Plot pushpin using WKT format

Question

Plot pushpin using WKT format

Balasaheb Molawade 136

Hi Team,

We have developed an application using Bing Maps. The customer has made a specific request: they have their data in Well-Known Text (WKT) format, including X and Y coordinates, as depicted in the screenshot below. In the application, we plot data using latitude and longitude. Are there any methods in Bing Maps to convert the WKT format, as shown below, into the corresponding latitude and longitude coordinates.

We have attempted the code provided in the link below, but when we input the WKT format mentioned above, it does not display a pushpin; instead, it shows an empty map.

  var pin = Microsoft.Maps.WellKnownText.read('POINT(998546 172742)');

https://learn.microsoft.com/en-us/bingmaps/v8-web-control/map-control-concepts/well-known-text-examples/well-known-text-read-example

Thanks!

LeelaRajeshSayana-MSFT 17,766 Reputation points Moderator

2023-09-01T17:30:55.68+00:00

Hi @Balasaheb Molawade Thank you for posting the question here. Looks like the image you tried to attach did not get added to the question. Can you share more details on the point coordinates format that you are referring to? I believe the point coordinates input should be valid latitude and longitude coordinates. The longitude coordinate should be between -180 and 180 and latiitude coordinate is between -90 and 90. Can you please confirm if your points need to be modified to fit in these limitations before passing to the Microsoft.Maps.WellKnownText.read API?

Please let us know if you need further clarification on this.

1 answer

Your answer

LeelaRajeshSayana-MSFT 17,766 Reputation points Moderator

2023-09-01T17:30:55.68+00:00

Hi @Balasaheb Molawade Thank you for posting the question here. Looks like the image you tried to attach did not get added to the question. Can you share more details on the point coordinates format that you are referring to? I believe the point coordinates input should be valid latitude and longitude coordinates. The longitude coordinate should be between -180 and 180 and latiitude coordinate is between -90 and 90. Can you please confirm if your points need to be modified to fit in these limitations before passing to the Microsoft.Maps.WellKnownText.read API?

Please let us know if you need further clarification on this.

Answer 1

Bing Maps (and Azure Maps) support Well Known Text format, but for WGS84 decimal degrees coordinates (EPSG:4326). The numbers in the code block you provided appear to be northing and easting values in another projection system. You will need to find out what project system that is as there are literally thousands that look like this. I'm fairly certain it isn't EPSG:3857 as that would put the coordinates in the Atlantic Ocean. I suspect it is either using a UTM or state plane type projection/coordinate reference system. To use this, the data would need to be reprojected. Ideally that would be done on the server side before it reaches the frontend app. If the data is stored in Postgresql, they are likely using PostGIS which supports reprojecting the data natively (simple modification to the SQL query). If they are using SQL, there is not native reprojection support, I believe there are some external libraries, but it may be better to simply reproject the data in the backend service that is serving the data using a common library, like NetTopologySuite, or Proj4Net. If you can't change the backend and need to handle this on the front end, you will need to either manually parse the WKT (not overly difficult) and reproject the points using something like proj4js. If you want to skip the manual parsing part and leverage libraries, the following is one method:

Convert the WKT to GeoJSON using https://github.com/mapbox/wellknown
Project the GeoJSON data using https://github.com/DanielJDufour/reproject-geojson
Use the Bing Maps GeoJSON module to load the data into the map.

