Monday, March 25, 2024

Convert Earth Centered Earth Fixed to/from other coordinate systems with this web app Koordinat2

According to Wikipedia https://en.wikipedia.org/wiki/Earth-centered%2C_Earth-fixed_coordinate_system: in today's modern age of navigation and spatial referencing, there's a key player that often goes unnoticed: the Earth-centered, Earth-fixed coordinate system, more commonly known as ECEF. This sophisticated system, akin to a cosmic GPS, allows us to pinpoint locations with incredible precision. Picture this: a cartesian grid that not only encompasses the Earth's surface but also delves deep into its core, reaches high into the atmosphere, and extends into the surrounding outer space. Through X, Y, and Z measurements from the Earth's center of mass, ECEF opens up a world of possibilities for mapping and exploration.

The WebApp Koordinat2 here on https://dominoc925-pages.appspot.com/webapp/koordinat2/default.html has been enhanced to include conversions between ECEF and various other geo-coordinate systems.  

The following shows how to use convert ECEF to/fro longitude, latitude, altitude WGS84.

Define ECEF as the Primary coordinates (input)

  1. Open a browser to the Koordinat2 web app url https://dominoc925-pages.appspot.com/webapp/koordinat2/default.html.

    The Koordinat2 web app home page is displayed.


  2. In the Primary coordinates input card, click the gear icon.

    The Primary coordinates selection dialog box appears with a list of favorite coordinate systems.



  3. Click the ECEF item from the favorite list, or search for it by clicking the Search icon and typing in ECEF.





Define WGS 84 as the Secondary coordinates (output)

  1. In the Secondary coordinates card, click the gear icon.

    The Secondary coordinates favorites list is displayed.


  2. Click on the WGS 84 item from the favorites list, or click the Search icon and typing in WGS 84 to search for it.



Enter ECEF coordinates

  1. In the Primary coordinates card, type in the X, Y, and Z ECEF values.

    The ECEF values are converted to the secondary WGS 84 coordinates. A marker appears on the map.



Monday, March 18, 2024

Convert North East Down (NED) to/from longitude,latitude and other various coordinate systems

The Koordinat2 web app (https://dominoc925-pages.appspot.com/webapp/koordinat2/default.html) has been upgraded to perform coordinate transformation between local coordinate system North East Down (NED) and many other coordinate systems including MGRS, geographic longitude/latitude, etc. 

This post shows the typical steps to perform the local NED conversion to other coordinate systems.

Define the NED local origin 

The local origin should be as near as possible to the area of interest. If it is too far away, the calculation rounding errors would result in erroneous converted coordinates.

  1. Use a browser to open the Koordinat2 web app url (https://dominoc925-pages.appspot.com/webapp/koordinat2/default.html).

    The Koordinat2 web app home page appears.


  2. Click the hamburger menu icon on the top left.

    The Navigation drawer opens.



  3. Click the Settings item.

    The Settings dialog appears.


  4. Choose the item North East Down reference origin.

    The NED Reference Origin appears.


  5. In the dialog, enter the reference origin Longitude, Latitude, and Altitude. Click Save.

    The Reference Origin is saved.

Define NED as the Primary coordinates (input)

  1. In the Primary coordinates card, click the gear icon.

    The Primary coordinates selection appears.




  2. Select North East Down from the list or search for it by clicking the Search icon and typing in NED.


Define the Secondary coordinates (output)

  1. In the Secondary coordinates card, click the gear icon.

    The Secondary coordinates selection appears.



  2. Select a desired coordinate system e.g. WGS 84 from the list or search for it by clicking the Search icon and typing in  WGS 84.


Enter NED coordinates

  1. In the Primary coordinates card, type in the North, East, and Down values.

    The NED values are converted to the secondary coordinates. And a marker appears on the map.