Calculate Distance in Meters When You Know Longitude and Latitude in Java

Calculate distance in meters when you know longitude and latitude in java

Based on another question on stackoverflow, I got this code.. This calculates the result in meters, not in miles :)

 public static float distFrom(float lat1, float lng1, float lat2, float lng2) {
    double earthRadius = 6371000; //meters
    double dLat = Math.toRadians(lat2-lat1);
    double dLng = Math.toRadians(lng2-lng1);
    double a = Math.sin(dLat/2) * Math.sin(dLat/2) +
               Math.cos(Math.toRadians(lat1)) * Math.cos(Math.toRadians(lat2)) *
               Math.sin(dLng/2) * Math.sin(dLng/2);
    double c = 2 * Math.atan2(Math.sqrt(a), Math.sqrt(1-a));
    float dist = (float) (earthRadius * c);

    return dist;
    }

Calculating distance between two points, using latitude longitude?

The Java code given by Dommer above gives slightly incorrect results but the small errors add up if you are processing say a GPS track. Here is an implementation of the Haversine method in Java which also takes into account height differences between two points.

/**
 * Calculate distance between two points in latitude and longitude taking
 * into account height difference. If you are not interested in height
 * difference pass 0.0. Uses Haversine method as its base.
 * 
 * lat1, lon1 Start point lat2, lon2 End point el1 Start altitude in meters
 * el2 End altitude in meters
 * @returns Distance in Meters
 */
public static double distance(double lat1, double lat2, double lon1,
        double lon2, double el1, double el2) {

    final int R = 6371; // Radius of the earth

    double latDistance = Math.toRadians(lat2 - lat1);
    double lonDistance = Math.toRadians(lon2 - lon1);
    double a = Math.sin(latDistance / 2) * Math.sin(latDistance / 2)
            + Math.cos(Math.toRadians(lat1)) * Math.cos(Math.toRadians(lat2))
            * Math.sin(lonDistance / 2) * Math.sin(lonDistance / 2);
    double c = 2 * Math.atan2(Math.sqrt(a), Math.sqrt(1 - a));
    double distance = R * c * 1000; // convert to meters

    double height = el1 - el2;

    distance = Math.pow(distance, 2) + Math.pow(height, 2);

    return Math.sqrt(distance);
}

How to calculate distance between two locations using their longitude and latitude value

Here getting distance in miles (mi)

private double distance(double lat1, double lon1, double lat2, double lon2) {
    double theta = lon1 - lon2;
    double dist = Math.sin(deg2rad(lat1)) 
                    * Math.sin(deg2rad(lat2))
                    + Math.cos(deg2rad(lat1))
                    * Math.cos(deg2rad(lat2))
                    * Math.cos(deg2rad(theta));
    dist = Math.acos(dist);
    dist = rad2deg(dist);
    dist = dist * 60 * 1.1515;
    return (dist);
}

private double deg2rad(double deg) {
    return (deg * Math.PI / 180.0);
}

private double rad2deg(double rad) {
    return (rad * 180.0 / Math.PI);
}

Java: Calculate distance between a large number of locations and performance

this is O(n)
Dont worry about performance. unless every single calculation takes too long (which it isnt).

In java, how can i calculate distance between multiple latitude and longitude?

It is not exact, and Dutch, but I don't think it is hard to understand:

package nl.abz.testjaap;

public class Locatie {
  private static final double DOORSNEDE_AARDE = 40000.0;
  public final double latitude;
  public final double longitude;

  public Locatie(double latitude, double longitude) throws IllegalArgumentException {
  if (latitude > 90 || latitude < -90) {
      throw new IllegalArgumentException("latitude moet tussen - 90 en 90 liggen, was "
              + latitude);
  }
  if (longitude < -360 || longitude > 360) {
      throw new IllegalArgumentException("Longitude moet tussen -360 en 360 liggen was "
              + longitude);
  }
  this.latitude = latitude;
  this.longitude = longitude;

