Expand description
target-match — identify which catalogued sky object a telescope frame captured.
Given a pointing (right ascension / declination) and a field of view
(derived from optics, or supplied directly), target-match ranks a
caller-supplied set of catalogue objects by angular separation and returns
those that fall on the frame. Matching is done by sky position only, never
by name — a designation may ride along on a result for display, but it
never influences the match (capture software writes object names
inconsistently; coordinates are authoritative).
The crate is catalog-agnostic: it owns no catalogue data and performs no
I/O. A consumer brings its own objects — from a database, a file, a SIMBAD
resolver, or a hand-built list — by implementing the matcher crate’s
SkyObject trait, and target-match does the geometry.
§Modules
angle— angle and equatorial-coordinate primitives: decimal ⇄ sexagesimal (HH:MM:SS/±DD:MM:SS) parsing and formatting, and great-circle (haversine) angular separation.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— theSkyObjectinput trait, match constraints (radius, rectangular field of view, nearest-N), and deterministic ranking.
§Example
use target_match::{Angle, Constraint, Equatorial, Field, Optics, RadiusPolicy, SkyObject, rank};
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").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");§Status
Extracted from the nightwatch-astro/alm targeting pipeline; specified and
implemented under specs/001-target-match-core/ (SpecKit).
Re-exports§
pub use angle::precess;pub use angle::separation;pub use angle::Angle;pub use angle::Epoch;pub use angle::Equatorial;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;