groundTrack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。
The places straight under a satellite from one moment to another: its ground track. Use a pass's start.ms and end.ms for the track of one pass, to draw on a globe.
インポート
import { groundTrack } from "@johnmorrisdotca/chikyu-earth/passes";定義
function groundTrack(set: ElementSet, fromMs: number, toMs: number, stepSeconds?: number): GroundPoint[]引数
| 名前 | 型 | 説明 |
|---|---|---|
set | ElementSet | The satellite's elements. |
fromMs | number | The first moment, milliseconds since the Unix epoch. |
toMs | number | The last moment. |
stepSeconds (省略可) | number | Seconds between points (10 by default). |
戻り値
GroundPoint[]
The points, in time order; a moment SGP4 gives no place for is left out.
例
import { groundTrack } 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 noon = Date.UTC(2026, 10, 3, 12);
const track = groundTrack(iss, noon, noon + 10 * 60_000);
console.log(track.length, Math.abs(track[0]!.lat) < 52);61 true出力（このページを作ったときに実行した結果）
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。