baseStyles.css

.stroke {
  fill: none;
  stroke: #000;
  stroke-width: 3px;
}

.fill {
  fill: #fff;
}

.graticule {
  fill: none;
  stroke: #777;
  stroke-width: 0.5px;
  stroke-opacity: 0.5;
}

.land {
  fill: #222;
}

.boundary {
  fill: none;
  stroke: #fff;
  stroke-width: 0.5px;
}

p {
  font-family: Courier;
}

#description {
  
  position: absolute;
  left: 500px;
  top: 30px;
  line-height: 6px
}

baseTemplate.js

var canvas = d3.select("#map"),
    width = canvas.property("width"),
    height = canvas.property("height"),
    context = canvas.node().getContext("2d");

var center = [width/2, height/2]

var missiles = [
  {'name': 'Hwasong', 'dist': 625, 'tested': true, 'hidden': true},
  {'name': 'Nodong', 'dist': 800, 'tested': true, 'hidden': true},
  {'name': 'Musudan', 'dist': 2200, 'tested': true, 'hidden': true},
  {'name': 'KN-08', 'dist':  7200, 'tested': false, 'hidden': true}
]

missiles.forEach(function(d){
  d3.selectAll("."+ d.name).style("visibility", "hidden")
})

var updateDistance = function(distance){
  document.getElementById("distance").innerHTML = "Distance from North Korea: " + distance + " miles"
}

var zoomScale = d3.scalePow().domain([0,1]).range([height * 4,height/6]).exponent(0.5)

var projection = d3.geoAzimuthalEquidistant()
    .scale(zoomScale(0))
    .translate(center)
    .precision(0.1)
    .rotate([-127.5101, -40.339, -20]);

var path = d3.geoPath()
    .projection(projection)
    .context(context);

var distBetweenPoints = function(a,b){
  return Math.sqrt(Math.pow(a[0] - b[0], 2) + Math.pow(a[1] - b[1], 2))
}

var drawCenteredCircle = function(radius, color, lineWidth){
      context.beginPath();
          context.arc(center[0], center[1], radius, 0, 2 * Math.PI);
          context.strokeStyle = color;
          context.lineWidth = lineWidth;
          context.stroke();
          context.lineWidth = 1;
}

/*
canvas.call(d3.drag()
    .on("start", dragstarted)
    .on("drag", dragged));
    */

var render = function() {},
    v0, // Mouse position in Cartesian coordinates at start of drag gesture.
    r0, // Projection rotation as Euler angles at start.
    q0; // Projection rotation as versor at start.
/*
function dragstarted() {
  v0 = versor.cartesian(projection.invert(d3.mouse(this)));
  r0 = projection.rotate();
  q0 = versor(r0);
}

function dragged() {
  var v1 = versor.cartesian(projection.rotate(r0).invert(d3.mouse(this))),
      q1 = versor.multiply(q0, versor.delta(v0, v1)),
      r1 = versor.rotation(q1);
  projection.rotate(r1);
  console.log(r1)
  render();
}
*/
var toRadians = function(value) { return value * Math.PI / 180}
var toDegrees = function(value) { return value / Math.PI * 180}
LatLondistanceTo = function(a, b) {
    var point1 = {
      'lat': a[1],
      'lon': a[0]
    } 
    var point2 = {
      'lat': b[1],
      'lon': b[0]
    } 

    var R = 3959;
    var φ1 = toRadians(point1.lat),  λ1 = toRadians(point1.lon);
    var φ2 = toRadians(point2.lat), λ2 = toRadians(point2.lon);
    var Δφ = φ2 - φ1;
    var Δλ = λ2 - λ1;

    var a = Math.sin(Δφ/2) * Math.sin(Δφ/2)
          + Math.cos(φ1) * Math.cos(φ2)
          * Math.sin(Δλ/2) * Math.sin(Δλ/2);
    var c = 2 * Math.atan2(Math.sqrt(a), Math.sqrt(1-a));
    var d = R * c;

    return d;
};

