Openlayers markers offset (not at the right place)

Question

I am using a Web Features Service (WFS) and I want to display a marker on a OpenLayers map. Extract of WFS's response :

<?xml version="1.0" encoding="ISO-8859-1"?>
<wfs:FeatureCollection>
    <gml:boundedBy>
        <gml:Envelope srsName="EPSG:900913">
            <gml:lowerCorner>-89132.899298 5581504.864113</gml:lowerCorner>
            <gml:upperCorner>-51735.101149 5625545.655457</gml:upperCorner>
        </gml:Envelope>
    </gml:boundedBy>
    <gml:featureMember>
        <bm:TB_ARRET_P gml:id="TB_ARRET_P.3473">
            <gml:boundedBy>
                <gml:Envelope srsName="EPSG:900913">
                    <gml:lowerCorner>-75379.857910 5601410.987374</gml:lowerCorner>
                    <gml:upperCorner>-75379.857910 5601410.987374</gml:upperCorner>
                </gml:Envelope>
            </gml:boundedBy>
            <bm:geometry>
                <gml:Point srsName="EPSG:900913">
                    <gml:pos>-75379.857910 5601410.987374</gml:pos>
                </gml:Point>
            </bm:geometry>
            <bm:LIGNEDES>Citéis 72/Lianes 3</bm:LIGNEDES>
            <bm:MOBILIE1>Poteau</bm:MOBILIE1>
            <bm:NOMARRET>Mairie du Haillan</bm:NOMARRET>
            <bm:VILLE>LE HAILLAN</bm:VILLE>
        </bm:TB_ARRET_P>
        <bm:TB_ARRET_P>
            ...
        </bm:TB_ARRET_P>
    </gml:featureMember>
</wfs:FeatureCollection>

I use OpenLayers to display a marker with the code below :

const f = new Feature({geometry: new Point([-75379.857910, 5601410.987374])});

const orangePoint = new Style({
    image: new CircleStyle({
        radius: 5,
        fill: new Fill({color: 'red'}),
        stroke: new Stroke({color: 'red', width: 3})
    })
});

f.setStyle(orangePoint);

const map = new Map({
    layers: [
        new TileLayer({ source: new XYZ({ url: this.mapboxTile }) }),
        new VectorLayer({
          source: new VectorSource({
            features: [f]
          })
        })
      ],
      target: this.idMaps$,
      view: new View({
        projection: 'EPSG:3857', // OpenLayers' default project and alias of 900913
        center: [-64436.414844, 5595687.311159],
        zoom: 12
      })
    });

So, here is the result :

So, the marker is displayed but it is not well located. What am I missing ? How to center the marker upon the bus station 'Mairie' ?

Thank you for your answers !

Mike · Accepted Answer · 2020-02-02T20:59:31.817

0

If I center OpenStreetMap on -75379.857910, 5601410.987374 it shows Mairie at the same location as your marker, so either both OpenStreetMap and your WFS data are wrong or your basemap shows Mairie in the wrong place.

Google Streetview confirms the stop in the same location https://www.google.com/maps/@44.8721247,-0.6771454,3a,25.7y,245.69h,82.65t/data=!3m6!1e1!3m4!1sPPVzzjGN24V3Z9FXMZTmrA!2e0!7i16384!8i8192?hl=en-GB so your marker is correct and the basemap is wrong.

edited Feb 02 '20 at 20:59

answered Feb 02 '20 at 20:42

Mike

16,042
2
14
30

Maybe this is a question of resolution. Does the map resolution can impact the precision of the marker ? – Orion Aurore Feb 03 '20 at 15:45
No the Mairie **bus stop** is south of Allée de l'Europe. That is confirmed by the streetview camera. The basemap which shows it north of Allée de l'Europe is wrong. It is the Mairie **building** which is north of Allée de l'Europe. – Mike Feb 03 '20 at 17:38

Openlayers markers offset (not at the right place)

1 Answers1