@observerly/astrometry
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observerly's lightweight, zero-dependency, type safe astrometry library written in Typescript for calculating the position of celestial objects in the sky.
105 lines (104 loc) • 2.9 kB
TypeScript
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import type { CartesianCoordinate, EquatorialCoordinate } from './common';
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export type SIP2DParameters = {
AOrder: number;
APower: {
[key: string]: number;
};
BOrder: number;
BPower: {
[key: string]: number;
};
};
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export declare const parseSIPTerm: (term: string, prefix: 'A' | 'B') => [number, number] | null;
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export type WCS = {
/**
*
*
* The central or reference pixel for the WCS, e.g., the central pixel of the image.
*
*
*/
crpix: CartesianCoordinate;
/**
*
*
* The central or reference equatorial coordinate for the WCS, corresponding to the pixel at the central reference pixel.
*
*
*/
crval: EquatorialCoordinate;
/**
*
*
* CD Matrix Element 1,1 for the WCS
*
*
*/
cd11: number;
/**
*
*
* CD Matrix Element 1,2 for the WCS
*
*
*/
cd12: number;
/**
*
*
* CD Matrix Element 2,1 for the WCS
*
*
*/
cd21: number;
/**
*
*
* CD Matrix Element 2,2 for the WCS
*
*
*/
cd22: number;
/**
*
*
* Constant term for the right ascension (from the Affine transformation matrix)
*
*
*/
E: number;
/**
*
*
* Constant term for the declination (from the Affine transformation matrix)
*
*
*/
F: number;
/**
*
*
* SIP (Simple Imaging Polynomial) parameters for the WCS
*
*
*/
SIP?: SIP2DParameters;
};
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/**
*
* convertPixelToWorldCoordinateSystem
*
* Converts a given image pixel to an equatorial coordinate base on the prescribed WCS
*
* @param wcs the World Coordinate System (WCS) parameters to use for the conversion
* @param pixel the pixel to convert to an equatorial coordinate, e.g., { x: 0, y: 0 }
* @returns the equatorial coordinate of a given pixel in the prescribed WCS
*/
export declare const convertPixelToWorldCoordinateSystem: (wcs: WCS, pixel: CartesianCoordinate) => EquatorialCoordinate;
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