tle2文件转czml文件

node_modules/satellite.js/lib/propagation/initl.js

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+/*!
+ * satellite-js v5.0.0
+ * (c) 2013 Shashwat Kandadai and UCSC
+ * https://github.com/shashwatak/satellite-js
+ * License: MIT
+ */
+
+"use strict";
+
+Object.defineProperty(exports, "__esModule", {
+  value: true
+});
+exports["default"] = initl;
+var _constants = require("../constants");
+var _gstime = _interopRequireDefault(require("./gstime"));
+function _interopRequireDefault(obj) { return obj && obj.__esModule ? obj : { "default": obj }; }
+/*-----------------------------------------------------------------------------
+ *
+ *                           procedure initl
+ *
+ *  this procedure initializes the sgp4 propagator. all the initialization is
+ *    consolidated here instead of having multiple loops inside other routines.
+ *
+ *  author        : david vallado                  719-573-2600   28 jun 2005
+ *
+ *  inputs        :
+ *    ecco        - eccentricity                           0.0 - 1.0
+ *    epoch       - epoch time in days from jan 0, 1950. 0 hr
+ *    inclo       - inclination of satellite
+ *    no          - mean motion of satellite
+ *    satn        - satellite number
+ *
+ *  outputs       :
+ *    ainv        - 1.0 / a
+ *    ao          - semi major axis
+ *    con41       -
+ *    con42       - 1.0 - 5.0 cos(i)
+ *    cosio       - cosine of inclination
+ *    cosio2      - cosio squared
+ *    eccsq       - eccentricity squared
+ *    method      - flag for deep space                    'd', 'n'
+ *    omeosq      - 1.0 - ecco * ecco
+ *    posq        - semi-parameter squared
+ *    rp          - radius of perigee
+ *    rteosq      - square root of (1.0 - ecco*ecco)
+ *    sinio       - sine of inclination
+ *    gsto        - gst at time of observation               rad
+ *    no          - mean motion of satellite
+ *
+ *  locals        :
+ *    ak          -
+ *    d1          -
+ *    del         -
+ *    adel        -
+ *    po          -
+ *
+ *  coupling      :
+ *    getgravconst
+ *    gstime      - find greenwich sidereal time from the julian date
+ *
+ *  references    :
+ *    hoots, roehrich, norad spacetrack report #3 1980
+ *    hoots, norad spacetrack report #6 1986
+ *    hoots, schumacher and glover 2004
+ *    vallado, crawford, hujsak, kelso  2006
+ ----------------------------------------------------------------------------*/
+function initl(options) {
+  var ecco = options.ecco,
+    epoch = options.epoch,
+    inclo = options.inclo,
+    opsmode = options.opsmode;
+  var no = options.no;
+
+  // sgp4fix use old way of finding gst
+  // ----------------------- earth constants ---------------------
+  // sgp4fix identify constants and allow alternate values
+
+  // ------------- calculate auxillary epoch quantities ----------
+  var eccsq = ecco * ecco;
+  var omeosq = 1.0 - eccsq;
+  var rteosq = Math.sqrt(omeosq);
+  var cosio = Math.cos(inclo);
+  var cosio2 = cosio * cosio;
+
+  // ------------------ un-kozai the mean motion -----------------
+  var ak = Math.pow(_constants.xke / no, _constants.x2o3);
+  var d1 = 0.75 * _constants.j2 * (3.0 * cosio2 - 1.0) / (rteosq * omeosq);
+  var delPrime = d1 / (ak * ak);
+  var adel = ak * (1.0 - delPrime * delPrime - delPrime * (1.0 / 3.0 + 134.0 * delPrime * delPrime / 81.0));
+  delPrime = d1 / (adel * adel);
+  no /= 1.0 + delPrime;
+  var ao = Math.pow(_constants.xke / no, _constants.x2o3);
+  var sinio = Math.sin(inclo);
+  var po = ao * omeosq;
+  var con42 = 1.0 - 5.0 * cosio2;
+  var con41 = -con42 - cosio2 - cosio2;
+  var ainv = 1.0 / ao;
+  var posq = po * po;
+  var rp = ao * (1.0 - ecco);
+  var method = 'n';
+
+  //  sgp4fix modern approach to finding sidereal time
+  var gsto;
+  if (opsmode === 'a') {
+    //  sgp4fix use old way of finding gst
+    //  count integer number of days from 0 jan 1970
+    var ts70 = epoch - 7305.0;
+    var ds70 = Math.floor(ts70 + 1.0e-8);
+    var tfrac = ts70 - ds70;
+
+    //  find greenwich location at epoch
+    var c1 = 1.72027916940703639e-2; // eslint-disable-line no-loss-of-precision
+    var thgr70 = 1.7321343856509374; // eslint-disable-line no-loss-of-precision
+    var fk5r = 5.07551419432269442e-15; // eslint-disable-line no-loss-of-precision
+    var c1p2p = c1 + _constants.twoPi;
+    gsto = (thgr70 + c1 * ds70 + c1p2p * tfrac + ts70 * ts70 * fk5r) % _constants.twoPi;
+    if (gsto < 0.0) {
+      gsto += _constants.twoPi;
+    }
+  } else {
+    gsto = (0, _gstime["default"])(epoch + 2433281.5);
+  }
+  return {
+    no: no,
+    method: method,
+    ainv: ainv,
+    ao: ao,
+    con41: con41,
+    con42: con42,
+    cosio: cosio,
+    cosio2: cosio2,
+    eccsq: eccsq,
+    omeosq: omeosq,
+    posq: posq,
+    rp: rp,
+    rteosq: rteosq,
+    sinio: sinio,
+    gsto: gsto
+  };
+}