Merge pull request #401 from observerly/feature/wcs/SIP2DParameters

feat: add SIP2DParameters type to wcs module in @observerly/astrometry
observerly · Nov 12, 2024 · 10c91f1 · 10c91f1
2 parents 0046946 + 889e7da
commit 10c91f1
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diff --git a/src/wcs.ts b/src/wcs.ts
@@ -1,11 +1,25 @@
 /*****************************************************************************************************************/
 
 // @author         Michael Roberts <[email protected]>
-// @package        @observerly/astrometry/vsop87
-// @license        Copyright © 2021-2023 observerly
+// @package        @observerly/astrometry/wcs
+// @license        Copyright © 2021-2025 observerly
 
 /*****************************************************************************************************************/
 
 export type {}
+/*****************************************************************************************************************/
+
+// SIP (Simple Imaging Polynomial) is a convention used in FITS (Flexible Image Transport System)
+// headers to describe complex distortions in astronomical images. It extends the standard World
+// Coordinate System (WCS) by introducing higher-order polynomial terms that account for non-linear
+// optical distortions, such as those introduced by telescope optics or atmospheric effects.
+// @see https://fits.gsfc.nasa.gov/registry/sip/SIP_distortion_v1_0.pdf
+export type SIP2DParameters = {
+  AOrder: number
+  APower: { [key: string]: number }
+  BOrder: number
+  BPower: { [key: string]: number }
+}
+
 
 /*****************************************************************************************************************/
diff --git a/tests/wcs.spec.ts b/tests/wcs.spec.ts