Version 5.0.0.

.gitignore

@@ -6,3 +6,4 @@ lib
 sgp4_verification/lib/sgp4
 *.log
 package-lock.json
+test/propagation/sgp4prop

CHANGELOG.md

@@ -1,5 +1,10 @@
 # Changelog
 
+## 5.0.0 (2023-01-06)
+
+- Errors in calculations are fixed, WGS72 is used instead of WGS84 (#107).
+- Dependencies are upgraded.
+
 ## 4.1.4 (2022-07-18)
 
 - TypeScript definition for `ecfToEci` function is added. 

package.json

@@ -1,6 +1,6 @@
 {
   "name": "satellite.js",
-  "version": "4.1.4",
+  "version": "5.0.0",
   "description": "SGP4/SDP4 calculation library",
   "main": "lib/index.js",
   "jsnext:main": "dist/satellite.es.js",
@@ -10,8 +10,8 @@
     "build": "rimraf lib dist && npm run transpile && npm run dist",
     "transpile": "babel src --out-dir lib --ignore indexUmd.js && node --require @babel/register commands/add-copyright.js 'lib/**/*.js'",
     "dist": "npm run dist:es && npm run dist:umd:dev && npm run dist:umd:prod",
-    "dist:es": "rollup --config rollup.config.es.js && node --require @babel/register commands/add-copyright.js 'dist/satellite.es.js'",
-    "dist:umd": "rollup --config rollup.config.js",
+    "dist:es": "rollup --bundleConfigAsCjs --config rollup.config.es.js && node --require @babel/register commands/add-copyright.js 'dist/satellite.es.js'",
+    "dist:umd": "rollup --bundleConfigAsCjs --config rollup.config.js",
     "dist:umd:dev": "cross-env NODE_ENV=development npm run dist:umd && node --require @babel/register commands/add-copyright.js 'dist/**/satellite.js'",
     "dist:umd:prod": "cross-env NODE_ENV=production npm run dist:umd && node --require @babel/register commands/add-copyright.js 'dist/**/satellite.min.js'",
     "watch:es": "node --require @babel/register rollup.watch.es.js",
@@ -42,29 +42,35 @@
   },
   "dependencies": {},
   "devDependencies": {
-    "@babel/cli": "^7.11.6",
-    "@babel/core": "^7.11.6",
-    "@babel/plugin-proposal-class-properties": "^7.10.4",
-    "@babel/plugin-proposal-json-strings": "^7.10.4",
+    "@babel/cli": "^7.20.7",
+    "@babel/core": "^7.20.12",
+    "@babel/plugin-proposal-class-properties": "^7.18.6",
+    "@babel/plugin-proposal-json-strings": "^7.18.6",
     "@babel/plugin-syntax-dynamic-import": "^7.8.3",
     "@babel/plugin-syntax-import-meta": "^7.10.4",
-    "@babel/preset-env": "^7.11.5",
-    "@babel/register": "^7.11.5",
-    "@rollup/plugin-babel": "^5.2.1",
-    "chokidar": "^3.4.2",
-    "copyfiles": "^2.3.0",
-    "coveralls": "^3.1.0",
-    "cross-env": "^7.0.2",
-    "eslint": "^7.9.0",
-    "eslint-config-airbnb-base": "^14.2.0",
-    "eslint-plugin-import": "^2.22.0",
-    "glob": "^7.1.6",
-    "jest": "^26.4.2",
-    "prepend-file": "^2.0.0",
-    "raise-version": "^0.4.0",
+    "@babel/preset-env": "^7.20.2",
+    "@babel/register": "^7.18.9",
+    "@rollup/plugin-babel": "^6.0.3",
+    "@rollup/plugin-terser": "^0.2.1",
+    "chokidar": "^3.5.3",
+    "copyfiles": "^2.4.1",
+    "coveralls": "^3.1.1",
+    "cross-env": "^7.0.3",
+    "eslint": "^8.31.0",
+    "eslint-config-airbnb-base": "^15.0.0",
+    "eslint-plugin-import": "^2.26.0",
+    "glob": "^8.0.3",
+    "jest": "^29.3.1",
+    "prepend-file": "^2.0.1",
+    "raise-version": "^0.5.0",
     "rimraf": "^3.0.2",
-    "rollup": "^2.26.11",
-    "rollup-plugin-terser": "^7.0.2"
+    "rollup": "^3.9.1"
+  },
+  "jest": {
+    "testPathIgnorePatterns": [
+      "node_modules",
+      "test/propagation/sgp4prop"
+    ]
   },
   "homepage": "https://github.com/shashwatak/satellite-js",
   "directories": {