LatLonGetPoint = function(distance, bearing, point) {
    radius = 3959;

    var δ = Number(distance) / radius; // angular distance in radians
    var θ = toRadians(Number(bearing));


    var φ1 = toRadians(point.lat);
    var λ1 = toRadians(point.lon);

    var sinφ1 = Math.sin(φ1), cosφ1 = Math.cos(φ1);
    var sinδ = Math.sin(δ), cosδ = Math.cos(δ);
    var sinθ = Math.sin(θ), cosθ = Math.cos(θ);

    var sinφ2 = sinφ1*cosδ + cosφ1*sinδ*cosθ;
    var φ2 = Math.asin(sinφ2);
    var y = sinθ * sinδ * cosφ1;
    var x = cosδ - sinφ1 * sinφ2;
    var λ2 = λ1 + Math.atan2(y, x);

    return {'lat': toDegrees(φ2), 'lon': (toDegrees(λ2)+540)%360-180}; // normalise to −180..+180°
};

d3.json("https://unpkg.com/world-atlas@1/world/110m.json", function(error, world) {
  if (error) throw error;
  var nk = world.objects.countries.geometries.filter(function(d){return d.id == "408"})

  var sphere = {type: "Sphere"},
      land = topojson.feature(world, world.objects.land),
      nktopo = topojson.feature(world, world.objects.countries);


  var previous = 0;
  var now = 0;

  var updateBasedOnDistance = function(visibleDistance){
    missiles.forEach(function(d){
      if(visibleDistance > d.dist & d.hidden){
        d.hidden = false;
        d3.selectAll("." + d.name).style("visibility", "visible")
      }
      if(!d.hidden){
        var point = LatLonGetPoint(d.dist, 0, {'lon': 127.51, 'lat': 40.3399});
        drawCenteredCircle(distBetweenPoints(projection([point.lon, point.lat]), center), "#ffa296", 1)
      }
    })
    
    drawCenteredCircle(center[0]* 1.2, "white", 120)

    // update miles count
    updateDistance(Math.round(visibleDistance /10)*10);

  }


  canvas.on("mousemove",function(){

    var xy = d3.mouse(this);
    console.log(projection.invert(xy))
    console.log(LatLondistanceTo(projection.invert(xy), [127.51, 40.3399]))

  })


  render = function(stage) {
    // update scale
    projection.scale(zoomScale(stage))

    // redraw world with new scale

    context.clearRect(0, 0, width, height);
    context.beginPath(), path(sphere), context.fillStyle = "#fff", context.fill();
    context.beginPath(), path(nktopo), context.fillStyle = "#555", context.fill(), context.strokeStyle = "#eee", context.stroke();
    context.beginPath(), path(sphere), context.stroke();

    // calculate visible distance in image, and update accordingly
    updateBasedOnDistance(LatLondistanceTo(projection.invert([width,center[1]]), [127.51, 40.3399]))

  };

  var stage = 0;
  render(stage)
  var t = d3.timer(function(elapsed) {

    if (elapsed / 300 > stage) {
      stage += .002;
      
      render(stage)

      }

    if(stage > 1){
      t.stop();
    }
  }, 500);

});

index.html

<!DOCTYPE html>
<meta charset="utf-8">
<link rel="stylesheet" href="baseStyles.css">
<body>

<div><canvas id="map" width="500" height="500" style="position: absolute; left: 0; top: 0; z-index: 0;">
<canvas id="layerAnnotations" width="500" height="500" style="position: absolute; left: 0; top: 0; z-index: 1;"></cavnas>
</div>
<div id="description"><p id="distance">Distance from North Korea: 300 miles</p>
<p>..............................................</p>
<p class="Hwasong">Scud Missile: ~625 miles reach</p>
<p class = "Hwasong"></p>
<p class="Nodong">Nodong Missile: ~800 miles reach</p>
<p class = "Nodong"></p>
<p class="Musudan">Musudan Missile: ~2200 miles reach</p>
<p class = "Musudan"></p>
<p class="KN-08">KN-08 Missile: ~7200 miles reach (in progress)</p>
<p class = "KN-08"></p></div>
<p style="position: absolute; left: 500px; top: 400px; z-index: 1;"><a href="http://www.nti.org/learn/countries/north-korea/">Source: Nuclear Threat Initiative</p>
</body>
<script src="https://d3js.org/d3.v4.min.js"></script>
<script src="https://unpkg.com/topojson-client@2"></script>
<script src="baseTemplate.js"></script>