https://github.com/nsat/jspredict

A Javascript port of the popular predict satellite tracking library
https://github.com/nsat/jspredict

Last synced: 2 months ago
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A Javascript port of the popular predict satellite tracking library

• Host: GitHub
• URL: https://github.com/nsat/jspredict
• Owner: nsat
• License: other
• Created: 2015-11-03T01:32:42.000Z (over 8 years ago)
• Default Branch: master
• Last Pushed: 2021-10-15T21:59:54.000Z (over 2 years ago)
• Last Synced: 2024-03-22T21:53:32.306Z (3 months ago)
• Language: JavaScript
• Homepage:
• Size: 50.8 KB
• Stars: 48
• Watchers: 15
• Forks: 15
• Open Issues: 4
• Metadata Files:
  • Readme: README.md
  • License: LICENSE

Lists

• awesome-space - jspredict - A Javascript port of the popular predict satellite tracking library. (Spacecraft / Tracking & Orbit Determination)

README

        
# JsPredict

A Javascript port of the popular `predict` satellite tracking library.

### Based on:

- PREDICT: http://www.qsl.net/kd2bd/predict.html

- PyPredict: https://github.com/nsat/pypredict

- Python-SGP4: https://github.com/brandon-rhodes/python-sgp4

### Depends on:

- Satellite.js: https://github.com/shashwatak/satellite-js

- Moment.js: https://github.com/moment/moment

## Installation

JsPredict has been pushed to the `NPM`, `Meteor` (Atmosphere), and `Bower` package registries, and can also be used by including the src file directly.

### NPM

```

npm install jspredict

```

### Meteor

```

meteor add rosh93:jspredict

```

### Bower

```

bower install jspredict

```

### Manual Include

Download and include `moment.js`: http://momentjs.com/

Include both `satellite.js` and `jspredict.js` to get `satellite` and `jspredict` available on the global `window` namespace.

## API

#### Input Types

```js

tle = 3 line string with "\n" character line breaks

qth = 3 element array [latitude (degrees), longitude (degrees), altitude (km)]

time, start, or end = unix timestamp (ms) or date object "new Date()"

```

#### Methods

```js

observe(tle 'required', qth 'optional', time 'optional')

observes(tle 'required', qth 'optional', start 'optional', end 'required', interval 'optional')

transits(tle 'required', qth 'required', start 'optional', end 'required', minElevation 'optional', maxTransits 'optional')

```

## Examples

### Observe a Satellite:

```js

> var tle = '0 LEMUR-2 JEROEN\n1 40934U 15052E   15306.10048119  .00001740  00000-0  15647-3 0  9990\n2 40934   6.0033 141.2190 0010344 133.6141 226.4604 14.76056230  5130';

> var jspredict = require('jspredict');

> jspredict.observe(tle, null);

{ eci:

   { position:

      { x: 6780.217861682045,

        y: -1754.945569075624,

        z: -382.1001487529574 },

     velocity:

      { x: 1.8548312182745958,

        y: 7.28225574805238,

        z: -0.6742937006920255 } },

  gmst: 1.2743405900207918,

  latitude: -3.141891992384467,

  longitude: -87.52591692501754,

  altitude: 635.9975103859342,

  footprint: 5474.178485006438 }

```

### Observe a Satellite from an Observer at 15 lat, 130, lon, 10m alt:

```js

> var tle = '0 LEMUR-2 JEROEN\n1 40934U 15052E   15306.10048119  .00001740  00000-0  15647-3 0  9990\n2 40934   6.0033 141.2190 0010344 133.6141 226.4604 14.76056230  5130';

> var qth = [15, 130, .1];

> jspredict.observe(tle, qth);

{ eci:

   { position:

      { x: 6808.890168241923,

        y: -1638.1745052042197,

        z: -392.83171494347425 },

     velocity:

      { x: 1.729088700801128,

        y: 7.313653076194647,

        z: -0.6671038712037236 } },

  gmst: 1.275507328110315,

  latitude: -3.2301661539920232,

  longitude: -86.6090669346031,

  altitude: 636.124394452163,

  footprint: 5474.682764305541,

  azimuth: 75.42118188269167,

  elevation: -70.0809770796008,

  rangeSat: 12666.306550391646,

  doppler: 1.0000075435881037 }

```

### Get Transits for Satellite and Observer (minimum elevation of 2 degrees; obtain a maximum of 4 transits)

```js

> var tle = '0 LEMUR-2 JEROEN\n1 40934U 15052E   15306.10048119  .00001740  00000-0  15647-3 0  9990\n2 40934   6.0033 141.2190 0010344 133.6141 226.4604 14.76056230  5130';

> var qth = [15, 130, .1];

> jspredict.transits(tle, qth, 1446516345242, 1446545135046, 2, 4);

[ { start: 1446519623929.2715,

    end: 1446520436786.1265,

    maxElevation: 26.592307317708126,

    apexAzimuth: 173.44894443969358,

    maxAzimuth: 244.2708297009277,

    minAzimuth: 108.07476128814045,

    duration: 812856.8549804688 },

  { start: 1446525901933.6611,

    end: 1446526693580.5254,

    maxElevation: 24.777958881102588,

    apexAzimuth: 170.71484739848532,

    maxAzimuth: 244.97838417889344,

    minAzimuth: 110.85020906380568,

    duration: 791646.8642578125 },

  { start: 1446532176864.1306,

    end: 1446533027054.9875,

    maxElevation: 20.48579856021555,

    apexAzimuth: 194.49205827738396,

    maxAzimuth: 242.43145831257118,

    minAzimuth: 114.97146874644389,

    duration: 850190.8569335938 },

  { start: 1446538461828.8735,

    end: 1446539183964.2942,

    maxElevation: 15.359176537330036,

    apexAzimuth: 188.34763284223402,

    maxAzimuth: 236.24036969182643,

    minAzimuth: 123.49296057832372,

    duration: 722135.4206542969 } ]

>

```