rollup.config.js

@@ -1,5 +1,5 @@
 import babel from '@rollup/plugin-babel';
-import { terser } from 'rollup-plugin-terser';
+import terser from '@rollup/plugin-terser';
 
 const { NODE_ENV } = process.env;
 

src/constants.js

@@ -3,13 +3,13 @@ export const twoPi = pi * 2;
 export const deg2rad = pi / 180.0;
 export const rad2deg = 180 / pi;
 export const minutesPerDay = 1440.0;
-export const mu = 398600.5; // in km3 / s2
-export const earthRadius = 6378.137; // in km
+export const mu = 398600.8; // in km3 / s2
+export const earthRadius = 6378.135; // in km
 export const xke = 60.0 / Math.sqrt((earthRadius * earthRadius * earthRadius) / mu);
 export const vkmpersec = (earthRadius * xke) / 60.0;
 export const tumin = 1.0 / xke;
-export const j2 = 0.00108262998905;
-export const j3 = -0.00000253215306;
-export const j4 = -0.00000161098761;
+export const j2 = 0.001082616;
+export const j3 = -0.00000253881;
+export const j4 = -0.00000165597;
 export const j3oj2 = j3 / j2;
 export const x2o3 = 2.0 / 3.0;

src/io.js

@@ -1,13 +1,6 @@
-import {
-  pi,
-  tumin,
-  deg2rad,
-} from './constants';
+import { pi, deg2rad } from './constants';
 
-import {
-  jday,
-  days2mdhms,
-} from './ext';
+import { jday, days2mdhms } from './ext';
 
 import sgp4init from './propagation/sgp4init';
 
@@ -80,13 +73,16 @@ export default function twoline2satrec(longstr1, longstr2) {
   satrec.epochdays = parseFloat(longstr1.substring(20, 32));
   satrec.ndot = parseFloat(longstr1.substring(33, 43));
   satrec.nddot = parseFloat(
-    `.${parseInt(longstr1.substring(44, 50), 10)
-    }E${longstr1.substring(50, 52)}`,
+    `.${parseInt(longstr1.substring(44, 50), 10)}E${longstr1.substring(
+      50,
+      52,
+    )}`,
   );
   satrec.bstar = parseFloat(
-    `${longstr1.substring(53, 54)
-    }.${parseInt(longstr1.substring(54, 59), 10)
-    }E${longstr1.substring(59, 61)}`,
+    `${longstr1.substring(53, 54)}.${parseInt(
+      longstr1.substring(54, 59),
+      10,
+    )}E${longstr1.substring(59, 61)}`,
   );
 
   // satrec.satnum = longstr2.substring(2, 7);
@@ -103,19 +99,15 @@ export default function twoline2satrec(longstr1, longstr2) {
   // satrec.bstar= satrec.bstar * Math.pow(10.0, ibexp);
 
   // ---- convert to sgp4 units ----
-  satrec.a = ((satrec.no * tumin) ** (-2.0 / 3.0));
-  satrec.ndot /= (xpdotp * 1440.0); // ? * minperday
-  satrec.nddot /= (xpdotp * 1440.0 * 1440);
+  // satrec.ndot /= (xpdotp * 1440.0); // ? * minperday
+  // satrec.nddot /= (xpdotp * 1440.0 * 1440);
 
   // ---- find standard orbital elements ----
   satrec.inclo *= deg2rad;
   satrec.nodeo *= deg2rad;
   satrec.argpo *= deg2rad;
   satrec.mo *= deg2rad;
 
