Batch Convert Coordinates using the Koordinat2 app

 

A batch coordinates conversion tool has been added to the Koordinat2 web app (https://dominoc925-pages.appspot.com/webapp/koordinat2/default.html) to perform bulk coordinates transformation between coordinate systems. 

This post shows how to use the Batch Coordinates Converter.

Launch the Batch Coordinates Converter

1. Use a browser to open the Koordinat2 web app url (https://dominoc925-pages.appspot.com/webapp/koordinat2/default.html).
   
   
   
   
   
2. Tap the hamburger icon on the top left.
   
   The Navigation drawer appears.
   
   
   
   
3. Tap the Batch Coordinates Converter list item.
   
   The Batch Coordinates Converter screen appears.
   
   
   

Define the Primary Coordinate System

1. In the Primary Coordinates card, click the gear icon.
   
   The Primary coordinates selection appears.
   
   
   
2. Select a coordinate system from the list or search for it by clicking the Search icon and typing in the name of the coordinate system e.g. MGRS.
   
   MGRS is selected as the primary coordinate system.
   
   

Define the Secondary Coordinate System

1. In the Secondary Coordinates card, click the gear icon.
   
   The Secondary Coordinates screen appears.
   
   
   
2. Select a coordinate system from the list or search for it by clicking the Search icon and typing in the name of the coordinate system e.g. WGS 84.
   
   WGS 84 geographic is selected as the secondary coordinate system.
   
   

Enter the coordinates and perform the conversion

1. In the Primary Coordinates text field, type or paste in the coordinates to convert.
   
   
   
   
2. Click the right arrow to convert from primary to secondary coordinate system.
   
   The coordinates are converted.
   

   

Convert East North Up (ENU) 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 East North Up (ENU) and many other coordinate systems including MGRS, North East Down, ECEF, geographic longitude/latitude, etc. 

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

Define the ENU 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/East North Up reference origin.
   
   The NED/ENU Reference Origin appears.
   
   
   
   
5. In the dialog, enter the reference origin Longitude, Latitude, and Altitude. Click Save.
   
   The Reference Origin is saved.
   
   

Define ENU as the Primary coordinates (input)

1. In the Primary coordinates card, click the gear icon.
   
   The Primary coordinates selection appears.
   
   
   
   
   
2. Select East North Up from the list or search for it by clicking the Search icon and typing in ENU.
   
   
   
   

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. MGRS from the list or search for it by clicking the Search icon and typing in  MGRS.
   
   
   
   

Enter ENU coordinates

1. In the Primary coordinates card, type in the East, North and Up values.
   
   The ENU values are converted to the secondary coordinates. And a marker appears on the map.
   
   
   
   
   

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.
   
   
   
   
   
   

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.
   
   
   
   

Using Koordinat2 webapp to convert between SVY21 and geographical coordinates

This is a follow up to the original post https://dominoc925.blogspot.com/2021/02/koordinat2-webapp-for-geo-coordinates.html, which describes a generic coordinate conversion steps. This post shows how to specifically use the Koordinat2 webapp https://dominoc925-pages.appspot.com/webapp/koordinat2/default.html to convert from WGS 84 latitude, longitude coordinates to SVY21 projected easting and northing coordinates, and vice versa.

Select the WGS 84 lat, lon as the source coordinate system

1. Using a modern browser, open the url https://dominoc925-pages.appspot.com/webapp/koordinat2/default.html.
   
   The Koordinat2 web app appears in the browser.
   
   
   
   
   
2. In the Input Coordinates card, click the gears icon labeled 1 in the screen above.
   
   The Select Source Coordinate System dialog appears.
   
   
   
3. In the Search field, type in a partial string for the WGS84 latitude, longitude system, e.g. "4326" or "WGS 84".
   
   A list of matches appear.
   
   
   
   
   
   
4. Click the WGS 84 list item.
   
   The WGS 84 geographic coordinate system is selected.

