Files
wavelog/assets/js/sections/flightpath.js
Andreas Kristiansen 868d6b02fb Playing with sats
2024-05-01 08:59:22 +02:00

470 lines
12 KiB
JavaScript

var satmarker;
var icon_dot_url = base_url + "assets/icons/saticon.png";
var saticon = L.icon({ iconUrl: icon_dot_url, iconSize: [30, 30] });
var sats = (function (L, d3, satelliteJs) {
var RADIANS = Math.PI / 180;
var DEGREES = 180 / Math.PI;
var R_EARTH = 6378.137; // equatorial radius (km)
/* =============================================== */
/* =============== CLOCK ========================= */
/* =============================================== */
/**
* Factory function for keeping track of elapsed time and rates.
*/
function Clock() {
this._rate = 60; // 1ms elapsed : 60sec simulated
this._date = d3.now();
this._elapsed = 0;
};
Clock.prototype.date = function (timeInMs) {
if (!arguments.length) return this._date + (this._elapsed * this._rate);
this._date = timeInMs;
return this;
};
Clock.prototype.elapsed = function (ms) {
if (!arguments.length) return this._date - d3.now(); // calculates elapsed
this._elapsed = ms;
return this;
};
Clock.prototype.rate = function (secondsPerMsElapsed) {
if (!arguments.length) return this._rate;
this._rate = secondsPerMsElapsed;
return this;
};
/* ==================================================== */
/* =============== CONVERSION ========================= */
/* ==================================================== */
function satrecToFeature(satrec, date, props) { // DJ7NT: This is never called
var properties = props || {};
var positionAndVelocity = satelliteJs.propagate(satrec, date);
var gmst = satelliteJs.gstime(date);
var positionGd = satelliteJs.eciToGeodetic(positionAndVelocity.position, gmst);
properties.height = positionGd.height;
return {
type: "FeatureCollection",
"features": [ {
type: 'Feature',
properties: properties,
geometry: {
type: 'Point',
coordinates: [
positionGd.longitude * DEGREES,
positionGd.latitude * DEGREES
]
}
},
{
type: 'Feature',
properties: {infoText: 'blabla'},
geometry: {
type: 'Point',
coordinates: [
positionGd.longitude * DEGREES,
positionGd.latitude * DEGREES
]
}
}]
};
};
/* ==================================================== */
/* =============== TLE ================================ */
/* ==================================================== */
/**
* Factory function for working with TLE.
*/
function TLE() {
this._properties;
this._date;
};
TLE.prototype._lines = function (arry) {
return arry.slice(0, 2);
};
TLE.prototype.satrecs = function (tles) {
return tles.map(function (d) {
return satelliteJs.twoline2satrec.apply(null, this._lines(d));
});
};
TLE.prototype.features = function (tles) {
var date = this._date || d3.now();
return tles.map(function (d) {
var satrec = satelliteJs.twoline2satrec.apply(null, this._lines(d));
return satrecToFeature(satrec, date, this._properties(d));
});
};
TLE.prototype.lines = function (func) {
if (!arguments.length) return this._lines;
this._lines = func;
return this;
};
TLE.prototype.properties = function (func) {
if (!arguments.length) return this._properties;
this._properties = func;
return this;
};
TLE.prototype.date = function (ms) {
if (!arguments.length) return this._date;
this._date = ms;
return this;
};
/* ==================================================== */
/* =============== PARSE ============================== */
/* ==================================================== */
/**
* Parses text file string of tle into groups.
* @return {string[][]} Like [['tle line 1', 'tle line 2'], ...]
