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Geodesic Distance

Geodesic Distance

Geodesic Distance is the shortest distance measured along the ellipsoidal surface of the earth. The tool named “Geodesic Distance” calculate distance between two points which are defined by geodetic coordinates in terms of latitude and longitude.  The geodetic coordinates must be based on WGS84.

When start the Surveyor Pocket Tools, You will see the main window that shows the Geodesic Distance tool.

Double click the Geodesic Distance icon and the tool will be displayed as the screenshot below. The tool is simplicity form. The left panel consists the text boxes to be input the geodetic coordinates which same as the right panel. There are angle display formats to define for both input left and right side. The middle of the tool is a  button to compute the geodesic distance. In addition, like the another tools, the button use to store the geodetic coordinates into Geo Database, the  button use to display the database table and restore the coordinates by the mean of drag and drop from the table to the input text boxes. The  button use to pin the location to Google Maps and the  use to save KML file and display on Google Earth.

Define Display Formats and Input Geodetic Coordinates

There are many possible display formats for geographic or geodetic coordinates (latitude/longitude). Follow the link below for tutorial how to define angle display settings and input geodetic coordinates.

How to define angle display formats and input geodetic coordinates?

Store the Point to Database and Restore the point from database

If you need to save a input or output point into database called Geo Database. Please follow the tutorial link:

How to use Geo Database?

Compute Geodesic Distance

Compute the shortest path between two points on a ellipsoid (coordinate1: lat1, long1) and (coordinate2: lat2, long2).

Exampe 1

Compute the geodesic distance between two given points:

• coordinate1: point name = “GC-503”, latitude = 14.6132366944, longitude =  98.0263297972 (the angle display format is decimal degree)
• coordinate2: point name = “AC-01-GPS”, latitude = 14°27’26.99575″N, longitude =  100°54’12.57538″E (the angle display format is DD°MM’SS.SSSS”)

Enter the coordinate values (point name, latitude and longitude) of coordinate1 on the left panel and the coordinate2 on the right panel.

Click the  to compute the geodesic distance that the result is “310.575 Km“. Please note you can change the unit of distance that are available in kilometer and meter.

Pin to Google Maps

Click the  button to display the line that connected two points. Please note the green marker that labeled with “1” is coordinate1, the orange markers with labeled “2” represent coordinate2.

Save to KML file and Display in Google Earth

Click the  button then save file dialog will be populated and you browse to the folder you want to keep the file and type name of the file and click “Save”. If your PC was installed Google Earth then the tool will activate it and display the geodesic distance line.

Example 2

Compute the geodesic distance from  Valparaíso, latitude = −33°, longitude = −71.6°, to Shanghai, lattitude = 31.4°, longitude = 121.8°.

Enter the coordinate values on the appropriate text boxes and select angle display format that relevant to input values, then click  to compute the distance.

The geodesic distance is “18752 km.

Pin to Google Maps

Click the  button to draw the line and pin the markers on Google Maps. You will notice that the geodesic line is a s-curved line on the conformal projection.

Save to KML file and Display on Google Earth

Click the  button then save the KML file to your folder and take a look at Google Earth.

Due to the geodesic line is too long so you cannot see the start and the end of the line at the same view on Google Earth. You need to rotate the globe.

Conclusion

The Geodesic Distance tool perform an easy calculation of the shortest distance on the ellipsoid surface which the results is very accurate.