Here is a code sample

<html>
<head>
	<title></title>
	<style>
	html, body, #myMap {
		[adding: 0;
		margin:0;
		width: 100%;
		height: 100%;
		position: relative;
	}
	</style>
</head>
<body>
	<div id="myMap"></div>
	
	<!-- Load a library to convert WKT to GeoJSON -->
	<script src="https://cdn.jsdelivr.net/npm/wellknown@0.5.0/wellknown.min.js"></script>

	<!-- Load library to reproject coordinates. -->
	<script src="https://cdn.jsdelivr.net/npm/proj4@2.9.0/dist/proj4.min.js"></script>

	<!-- Load a library to reproject GeoJSON -->
	<script src="https://cdn.jsdelivr.net/npm/reproject-geojson@0.3.0/reproject-geojson.min.js"></script>
	
	<script>
		var map;
	
		var inputWKT = 'POINT(998546 172742)';
	
		function GetMap(){
			map = new Microsoft.Maps.Map(document.getElementById('myMap'), {
				center: new Microsoft.Maps.Location(0,0),
				zoom: 1
			});
			
			//Load GeoJSON module for Bing Maps.
			Microsoft.Maps.loadModule('Microsoft.Maps.GeoJson', importWKTData); 
		}
		
		function importWKTData() {
			var geojson = wellknown.parse(inputWKT);
			
			//Change "3857" to the EPSG code for the coordinate reference system of the input data.
			var geojson4326 = reprojectGeoJSON(geojson, { from: 3857, to: 4326 });
			
			var shape = Microsoft.Maps.GeoJson.read(geojson4326, { 
				pushpinOptions: { color: 'red' },
				polylineOptions: { strokeColor: 'blue', strokeThickness: 5},
				polygonOptions: { fillColor: 'rgba(0, 255, 255, 0.3)' } 
			});
			
			map.entities.push(shape);
		}
	</script>
	
	<!-- Load Bing Maps SDK -->
	<script type='text/javascript' src='https://www.bing.com/api/maps/mapcontrol?callback=GetMap&key=YOUR_BING_MAPS_KEY' async defer></script>
</body>
</html>

Note, it's possible that your customer data may have a mix of coordinate reference systems (EPSG codes) if for instance they are using state plane coordinate systems for accuracy but have data that cross several states. In that case they should know the coordinate reference system for each row of their data and be able to pass that down with the WKT data as a property in the data. If you are creating a reusable solution, it would make sense to have a way to support multiple project systems like this to make your solution more reusable.

Balasaheb Molawade 136 Reputation points

2023-09-04T09:01:05.98+00:00

Hi Ricky,

Thanks for your reply. We have reviewed the code above, but it is plotting in the wrong location.

We have the X and Y coordinates in the WKT format, as shown below.

Is there a method to convert that into latitude and longitude?

We are not sure about the EPSG format.

Thanks!
Balasaheb Molawade 136 Reputation points

2023-09-07T11:53:30.46+00:00

Hi,

I'd like to follow up on this. Do you have any suggestions for the same

We received additional information from customers regarding the point (998546, 172742) obtained from the ArcGIS system.

Thanks!
LeelaRajeshSayana-MSFT 17,766 Reputation points Moderator

2023-09-11T21:28:03.81+00:00

Hi @rbrundritt Greetings! I am following up to see if you got a chance to review the above feedback from @Balasaheb Molawade . Does the code sample you have provided work for point obtained from ArcGIS system?
rbrundritt 20,916 Reputation points Microsoft Employee Moderator

2023-09-11T21:32:31.8133333+00:00

As I noted in my original response, the coordinate you have are not in WGS84 decimal degrees, and thus will not show up in the right location. You need to find out from your customer what projection that data is in (EPSG code). Without that, there is literally thousands of projection systems that convert that data to latitude and longitude values that will appear in a thousand different spots. Alternatively, if you have a couple of data points, and know the equivalent latitude and longitude values for them (or approximate), I can try and reverse engineer what the possible projection system by doing a bunch of math.
LeelaRajeshSayana-MSFT 17,766 Reputation points Moderator

2023-09-21T16:45:30.02+00:00

@Balasaheb Molawade I am following up to see if you got a chance to review the above feedback. Please let us know if you still need any additional assistance or further feedback on this. If the response helped answer your question, kindly mark it as Accept Answer and Yes to help other community members facing a similar issue find a solution.

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Plot pushpin using WKT format

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