*/
function parseTle(tleString) {
// remove last newline so that we can properly split all the lines
var lines = tleString.replace(/\r?\n$/g, '').split(/\r?\n/);
return lines.reduce(function (acc, cur, index) {
if (index % 2 === 0) acc.push([]);
acc[acc.length - 1].push(cur);
return acc;
}, []);
};
/* ==================================================== */
/* =============== SATELLITE ========================== */
/* ==================================================== */
/**
* Satellite factory function that wraps satellitejs functionality
* and can compute footprints based on TLE and date
*
* @param {string[][]} tle two-line element
* @param {Date} date date to propagate with TLE
*/
function Satellite(tle, date) {
this._satrec = satelliteJs.twoline2satrec(tle[0], tle[1]);
this._satNum = this._satrec.satnum; // NORAD Catalog Number
this._altitude; // km
this._position = {
lat: null,
lng: null
};
this._halfAngle; // degrees
this._date;
this._gmst;
this.setDate(date);
this.update();
this._orbitType = this.orbitTypeFromAlt(this._altitude); // LEO, MEO, or GEO
};
/**
* Updates satellite position and altitude based on current TLE and date
*/
Satellite.prototype.update = function () {
try {
var positionAndVelocity = satelliteJs.propagate(this._satrec, this._date);
var positionGd = satelliteJs.eciToGeodetic(positionAndVelocity.position, this._gmst);
this._position = {
lat: positionGd.latitude * DEGREES,
lng: positionGd.longitude * DEGREES
};
this._altitude = positionGd.height;
satmarker.setLatLng(this._position);
} catch (e) {
// Malicious // non-calcable SAT Found
} finally {
return this;
}
};
/**
* @returns {GeoJSON.Polygon} GeoJSON describing the satellite's current footprint on the Earth
*/
Satellite.prototype.getFootprint = function () {
var theta = this._halfAngle * RADIANS;
coreAngle = this._coreAngle(theta, this._altitude, R_EARTH) * DEGREES;
return d3.geoCircle()
.center([this._position.lng, this._position.lat])
.radius(coreAngle)();
};
Satellite.prototype.getLocation = function () {
return d3.geoCircle()
.center([this._position.lng, this._position.lat])
.radius(1)();
};
/**
* A conical satellite with half angle casts a circle on the Earth. Find the angle
* from the center of the earth to the radius of this circle
* @param {number} theta: Satellite half angle in radians
* @param {number} altitude Satellite altitude
* @param {number} r Earth radius
* @returns {number} core angle in radians
*/
Satellite.prototype._coreAngle = function (theta, altitude, r) {
// if FOV is larger than Earth, assume it goes to the tangential point
// if (Math.sin(theta) != r / (altitude + r)) {
return Math.acos(r / (r + altitude));
// }
// return Math.abs(Math.asin((r + altitude) * Math.sin(theta) / r)) - theta;
};
Satellite.prototype.halfAngle = function (halfAngle) {
if (!arguments.length) return this._halfAngle;
this._halfAngle = halfAngle;
return this;
};
Satellite.prototype.satNum = function (satNum) {
if (!arguments.length) return this._satNum;
this._satNum = satNum;
return this;
};
Satellite.prototype.altitude = function (altitude) {
if (!arguments.length) return this._altitude;
this._altitude = altitude;
return this;
};
Satellite.prototype.position = function (position) {
if (!arguments.length) return this._position;
this._position = position;
return this;
};
Satellite.prototype.getOrbitType = function () {
return this._orbitType;
};
/**
* sets both the date and the Greenwich Mean Sidereal Time
* @param {Date} date
*/
Satellite.prototype.setDate = function (date) {
this._date = date;
this._gmst = satelliteJs.gstime(date);
return this;
};
/**
* Maps an altitude to a type of satellite
* @param {number} altitude (in KM)
* @returns {'LEO' | 'MEO' | 'GEO'}
*/
Satellite.prototype.orbitTypeFromAlt = function (altitude) {
console.log(altitude);
this._altitude = altitude || this._altitude;
return this._altitude < 1200 ? 'LEO' : this._altitude > 22000 ? 'GEO' : 'MEO';
