`satelliteAt`関数

リファレンスの説明と例は英語です。見出しと目次は日本語です。

Where one satellite is in the sky over a place at one moment, and what the light is like: its direction and height, its distance, whether the Sun lights it, how high the Sun is, and how bright it looks.

インポート

import { satelliteAt } from "@johnmorrisdotca/chikyu-earth/passes";

定義

function satelliteAt(set: ElementSet, observer: Observer, ms: number, options?: Pick<PassOptions, "magnitudes">): (PassPoint & { sunlit: boolean; sunAltitude: number; magnitude: number | undefined; }) | undefined

引数

名前	型	説明
`set`	`ElementSet`	The satellite's elements.
`observer`	`Observer`	Where the watcher stands.
`ms`	`number`	The moment, milliseconds since the Unix epoch.
`options` (省略可)	`Pick<PassOptions, "magnitudes">`	`magnitudes` for your own standard magnitudes (the ISS, Tianhe and Hubble are known).

戻り値

(PassPoint & { sunlit: boolean; sunAltitude: number; magnitude: number | undefined; }) | undefined

Its place in the sky (altitude below 0 means below the horizon), sunlit, the Sun's altitude and the magnitude (undefined when it is in shadow or its standard magnitude is not known); undefined where SGP4 gives no place.

例

import { satelliteAt } from "@johnmorrisdotca/chikyu-earth/passes";

const iss = {
  OBJECT_NAME: "ISS (ZARYA)",
  EPOCH: "2026-11-02T10:25:21.580320",
  MEAN_MOTION: 15.49150046,
  ECCENTRICITY: 0.0007139,
  INCLINATION: 51.6332,
  RA_OF_ASC_NODE: 335.9757,
  ARG_OF_PERICENTER: 339.3739,
  MEAN_ANOMALY: 20.6961,
  NORAD_CAT_ID: 25544,
  BSTAR: 0.00012,
  MEAN_MOTION_DOT: 0.0001,
  MEAN_MOTION_DDOT: 0,
};
const where = satelliteAt(iss, { latitude: 51.5, longitude: -0.13 }, Date.UTC(2026, 10, 3, 12));
console.log(where?.compass, where?.altitude.toFixed(0));

WSW -38

出力（このページを作ったときに実行した結果）

ソースを見る GitHub で編集@johnmorrisdotca/chikyu-earth 0.51.1 のソースから作成しました。

この日本語は、まだ日本語を母語とする方の確認を受けていません。訂正を歓迎します。

satelliteAt関数

定義

引数

戻り値

例

`satelliteAt`関数