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Crate target_match

Crate target_match 

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Expand description

Identify which catalogued sky objects a telescope frame covers, given a pointing (right ascension / declination) and a field of view (derived from optics, or supplied directly).

A caller-supplied set of catalogue objects is ranked by angular separation from the pointing; objects inside the frame’s membership shape are flagged. Matching uses sky position only — a designation may ride along on a result for display, but it never influences the match.

The crate holds no catalogue data and performs no I/O. A consumer supplies its own objects — from a database, a file, a name resolver, or a hand-built list — by implementing the matcher module’s SkyObject trait.

Coordinate and angle types come from the skymath crate and appear directly in this crate’s signatures: construct positions with skymath::Equatorial and angles with skymath::Angle. The crate is re-exported as target_match::skymath so consumers can name a version-matched skymath without a separate dependency entry.

§Modules

  • optics — plate scale and field-of-view geometry from focal length, pixel size (x/y), binning (x/y), and sensor dimensions — or a directly supplied pixel scale / field of view — plus the search-radius policies.
  • matcher — the SkyObject input trait, match constraints (radius, rectangular field of view, nearest-N), and deterministic ranking.

§Example

use skymath::{Angle, Equatorial, ParseMode};
use target_match::{rank, Constraint, Field, Optics, RadiusPolicy, SkyObject};

struct Target { name: &'static str, ra: f64, dec: f64 }
impl SkyObject for Target {
    fn position(&self) -> Equatorial {
        Equatorial::j2000(Angle::from_degrees(self.ra), Angle::from_degrees(self.dec)).unwrap()
    }
}

let catalog = [
    Target { name: "M 31",  ra: 10.6847, dec: 41.2688 },
    Target { name: "M 33",  ra: 23.4621, dec: 30.6599 },
];
let pointing = Equatorial::parse_j2000("00:42:44.3", "+41:16:09", ParseMode::Strict).unwrap();
let field = Field::from_optics(Optics {
    focal_mm: 800.0, pixel_um: (3.76, 3.76), binning: (1, 1), pixels: (6248, 4176),
}).unwrap();

let hits = rank(pointing, &catalog, Constraint::within(&field, RadiusPolicy::Circumscribed).nearest_one());
assert_eq!(hits[0].object.name, "M 31");

Re-exports§

pub use error::Error;
pub use error::Result;
pub use matcher::is_framed;
pub use matcher::rank;
pub use matcher::Constraint;
pub use matcher::Match;
pub use matcher::Matcher;
pub use matcher::Membership;
pub use matcher::Offset;
pub use matcher::Query;
pub use matcher::SkyObject;
pub use optics::Field;
pub use optics::Optics;
pub use optics::RadiusPolicy;
pub use optics::ARCSEC_PER_DEGREE;
pub use optics::ARCSEC_PER_RADIAN;
pub use optics::DEFAULT_FALLBACK_RADIUS;
pub use skymath;

Modules§

error
Error type for target-match.
matcher
The matching engine: input trait, constraints, ranking, and a prebuilt index.
optics
Plate scale and field-of-view geometry.