2

I am trying to convert WGS84 coordinates (EPSG:4326) to Amersfoort RD New (EPSG:28992) with OpenLayers 3.

I declared EPSG28992:

Proj4js.defs["EPSG:28992"] = "+proj=sterea +lat_0=52.15616055555555 +lon_0=5.38763888888889 +k=0.9999079 +x_0=155000 +y_0=463000 +ellps=bessel +units=m +no_defs";

Got the projection from OL:

var EPSG28992 = new ol.proj.Projection('EPSG:28992');

Now I defined my transform function as:

function transformLatLong(lattitude, longitude)
{
    var coordinates = ol.proj.transform([longitude, lattitude], 'EPSG:4326', EPSG28992);
    console.log(coordinates);
}

The problem is that ol.proj.transform returns just the same long lat coordinates (i.e. did not transform anything).

What am I missing here?

1 Answer 1

2

You are using Proj4js 1.x series declaration whereas now OpenLayers 3 is using Proj4js 2.x series. For this reason, your projection is never registered within OpenLayers 3 and your coordinates reprojection fails.

More an addition that a direct answer but I'm wondering why you want to create a function for a one liner in OpenLayers 3 (but I don't know your context) whereas you can use ol.proj.fromLonLat function.

You will find below a sample including two approaches in one (through <script> tag or with a code declaration at the top of your own code)

<!DOCTYPE html>
<html>
<head>
  <meta charset=utf-8>
  <title>Proj4 demo</title>
  <meta name=description content="">
  <meta name=viewport content="width=device-width, initial-scale=1">
  <link rel="stylesheet" href="https://openlayers.org/en/v3.19.1/css/ol.css" type="text/css">
  <!-- The line below is only needed for old environments like Internet Explorer and Android 4.x -->
  <script src="https://cdn.polyfill.io/v2/polyfill.min.js?features=requestAnimationFrame,Element.prototype.classList,URL"></script>
  <script src="https://openlayers.org/en/v3.19.1/build/ol.js"></script>
  <script src="https://cdnjs.cloudflare.com/ajax/libs/proj4js/2.3.15/proj4.js"></script>
  <script src="https://epsg.io/28992.js"></script>
</head>
<body>
<script type="text/javascript">
  // Below code is optional if you use above url https://epsg.io/28992.js in script tag
  proj4.defs("EPSG:28992","+proj=sterea +lat_0=52.15616055555555 +lon_0=5.38763888888889 +k=0.9999079 +x_0=155000 +y_0=463000 +ellps=bessel +towgs84=565.417,50.3319,465.552,-0.398957,0.343988,-1.8774,4.0725 +units=m +no_defs");
  console.log(ol.proj.fromLonLat([5.2, 52.25], 'EPSG:28992'));
</script>

</body>
</html>
1
  • Thanks! That was it, good catch... Indeed the function as I posted it didn't make much sense as a one liner but it was supposed to do a bit more. Just for the sake of this question I stripped it down.
    – mastair
    Nov 14, 2016 at 19:36

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge that you have read and understand our privacy policy and code of conduct.

Not the answer you're looking for? Browse other questions tagged or ask your own question.