Select the destination SVY21 coordinate system

1. In the Output Coordinates card, click the gear icon (labeled 2 in the screen below).
   
   
   
   
    
   
   The Select Destination Coordinate System dialog appears.
   
   
   
2.  In the Search field, type in a partial string for SVY21, e.g. "3414" or "SVY21".
   
   A list of matching coordinate systems appears.
   
   
   
3. Click the SVY21 / Singapore TM list item.
   
   The destination coordinate system is selected.
   
   
   

Performing coordinate conversions from latitude, longitude to SVY21

1. In the Input Coordinates card, enter the Longitude and Latitude values.
   
   The Longitude/Latitude coordinates are dynamically converted and displayed in the Output Coordinates card.
   
   
2. Optional. If you wish to see the location of the coordinates on the map, click the marker icon as shown below.
   
   
   
   
   
   The location is marked by a marker on the map.
   
   
   
   
   

Performing coordinate conversion from SVY21 to WGS84 latitude, longitude

If you wish to perform the reverse conversion, simply repeat the previous steps but reverse the coordinate system selections.

 

 

React JS Material UI icons for Mastodon and Blogger

Other than the Linkedin icon, I couldn't find the Mastodon and Blogger React Material UI (MUI) icons in the React @mui/icons-material library so I had to make my own with Inkscape and a good old text editor. The results are shown in the screenshot below.

 Here is the MastodonIcon.js code for the Mastodon icon:

import * as React from 'react';
import SvgIcon from '@mui/material/SvgIcon';

export default function MastodonIcon() {
  return (
    <SvgIcon>
      <svg className="mastodon" width="16" height="16" fill="currentColor" version="1.1" viewBox="0 0 16 16" xmlns="http://www.w3.org/2000/svg">
        <path d="m10.751 11.617c1.7387-0.20699 3.2514-1.2721 3.4412-2.2449 0.30012-1.5334 0.27598-3.7421 0.27598-3.7421 0-2.9926-1.9715-3.8706-1.9715-3.8706-0.99355-0.45451-2.7002-0.6451-4.4734-0.65976h-0.043122c-1.774 0.014661-3.48 0.20526-4.4734 0.65976 0 0-1.9706 0.87709-1.9706 3.8706l-0.00173 0.57093c-0.00345 0.55195-0.00603 1.1643 0.0095 1.8033 0.071582 2.9271 0.53988 5.8128 3.26 6.5286 1.2539 0.33031 2.3311 0.39931 3.1988 0.35188 1.5722-0.08625 2.4554-0.55799 2.4554-0.55799l-0.05176-1.1358s-1.1237 0.3536-2.3864 0.31047c-1.2505-0.04312-2.57-0.13454-2.7728-1.6628a3.1169 3.1169 0 0 1-0.028456-0.42777s1.2281 0.2984 2.784 0.36912c0.95126 0.04312 1.843-0.0552 2.7495-0.163zm1.3911-2.1302h-1.4429v-3.5188c0-0.74083-0.31393-1.1168-0.94091-1.1168-0.69339 0-1.041 0.44587-1.041 1.329v1.9258h-1.4351v-1.9266c0-0.88313-0.34756-1.329-1.041-1.329-0.62699 0-0.94091 0.37602-0.94091 1.1177v3.5179h-1.4429v-3.6239c0-0.74083 0.18973-1.329 0.56921-1.7646 0.39327-0.43553 0.90728-0.6589 1.5463-0.6589 0.73824 0 1.2971 0.28288 1.6671 0.84777l0.35964 0.5994 0.35964-0.5994c0.36998-0.5649 0.92884-0.84777 1.668-0.84777 0.6382 0 1.1522 0.22337 1.5446 0.6589 0.38119 0.43553 0.57007 1.0237 0.57007 1.7646z" strokeWidth=".86244" />
      </svg>
    </SvgIcon>
  );
}

