/**
 * astroengine validated ranges -- the measured spans behind the headline, and
 * the delta-T uncertainty that bounds what any ephemeris can say about ancient
 * dates.
 *
 * The engine's analytic series (VSOP87D, Meeus Moon/Pluto, the Kepler pack)
 * return numbers at any epoch; what is *validated* is narrower and per body.
 * This module is the one source of truth for those spans (mirroring
 * `docs/range-expansion.md` and `accuracy.json` -- "validated, not asserted":
 * the figures move only when the Horizons measurement does), consumed by
 * {@link engineCapabilities} for introspection and by chart assembly for
 * per-chart warnings.
 *
 * It is a leaf module (imports only core types) so both `chart.ts` and
 * `capabilities.ts` can use it without an import cycle.
 */
import type { EngineData, ChebData } from "./core.js";
/** A calendar-year span, inclusive. */
export interface BodySpan {
    from: number;
    to: number;
}
/** The measured headline band. The label is registry-pinned to accuracy.json.
 *  1000-3000: every body is packed across the span and measures sub-arcsecond
 *  on the frame-free basis (range-expansion.md Tier C); the ~3.3" uniform
 *  apparent floor is the IAU76/80-vs-Vondrak2011 frame term, not position
 *  error. The small bodies are fitted 1600-2484 (Horizons serves them only
 *  ~1600-2500) and report that narrower span via engineCapabilities. */
export declare const HEADLINE: BodySpan;
export declare const HEADLINE_LABEL = "1000-3000";
/** Measured spans that are narrower or wider than the headline
 *  (docs/range-expansion.md's table). */
export declare const MEASURED: Record<string, BodySpan>;
export declare const VSOP_BODIES: Set<string>;
/** Analytic points with no stated range bound (docs/range-expansion.md). */
export declare const ANALYTIC_BODIES: Set<string>;
/** Approximate calendar year for a Julian Day (for reporting spans). */
export declare function jdYear(jd: number): number;
/** A pack's fitted span in calendar years (`jd0 + segments * seg_days`). */
export declare function packSpan(pack: ChebData): BodySpan;
/**
 * The measured validated span for a body under the given engine data, or
 * `null` for analytic points with no stated bound and unknown (synthetic)
 * bodies. Packed bodies report the headline: outside their *fitted* span
 * they are not computed at all (they land in `Chart.unavailable`), so the
 * validated question only arises inside it.
 */
export declare function validatedSpanFor(body: string, data: EngineData): BodySpan | null;
/**
 * One-sigma uncertainty of delta T (TT - UT1) in seconds at a calendar year.
 *
 * Breakpoints from Morrison & Stephenson, "Historical values of the Earth's
 * clock error deltaT and the calculation of eclipses" (J. Hist. Astron. 35,
 * 2004), Table 1's sigma column; the telescopic era tapers to the IERS
 * measured span (effectively exact), and the future grows quadratically from
 * the end of the measured tables (extrapolation, stated as such). Linear
 * interpolation between breakpoints.
 *
 * This is what bounds ancient charts: at year 150 the position theories are
 * fine but sigma(deltaT) is minutes, which smears the fast movers -- the
 * Ascendant/MC rotate 0.25 deg per minute of clock error and the Moon moves
 * 0.55 arcsec per second -- while Jupiter barely notices. Chart warnings
 * report exactly that split.
 */
export declare function deltaTSigma(year: number): number;