Funny ADS-B positions: zig-zag

Take flight ASL334 on 16th Feb 2015 (and sort the position reports by timestamp)

echo "lat,lon,clock,type" > data.csv
cat adsb.json | \
jq -r 'select(.ident=="ASL334" and .clock >= "1424041200" and .clock < "1424127600")|[.lat,.lon,.clock,.updateType]|join(",")' | \
sort --key=3n -t, >> data.csv

click on the markers to get tracks details: spot the zig-zag at around track 60!

<!DOCTYPE html>
<html>
<head>
  <title></title>
  <script src="https://maps.google.com/maps/api/js?sensor=true"></script>
  <script src="https://cdnjs.cloudflare.com/ajax/libs/gmaps.js/0.4.12/gmaps.min.js"></script>
  <script type="text/javascript" src="https://cdnjs.cloudflare.com/ajax/libs/queue-async/1.0.7/queue.js"></script>
  <script type="text/javascript" src="https://cdnjs.cloudflare.com/ajax/libs/d3/3.5.5/d3.min.js"></script>
  <style type="text/css">
    #map {
      width: 1200px;
      height: 650px;
    }
  </style>
</head>

queue()
    .defer(dsv, "data.csv")
    .await(ready);

// this gets executed once the files have been asynchronously read
  function ready(error, tracks) {
    var path = [];
    tracks.forEach(function(d) {
      path.push([d.lat,d.lon]);
    });

map.drawPolyline({
      path: path,
      strokeColor: '#131540',
      strokeOpacity: 0.6,
      strokeWeight: 6
    });

for (var i = 0; i < path.length; i++) {
      map.addMarker({
        lat: path[i][0],
        lng: path[i][1],
        infoWindow: {
          content: '<p>track[' + i + '] @ ' + tracks[i].clock + '<br> type: ' + 
          (tracks[i].type == 'A' ? 'ADS-B' :
          tracks[i].type == 'Z' ? 'Radar' :
          tracks[i].type == 'O' ? 'Transoceanic':
          tracks[i].type == 'P' ? 'Estimated': 
          tracks[i].type == 'D' ? 'datalink':
          'unknown') + 
          '.</p>'
        }
      });
    }
  }
  </script>
</body>
</html>

Modified http://maps.google.com/maps/api/js?sensor=true to a secure url

https://maps.google.com/maps/api/js?sensor=true

https://cdnjs.cloudflare.com/ajax/libs/gmaps.js/0.4.12/gmaps.min.js

https://cdnjs.cloudflare.com/ajax/libs/queue-async/1.0.7/queue.js

https://cdnjs.cloudflare.com/ajax/libs/d3/3.5.5/d3.min.js