And here is the BloggerIcon.js code for the Blogger icon:

import * as React from 'react';
import SvgIcon from '@mui/material/SvgIcon';

export default function SvgIconChildren() {
  return (
    <SvgIcon>
      <svg width="50.664mm" height="50.575mm" version="1.1" viewBox="0 0 179.52 179.2" xmlns="http://www.w3.org/2001/svg">
        <defs>
          <clipPath id="clipPath8">
            <path d="m111.47 137.84c6.8936-0.96075 12.296-3.7837 17.364-9.0736 3.6662-3.8268 5.9611-7.9689 7.4609-13.466 0.62305-2.2837 0.67529-3.3956 0.78946-16.804 0.0863-10.12 0.0143-14.86-0.24367-16.056-0.37384-1.7344-1.4336-3.345-2.6427-4.0165-0.37209-0.20664-2.7561-0.47002-5.2978-0.58526-4.2591-0.19314-4.7356-0.278-6.08-1.0829-2.1324-1.2768-2.7197-2.6555-2.7255-6.3987-0.0111-7.152-2.9243-13.792-8.6802-19.785-4.1006-4.2694-8.6751-7.1592-13.896-8.7785-1.2498-0.38765-4.0484-0.51957-13.422-0.63274-14.708-0.17757-17.973 0.13047-22.98 2.1682-9.2314 3.7568-15.864 11.674-18.284 21.824-0.45444 1.9064-0.54266 4.9618-0.65 22.513-0.13448 21.988 0.01386 25.217 1.3586 29.575 1.111 3.6002 2.232 5.8063 4.5414 8.9376 4.3994 5.9652 10.993 10.273 17.585 11.49 3.137 0.57911 41.84 0.72399 45.804 0.17161z" display="none" fill="#fff" strokeWidth=".86401" />
            <path className="clip" d="m8.0345 6.3499h163.45v166.5h-163.45zm103.44 131.49c6.8936-0.96075 12.296-3.7837 17.364-9.0736 3.6662-3.8268 5.9611-7.9689 7.4609-13.466 0.62305-2.2837 0.67529-3.3956 0.78946-16.804 0.0863-10.12 0.0143-14.86-0.24367-16.056-0.37384-1.7344-1.4336-3.345-2.6427-4.0165-0.37209-0.20664-2.7561-0.47002-5.2978-0.58526-4.2591-0.19314-4.7356-0.278-6.08-1.0829-2.1324-1.2768-2.7197-2.6555-2.7255-6.3987-0.0111-7.152-2.9243-13.792-8.6802-19.785-4.1006-4.2694-8.6751-7.1592-13.896-8.7785-1.2498-0.38765-4.0484-0.51957-13.422-0.63274-14.708-0.17757-17.973 0.13047-22.98 2.1682-9.2314 3.7568-15.864 11.674-18.284 21.824-0.45444 1.9064-0.54266 4.9618-0.65 22.513-0.13448 21.988 0.01386 25.217 1.3586 29.575 1.111 3.6002 2.232 5.8063 4.5414 8.9376 4.3994 5.9652 10.993 10.273 17.585 11.49 3.137 0.57911 41.84 0.72399 45.804 0.17161z" strokeWidth=".86401" />
          </clipPath>
        </defs>
        <path d="m-82.995 87.838v-171.9h1020v343.8h-1020v-171.9z" fill="none" />
        <g transform="matrix(.92141 0 0 .92141 7.0545 7.0421)" fill="#fff" strokeWidth=".86401">
          <path d="m30.568 167.24c-2.8716-0.77176-5.3495-1.9071-7.6348-3.4982-1.9292-1.3431-4.7488-4.1198-5.8212-5.7323-1.3096-1.9694-2.815-5.342-3.4285-7.6809-0.62576-2.3858-0.6359-3.336-0.64713-60.605-0.01116-56.98 0.0015-58.233 0.61488-60.681 2.169-8.6596 8.8857-15.248 17.548-17.214 2.4907-0.56514 113.75-0.66398 116.44-0.10343 7.2734 1.5175 12.991 5.979 16.299 12.719 2.6303 5.3583 2.3951-0.53816 2.5156 63.081 0.0767 40.479 6e-3 57.473-0.24689 59.59-1.1845 9.9072-7.8732 17.592-17.498 20.103-2.462 0.64225-3.3184 0.65142-59.215 0.63395-54.046-0.0166-56.821-0.0454-58.928-0.61194z" clipPath="url(#clipPath8)" />
          <path d="m70.797 77.476c-3.5242-0.9925-4.841-6.1585-2.2508-8.8303 1.6555-1.7077 2.1132-1.7727 12.476-1.7727 9.3029 0 9.6156 0.02079 10.982 0.72599 1.9748 1.0193 2.8328 2.4564 2.8328 4.7444 0 2.0665-0.80586 3.5146-2.6034 4.6784-0.96518 0.62486-1.542 0.66375-10.657 0.71844-5.6283 0.0338-10.112-0.07615-10.78-0.26416zm-0.44157 34.766c-1.5128-0.67346-2.9215-2.5442-3.165-4.203-0.23192-1.5801 0.54532-3.7524 1.7367-4.854 1.5018-1.3886 2.161-1.435 20.63-1.4498 18.999-0.0152 18.9-0.0234 20.701 1.6952 2.5446 2.4274 2.0078 6.749-1.0585 8.5234l-3.151 0.52354-16.423 0.19641c-14.431 0.17258-18.519-0.0973-19.271-0.43172z" />
        </g>
      </svg>
    </SvgIcon>
  );
}

