target.

Implementations

impl Aberration

pub const NONE: Option<Aberration> = None

Disables aberration corrections, e.g. all translations are geometric only (typical use case).

pub const LT: Option<Aberration> = _

Unconverged light time correction in reception mode without stellar aberration (e.g. a ground station targeting a spacecraft near the Moon)

pub const LT_S: Option<Aberration> = _

Unconverged light time correction in reception mode with stellar aberration

pub const CN: Option<Aberration> = _

Converged light time correction in reception mode without stellar aberration

pub const CN_S: Option<Aberration> = _

Converged light time correction in reception mode with stellar aberration

pub const XLT: Option<Aberration> = _

Unconverged light time correction in transmission mode without stellar aberration (e.g. a Moon orbiter contacting a ground station)

pub const XLT_S: Option<Aberration> = _

Unconverged light time correction in transmission mode with stellar aberration

pub const XCN: Option<Aberration> = _

Converged light time correction in transmission mode without stellar aberration

pub const XCN_S: Option<Aberration> = _

Converged light time correction in transmission mode with stellar aberration

pub fn new(flag: &str) -> Result<Option<Aberration>, PhysicsError>

Initializes a new Aberration structure from one of the following (SPICE compatibility):

• NONE: No correction
• LT: unconverged light time, no stellar aberration, reception mode
• LT+S: unconverged light time, with stellar aberration, reception mode
• CN: converged light time, no stellar aberration, reception mode
• CN+S: converged light time, with stellar aberration, reception mode
• XLT: unconverged light time, no stellar aberration, transmission mode
• XLT+S: unconverged light time, with stellar aberration, transmission mode
• XCN: converged light time, no stellar aberration, transmission mode
• XCN+S: converged light time, with stellar aberration, transmission mode

Trait Implementations

impl Clone for Aberration

fn clone(&self) -> Aberration

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for Aberration

fn fmt(&self, f: &mut Formatter<'_>) -> Result<(), Error>

Prints this configuration as the SPICE name.

impl Default for Aberration

fn default() -> Aberration

Returns the “default value” for a type.

impl Display for Aberration

fn fmt(&self, f: &mut Formatter<'_>) -> Result<(), Error>

Formats the value using the given formatter.

impl PartialEq for Aberration

fn eq(&self, other: &Aberration) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl Copy for Aberration

impl Eq for Aberration

impl StructuralPartialEq for Aberration