How to style a point based on Actual Attribute Values?

Question

I have published a point layer in Geoserver, which is the data from a GPS Survey. In addition to the geometry, my layer, also contains an Attribute for Accuracy, which indicates the Accuracy in meters of the reading.

I have been trying to style the layer, such that a point is show as a point surrounded by a circle whose radius is equivalent to the Accuracy in map units. (Similar to how most mobile apps show the GPS points)

All of the Attribute based symbolization that I have seen is Rule based (i.e. Classification).

How do you Symbolize a point, such that its radius is equal to its accuracy?

Answer 1

Try an SLD like this, using ogc:PropertyName to include the accuracy value:

<?xml version="1.0" encoding="ISO-8859-1"?>
<StyledLayerDescriptor version="1.0.0" 
    xsi:schemaLocation="http://www.opengis.net/sld StyledLayerDescriptor.xsd" 
    xmlns="http://www.opengis.net/sld" 
    xmlns:ogc="http://www.opengis.net/ogc" 
    xmlns:xlink="http://www.w3.org/1999/xlink" 
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
  <NamedLayer>
    <Name>Attribute-based point</Name>
    <UserStyle>
      <FeatureTypeStyle>
        <Rule>
          <PointSymbolizer uom="http://www.opengeospatial.org/se/units/metre">
            <Graphic>
              <Mark>
                <WellKnownName>circle</WellKnownName>
                <Fill>
                  <CssParameter name="fill">#0033CC</CssParameter>
                  <CssParameter name="fill-opacity">0.1</CssParameter>
                </Fill>
              </Mark>
              <Size><ogc:PropertyName>Accuracy</ogc:PropertyName></Size>
            </Graphic>
          </PointSymbolizer>
          </PointSymbolizer>
            <PointSymbolizer>
             <Graphic>
               <Mark>
                <WellKnownName>circle</WellKnownName>
                 <Fill>
                  <CssParameter name="fill">#f00000</CssParameter>
                  <CssParameter name="fill-opacity">1.0</CssParameter>
                 </Fill>
               </Mark>
               <Size>7</Size>
               </Graphic>
            </PointSymbolizer>
        </Rule>
      </FeatureTypeStyle>
    </UserStyle>
  </NamedLayer>
</StyledLayerDescriptor>