Hope these help somebody.

WebApp for Singapore Weather forecasts rewritten using Flutter

I thought the old Singapore Weather Nowcast WebApp at this site https://dominoc925-pages.appspot.com/webapp/weather_sg/default.html written using the AngularJS framework and Bootstrap was a good candidate for a Flutter app. So I rolled up the sleeves and rewrote it using Flutter. Now it has Material design and this is how it looks and works.

4 day outlooks

For the Flutter version, I included additional data from the National Environment Agency (NEA)'s 4 day outlooks with temperature, wind and humidity values.

2 hour nowcasts

The 2 hour weather nowcast is now displayed in a responsive 2 pane display.

On small screens, a tab bar will appear displaying the nowcast list and map on separate tabs. 

 

24 hour forecasts

The new 24 hour forecasts are separated by 3 tabs as shown in the screenshot below. Clicking each tab will show the forecast for that time period. And like the 2 hour nowcast display, the 24 hour forecasts display is also responsive to screen sizes.

To try out the new Flutter WebApp, visit this web site: https://dominoc925-pages.appspot.com/webapp/weather_sg/default.html.

Convert Geoids from BYN to GTX format with this WebApp

This WebApp came about because I wanted to use some Geoid files for some vertical datum corrections with Proj (which uses .gtx format) but could only find Geoid files in Natural Resources Canada's .byn format.

1. To convert Geoid BYN files to GTX, open up a browser to the following url: https://dominoc925-pages.appspot.com/webapp/byn2gtx/index.html.
   
   
   The WebApp is loaded.
   
   
   
   
   
   
   
   
   
    
2. Click the Add File button.
   
   The File Upload dialog appears.
   
   
   
   
   
3. Browse and select a .byn file e.g. EGM96.byn. Click Open.
   
   
   The Geoid file is displayed in a list and the Convert button is enabled.
   
   
   Note: the Geoid .byn is loaded locally to the browser and not transferred to some server on the Internet.
   
   
   
   
4. Click the Convert button.
   
   The Geoid file is converted into .gtx format and the Process log and Save As icons are enabled.
   
   
   
   
   
   
5. Optional. To view the process log, click the Show Process Log icon.
   
   The process log messages are displayed.
   
   
   
   
   
   
6. To save the converted .gtx Geoid locally, click the Save Converted File icon.
   
   The Geoid file is saved.
   
   
   
7. Optional. If necessary, you can use a GIS software like QGIS to display the converted .gtx file, as shown below.