Getting lat/lon for a whole day.

Hey, I was trying to generate a list containing the lat/lon of the ISS in every second (preferably millisecond) of the day, I tried to do this and ended up crashing my browser, is there any efficient way to do so without crashing my browser?

function predPoints(tle1, tle2){
  var dateTime = new Date();
  var i;
  for (i = 0; i < 86401; i++){
    var satrec = satellite.twoline2satrec(tle1, tle2);

    var positionAndVelocity = satellite.propagate(satrec, dateTime.setSeconds(dateTime.getSeconds() + i ));
    var positionEci = positionAndVelocity.position;

    var gmst = satellite.gstime( dateTime.setSeconds(dateTime.getSeconds() + i ));

    var positionGd = satellite.eciToGeodetic(positionEci, gmst);

    var longitude = positionGd.longitude,
        latitude  = positionGd.latitude;

    var longitudeStr = satellite.degreesLong(longitude),
        latitudeStr  = satellite.degreesLat(latitude);

    position = [longitudeStr, latitude]
    console.log(position);
  }

[davidcalhoun]

It sounds like there’s a problem in your code that is causing an infinite loop. Double check the stop condition and make sure it is indeed exiting. I’m using a similar looping strategy with own library and it works fine and is very fast.

One second intervals will get you a pretty nice ground track, except at extreme polar latitudes on Mercator projection maps, which have more map distortion and need <1s intervals for a slightly smoother-looking line at those latitudes.

[JaniniRami]

Thank you so much, removing the vars and declaring them outside the function made it work, Also thanks for the advice I will try to use milliseconds instead of seconds and see how they compare in accuracy!