-  satrec.alta = (satrec.a * (1.0 + satrec.ecco)) - 1.0;
-  satrec.altp = (satrec.a * (1.0 - satrec.ecco)) - 1.0;
-
   // ----------------------------------------------------------------
   // find sgp4epoch time of element set
   // remember that sgp4 uses units of days from 0 jan 1950 (sgp4epoch)
@@ -134,11 +126,7 @@ export default function twoline2satrec(longstr1, longstr2) {
   const mdhmsResult = days2mdhms(year, satrec.epochdays);
 
   const {
-    mon,
-    day,
-    hr,
-    minute,
-    sec,
+    mon, day, hr, minute, sec,
   } = mdhmsResult;
   satrec.jdsatepoch = jday(year, mon, day, hr, minute, sec);
 

src/propagation/dsinit.js

@@ -201,6 +201,7 @@ export default function dsinit(options) {
   const root22 = 1.7891679e-6;
   const root44 = 7.3636953e-9;
   const root54 = 2.1765803e-9;
+  // eslint-disable-next-line no-loss-of-precision
   const rptim = 4.37526908801129966e-3; // equates to 7.29211514668855e-5 rad/sec
   const root32 = 3.7393792e-7;
   const root52 = 1.1428639e-7;

src/propagation/dspace.js

@@ -123,6 +123,7 @@ export default function dspace(options) {
   const g44 = 1.8014998;
   const g52 = 1.0508330;
   const g54 = 4.4108898;
+  // eslint-disable-next-line no-loss-of-precision
   const rptim = 4.37526908801129966e-3; // equates to 7.29211514668855e-5 rad/sec
   const stepp = 720.0;
   const stepn = -720.0;
@@ -215,10 +216,10 @@ export default function dspace(options) {
           + (d3222 * Math.cos((-xomi + xli) - g32))
           + (d5220 * Math.cos((xomi + xli) - g52))
           + (d5232 * Math.cos((-xomi + xli) - g52))
-          + (2.0 * d4410 * Math.cos((x2omi + x2li) - g44))
+          + 2.0 * ((d4410 * Math.cos((x2omi + x2li) - g44))
           + (d4422 * Math.cos(x2li - g44))
           + (d5421 * Math.cos((xomi + x2li) - g54))
-          + (d5433 * Math.cos((-xomi + x2li) - g54));
+          + (d5433 * Math.cos((-xomi + x2li) - g54)));
         xnddt *= xldot;
       }
 

src/propagation/initl.js

@@ -109,9 +109,9 @@ export default function initl(options) {
     const tfrac = ts70 - ds70;
 
     //  find greenwich location at epoch
-    const c1 = 1.72027916940703639e-2;
-    const thgr70 = 1.7321343856509374;
-    const fk5r = 5.07551419432269442e-15;
+    const c1 = 1.72027916940703639e-2; // eslint-disable-line no-loss-of-precision
+    const thgr70 = 1.7321343856509374; // eslint-disable-line no-loss-of-precision
+    const fk5r = 5.07551419432269442e-15; // eslint-disable-line no-loss-of-precision
     const c1p2p = c1 + twoPi;
     gsto = (thgr70 + (c1 * ds70) + (c1p2p * tfrac) + (ts70 * ts70 * fk5r)) % twoPi;
     if (gsto < 0.0) {

src/propagation/sgp4init.js

@@ -5,6 +5,7 @@ import {
   j4,
   j3oj2,
   x2o3,
+  tumin,
 } from '../constants';
 
 import dpper from './dpper';
@@ -262,6 +263,9 @@ export default function sgp4init(satrec, options) {
   satrec.no = initlResult.no;
   satrec.con41 = initlResult.con41;
   satrec.gsto = initlResult.gsto;
+  satrec.a = (satrec.no * tumin) ** (-2.0 / 3.0);
+  satrec.alta = satrec.a * (1.0 + satrec.ecco) - 1.0;
+  satrec.altp = satrec.a * (1.0 - satrec.ecco) - 1.0;
   satrec.error = 0;
 
   // sgp4fix remove this check as it is unnecessary