tle2文件转czml文件

node_modules/julian/index.js

@@ -0,0 +1,31 @@
+module.exports = convert;
+module.exports.toDate = convertToDate;
+
+module.exports.toJulianDay = toJulianDay;
+module.exports.toMillisecondsInJulianDay = toMillisecondsInJulianDay;
+module.exports.fromJulianDayAndMilliseconds = fromJulianDayAndMilliseconds;
+
+var DAY = 86400000;
+var HALF_DAY = DAY / 2;
+var UNIX_EPOCH_JULIAN_DATE = 2440587.5;
+var UNIX_EPOCH_JULIAN_DAY = 2440587;
+
+function convert(date) {
+  return (toJulianDay(date) + (toMillisecondsInJulianDay(date) / DAY)).toFixed(6);
+};
+
+function convertToDate(julian) {
+  return new Date((Number(julian) - UNIX_EPOCH_JULIAN_DATE) * DAY);
+};
+
+function toJulianDay(date) {
+  return ~~((+date + HALF_DAY) / DAY) + UNIX_EPOCH_JULIAN_DAY;
+};
+
+function toMillisecondsInJulianDay(date) {
+  return (+date + HALF_DAY) % DAY;
+};
+
+function fromJulianDayAndMilliseconds(day, ms) {
+  return (day - UNIX_EPOCH_JULIAN_DATE) * DAY + ms;
+};