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Chikyu Earth地球

A line-drawn globe of the world's countries that turns at the Earth's own rate, with an optional realistic Earth from space and markers for any place.

Chikyu is the Japanese word 地球 for the Earth. About the name

Contents

Reference · Passes: when a satellite crosses the sky over a place

SatellitePasstype

One pass of a satellite over a place: it comes up through minAltitude, reaches its highest and goes down below minAltitude, with whether and how it can be seen. Times are UTC milliseconds; show them in the place's own time by adding its offset.

Import it

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

Definition

interface SatellitePass {
    noradId: number;
    name: string;
    start: PassPoint;
    highest: PassPoint;
    end: PassPoint;
    durationSeconds: number;
    visible: VisiblePart | undefined;
    reason: PassReason;
    sky: SkyName;
    sunAltitude: number;
    sunlit: boolean;
    magnitude: number | undefined;
    elementEpochMs: number;
    elementAgeDays: number;
    stale: boolean;
}

Members

NameTypeDescription
noradIdnumber
namestring
startPassPoint

The pass above minAltitude, lit or not.

highestPassPoint
endPassPoint
durationSecondsnumber
visibleVisiblePart | undefined

The part that can be seen, or undefined when none can.

reasonPassReason

visible, or why not.

skySkyName

The sky at the watcher's place, at the highest point of the visible part (or of the pass when none is visible).

sunAltitudenumber

The Sun's altitude then, degrees.

sunlitboolean

True when the satellite is in sunlight for at least part of the pass above minAltitude.

magnitudenumber | undefined

The brightest it is, as a magnitude (smaller is brighter), over the visible part or, when none is visible, over the part that is lit. Undefined when it is never lit or its standard magnitude is not known.

elementEpochMsnumber

The moment of the elements, milliseconds since the Unix epoch.

elementAgeDaysnumber

Days between the elements' moment and the pass's highest point (negative for a pass before it).

staleboolean

True when the elements are older than DEFAULT_DIM_AFTER_DAYS at the pass: its times are less sure.

Examples

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

const line = (pass: SatellitePass): string => `${pass.name}: ${pass.highest.altitude.toFixed(0)} degrees ${pass.highest.compass}, ${pass.reason}`;
console.log(typeof line);
function

What it prints (run when this page was built)

View sourceEdit on GitHubMade from the source of @johnmorrisdotca/chikyu-earth 0.51.1.