}

/**
 * Calculate the distance in KM
 * 
 * @param l2
 * @return
 */
public double afstandTot(Locatie l2) {
  double lon1 = longitude / 180 * Math.PI;
  double lon2 = l2.longitude / 180 * Math.PI;
  double lat1 = latitude / 180 * Math.PI;
  double lat2 = l2.latitude / 180 * Math.PI;
  double x1 = Math.cos(lon1) * Math.cos(lat1);
  double y1 = Math.sin(lon1) * Math.cos(lat1);
  double z1 = Math.sin(lat1);

  double x2 = Math.cos(lon2) * Math.cos(lat2);
  double y2 = Math.sin(lon2) * Math.cos(lat2);
  double z2 = Math.sin(lat2);

  double psi = Math.acos(x1 * x2 + y1 * y2 + z1 * z2);
  double afstand = DOORSNEDE_AARDE / (2 * Math.PI) * psi;
  return afstand;

}

}

Calculating distance using latitude longitude coordinates in kilometers with Java

You only need to change the last line to:

return new Double((Math.toDegrees(Math.acos(theDistance))) * 
    69.09*1.6093).intValue();

1 mile = 1.6093 kilometer

How to advance X distance (meters) between two points of latitude and longitude?

So you know latA, lngA, latB, lngB. From your question, I assume that you know the speed, it's constant, v = 3 m/s. You can get the start time LocalDateTime tA = LocalDateTime.now(); You want to know your coordinates at some moment of time tX.

In order to do this, I would introduce coefLat and coefLng coefficients for transforming coordinates into meters and back. They use mean radius of Earth and translate degrees into radians:

double coefLat = 180 / Math.PI / 6371000;
double coefLng = coefLat / Math.cos(Math.PI * (latA + latB) / 360);

Then calculate distances by Lat and Lng axis and full distance in meters:

double distLat = (latB - latA) / coefLat;
double distLng = (lngB - lngA) / coefLng;
double dist = Math.sqrt(distLat * distLat + distLng * distLng);

double fullTime = dist / v; // Full time needed to pass from A to B in seconds

After some time of moving, find duration and get current coordinates:

LocalDateTime tX = LocalDateTime.now(); // get current time
long dT = Duration.between(tA, tX).getSeconds(); // in seconds
double ratio = dT / fullTime;

double latX = latA + coefLat * ratio * distLat;
double lngX = lngA + coefLng * ratio * distLng;

Please also see this answer

The full code:

public class GetCurrentCoords {

    public static void main(String[] args) {

        LocalDateTime tA = LocalDateTime.now();
        double latA = 51.504870000000004;
        double lngA = -0.21533000000000002;
        double latB = 51.50475;
        double lngB = -0.21571;

        double coefLat = 180 / Math.PI / 6371000;
        double coefLng = coefLat / Math.cos(Math.PI * (latA + latB) / 360);

        double distLat = (latB - latA) / coefLat; // meters
        double distLng = (lngB - lngA) / coefLng; // meters

        double dist = Math.sqrt(distLat * distLat + distLng * distLng);
        System.out.println("distLat = " + distLat + "m; distLng = " + distLng + "m; full dist from A to B = " + dist + "m");
        double v = 3;

        double fullTime = dist / v; // seconds
        System.out.println("full time from A to B = " + fullTime + "s");

        // let's move for 4 seconds
        try {
            TimeUnit.SECONDS.sleep(4);
        } catch (InterruptedException ex) {
            Logger.getLogger(GetCurrentCoords.class.getName()).log(Level.SEVERE, null, ex);
        }

        LocalDateTime tX = LocalDateTime.now(); 
        long dT = Duration.between(tA, tX).getSeconds();
        double ratio = dT / fullTime;

        double latX = latA + coefLat * ratio * distLat;
        double lngX = lngA + coefLng * ratio * distLng;

        System.out.println("Moving " + dT + " seconds; latX = " + latX + "; lngX = " + lngX);
     }
}

Calculating new longitude, latitude from old + n meters

The number of kilometers per degree of longitude is approximately

(pi/180) * r_earth * cos(theta*pi/180)

where theta is the latitude in degrees and r_earth is approximately 6378 km.

The number of kilometers per degree of latitude is approximately the same at all locations, approx

(pi/180) * r_earth = 111 km / degree 

So you can do:

new_latitude  = latitude  + (dy / r_earth) * (180 / pi);
new_longitude = longitude + (dx / r_earth) * (180 / pi) / cos(latitude * pi/180);

As long as dx and dy are small compared to the radius of the earth and you don't get too close to the poles.

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