Add gpredict.js for showing satellites orbits

bower.json

@@ -14,7 +14,8 @@
         "moment": "2.10.6",
         "bootstrap-daterangepicker": "2.1.x",
         "mapbox.js": "2.2.x",
-        "dnt-helper": "schalkneethling/dnt-helper"
+        "dnt-helper": "schalkneethling/dnt-helper",
+        "gpredict.js": "kerel-fs/gpredict.js"
     },
     "overrides": {
         "jquery": {
@@ -56,6 +57,9 @@
         },
         "dnt-helper": {
             "main": "js/dnt-helper.js"
+        },
+        "gpredict.js": {
+            "main": "dist/gpredict.min.js"
         }
     }
 }

db/base/views.py

@@ -69,6 +69,9 @@ def satellite_position(request, sat_id):
         now = datetime.now().strftime('%Y-%m-%d %H:%M:%S')
         satellite.compute(now)
         data = {
+            'name': str(sat.name),
+            'tle1': str(sat.tle1),
+            'tle2': str(sat.tle2),
             'lon': '{0}'.format(satellite.sublong),
             'lat': '{0}'.format(satellite.sublat)
         }

db/static/js/map.js

@@ -1,4 +1,4 @@
-/*global L */
+/*global L Sat_t gtk_sat_data_read_sat predict_calc julian_date Geodetic_t radians xkmper de2ra asin sin cos arccos degrees pio2 pi fabs */
 
 $(document).ready(function() {
     'use strict';
@@ -9,6 +9,13 @@ $(document).ready(function() {
 
     L.mapbox.accessToken = mapboxtoken;
     L.mapbox.config.FORCE_HTTPS = true;
+
+    // Number of positions to compute
+    var COUNT = 300;
+
+    // Interval in ms between positions to compute
+    var STEP = 60*1000;
+
     var map = L.mapbox.map('map', mapboxid, {
         zoomControl: false
     });
@@ -19,31 +26,140 @@ $(document).ready(function() {
         iconAnchor: [16, 16]
     });
 
-    var marker = L.marker([0, 0], {
+    // Create satellite marker
+    var satMarker = L.marker([0, 0], {
         icon: satIcon,
         clickable: false
     });
 
-    marker.addTo(map);
+    // Create satellite footprint
+    var satFootprint = L.polygon(
+        [],
+        {
+            stroke: true,
+            weight: 2,
+            fill: true,
+        }
+    );
 
-    function update_map(lat, lon) {
-        map.setView([lat, lon], 3);
+    // Create satellite orbit
+    var current_orbit = [];
+    var all_orbits = [];
 
-        marker.setLatLng(L.latLng(lat, lon));
+    var satOrbit = L.multiPolyline(
+        all_orbits,
+        {
+            weight: 4
+        }
+    );
+
+    var sat = new Sat_t();
+
+    satMarker.addTo(map);
+    satFootprint.addTo(map);
+    satOrbit.addTo(map);
+
+    function initialize_map(name, tle1, tle2) {
+        // Load satellite orbit data from TLE
+        gtk_sat_data_read_sat([name, tle1, tle2], sat);
+
+        {
+            var t = new Date();
+
+            var previous = 0;
+            for ( var i = 0; i < COUNT; i++) {
+                predict_calc(sat, (0,0), julian_date(t));
+                if (Math.abs(sat.ssplon - previous) > 180) {
+                    // orbit crossing -PI, PI
+                    all_orbits.push(current_orbit);
+                    current_orbit = [];
+                }
+                current_orbit.push([sat.ssplat, sat.ssplon]);
+                previous = sat.ssplon;
+                // Increase time for next point
+                t.setTime(t.getTime() + STEP);
+            }
+
+            satOrbit.setLatLngs(all_orbits);
+        }
+        update_map();
     }
 
-    (function worker() {
+    function update_map() {
+        // Recalculate satellite location
+        var t = new Date();
+        predict_calc(sat, (0, 0), julian_date(t));
+
+        // Update location on map
+        map.setView([sat.ssplat, sat.ssplon], 3);
+        satMarker.setLatLng(L.latLng(sat.ssplat, sat.ssplon));
+
+        // Refresh satellite footprint
+        {
+            var azi;
+            // var msx, msy, ssx, ssy;
+            var ssplat,
+                ssplon,
+                beta,
+                azimuth,
+                num,
+                dem;
+            // var rangelon, rangelat, mlon;
+
+            var geo = new Geodetic_t();
+
+            /* Range circle calculations.
+             * Borrowed from gsat 0.9.0 by Xavier Crehueras, EB3CZS
+             * who borrowed from John Magliacane, KD2BD.
+             * Optimized by Alexandru Csete and William J Beksi.
+             */
+            ssplat = radians(sat.ssplat);
+            ssplon = radians(sat.ssplon);
+            beta = (0.5 * sat.footprint) / xkmper;
+
+            var points = [];
+
+            for (azi = 0; azi < 360; azi += 5) {
+                azimuth = de2ra * azi;
+                geo.lat = asin(sin(ssplat) * cos(beta) + cos(azimuth) * sin(beta)
+                        * cos(ssplat));
+                num = cos(beta) - (sin(ssplat) * sin(geo.lat));
+                dem = cos(ssplat) * cos(geo.lat);
+
+                if (azi == 0 && (beta > pio2 - ssplat)) {
+                    geo.lon = ssplon + pi;
+                }
+                else if (azi == 180 && (beta > pio2 + ssplat)) {
+                    geo.lon = ssplon + pi;
+                }
+                else if (fabs(num / dem) > 1.0) {
+                    geo.lon = ssplon;
+                } else {
+                    if ((180 - azi) >= 0) {
+                        geo.lon = ssplon - arccos(num, dem);
+                    } else {
+                        geo.lon = ssplon + arccos(num, dem);
+                    }
+                }
+
+                points.push([degrees(geo.lat), degrees(geo.lon)]);
+            }
+
+            satFootprint.setLatLngs(points);
+        }
+
+    }
+
+    (function init_worker() {
         $.ajax({
             url: url,
             success: function(data) {
-                if (('lat' in data) && ('lon' in data)) {
-                    update_map(data.lat, data.lon);
+                if (('name' in data) && ('tle1' in data) && ('tle2' in data)) {
+                    initialize_map(data.name, data.tle1, data.tle2);
+                    setInterval(update_map, 5000);
                 } else {
                     $('div#map').hide();
                 }
-            },
-            complete: function() {
-                setTimeout(worker, 5000);
             }
         });
     })();

db/templates/base/satellite.html

@@ -431,5 +431,6 @@
   <script src="{% static 'lib/bootstrap-daterangepicker/daterangepicker.js' %}"></script>
   <script src="{% static 'lib/mapbox.js/mapbox.js' %}"></script>
   <script src="{% static 'js/app.backbone.js' %}"></script>
+  <script src="{% static 'lib/gpredict.js/dist/gpredict.min.js' %}"></script>
   <script src="{% static 'js/map.js' %}"></script>
 {% endblock %}