Question

Write a program to calculate the great circle distance between two points on the surface of a sphere. If p1(x1, y1) and p2(x2,y2) are geographic latitude and longitude of two points, the great circle distance can be computed as

Answer 1

Answer:

import java.lang.*;

public class distance { public static double distance(double latitude1,

                                     double latitude2, double longitude1,

                                     double longitude2)

       {

      // Convert Latitude and Longitude to Radians

           longitude1 = Math.toRadians(longitude1);

           longitude2 = Math.toRadians(longitude2);

           latitude1 = Math.toRadians(latitude1);

           latitude2 = Math.toRadians(latitude2);

           

           double d_longitude = longitude2 - longitude1;

           double d_latitude = latitude2 - latitude1;

           double a = Math.pow(Math.sin(d_latitude / 2), 2)

                   + Math.cos(latitude1) * Math.cos(latitude2)

                   * Math.pow(Math.sin(d_longitude / 2),2);

           double val = 2 * Math.asin(Math.sqrt(a));

           // Radius of earth in kilometers is 6371

           double earth_radius = 6371;

           // Calculate and return the distance

           return(val * earth_radius);

       }

       // Main Method

       public static void main(String[] args)

       {

           double latitude1 = 67.32055555555556;

           double latitude2 = 83.31861111111111;

           double longitude1 = -1.7217899;

           double longitude2 = -1.6567799;

           System.out.println(distance(latitude1, latitude2,

                   longitude1, longitude2) + " K.M");

       }

   }

Explanation:

This program is implemented in Java programming language

The formula for the shortest distance between two points on the earth is:

Distance = 3963.0 * arccos[(sin(lat1) * sin(lat2)) + cos(lat1) * cos(lat2) * cos(long2 – long1)]

The latitude and longitude of the two points must be known

The latitude and longitude are converted into radians using built in methods in java.

Take value for the radius of the earth in Kilometers  6371;

Note that a seperate method has been created to calculate the distance

In the driver method (main), values for latitude and logitudes for both places have been hard-corded, then the method distance is called and passed those values

Note also that the distance has been calculated in Kilometers