};
/* =============================================== */
/* =============== LEAFLET MAP =================== */
/* =============================================== */
// Approximate date the tle data was aquired from https://www.space-track.org/#recent
// var TLE_DATA_DATE = new Date(2024, 04, 18).getTime();
var TLE_DATA_DATE = Date.now();
var leafletMap;
var attributionControl;
var activeClock;
var sats;
var svgLayer;
function projectPointCurry(map) {
return function (x, y) {
const point = map.latLngToLayerPoint(L.latLng(y, x));
this.stream.point(point.x, point.y);
}
};
function init() {
svgLayer = L.svg();
leafletMap = L.map('sat_map', {
zoom: 3,
center: [20, 0],
// attributionControl: false,
layers: [
L.tileLayer('http://{s}.tile.openstreetmap.org/{z}/{x}/{y}.png', {
// noWrap: false,
}),
svgLayer
]
});
// L.terminator().addTo(leafletMap);
// L.marker(["50","7"],{
// title: "blabla",
// zIndex: 1000}
// ).addTo(leafletMap);
satmarker = L.marker(
[0, 0], {
icon: saticon,
title: 'sat',
zIndex: 1000,
}
).addTo(leafletMap);
attributionControl = L.control.attribution({
prefix: ''
}).addTo(leafletMap);
var transform = d3.geoTransform({
point: projectPointCurry(leafletMap)
});
path = d3.geoPath()
.projection(transform)
.pointRadius(2.5);
};
function updateSats(date) {
sats.forEach(function (sat) {
sat.setDate(date).update();
});
return sats
};
/**
* Create satellite objects for each record in the TLEs and begin animation
* @param {string[][]} parsedTles
*/
function initSats(parsedTles) {
activeClock = new Clock()
.rate(1)
.date(TLE_DATA_DATE);
sats = parsedTles.map(function (tle) {
var sat = new Satellite(tle, new Date(2024, 4, 18));
sat.halfAngle(30);
// sat.halfAngle(sat.getOrbitType() === 'LEO' ? Math.random() * (30 - 15) + 15 : Math.random() * 4 + 1);
return sat;
});
leafletMap.on('zoom', draw);
window.requestAnimationFrame(animateSats);
return sats;
};
function invertProjection(projection) {
return function (x, y) {
const point = projection.invert([x, y]);
this.stream.point(point[0], point[1]);
};
}
function clipMercator(geoJson) {
const mercator = d3.geoMercator();
const inverseMercator = d3.geoTransform({
point: invertProjection(mercator)
});
// D3 geoProject handles Mercator clipping
const newJson = d3.geoProject(geoJson, mercator);
return d3.geoProject(newJson, inverseMercator);
}
function draw() {
var transform = d3.geoTransform({
point: projectPointCurry(leafletMap)
});
var geoPath = d3.geoPath()
.projection(transform);
d3.select(svgLayer._container)
.selectAll('.footprint')
.data(sats, function (sat) {
return sat._satNum; // DJ7NT: This is the Number of the SAT
})
.join(
function (enter) {
return enter.append('path').attr('class', function (sat) {
return 'footprint footprint--' + sat.getOrbitType();
});
},
function (update) {
return update;
},
function (exit) {
return exit.remove();
}
).attr('d', function (sat) {
// return geoPath(clipMercator(sat.getLocation())); // DJ7NT: this is the "point" of the SAT
let xx= geoPath(clipMercator(sat.getFootprint()));
return xx;
});
};
function animateSats(elapsed) {
var dateInMs = activeClock.elapsed(elapsed)
.date();
var date = new Date(dateInMs);
attributionControl.setPrefix(date);
updateSats(date);
draw();
window.requestAnimationFrame(animateSats);
}
function start(data) {
init();
initSats(parseTle(data.tle));
}
return {
start: start
};
}(window.L, window.d3, window.satellite))
function plot_sat() {
var container = L.DomUtil.get('sat_map');
if(container != null){
container._leaflet_id = null;
container.remove();
}
amap = $('#sat_map').val();
if (amap == undefined) {
$("#satcontainer").append('<div id="sat_map" class="map-leaflet" style="width: 100%; height: 85vh"></div>');
}
$.ajax({
url: base_url + 'index.php/satellite/get_tle',
type: 'post',
data: {
sat: $("#sats").val(),
},
success: function (data) {
sats.start(data);
},
error: function (data) {
alert('Something went wrong!');
},
});
}