Positional Accuracy

[etj]

We need to handle the value for Positional Accuracy.
The element is a gco:Real and has cardinality [1].
The UoM is fixed to meter.

We need to implement changes in:

• [x] model
• [x] GUI
• [x] xml template

Model

As for the resolutions, the new field will be stored in LayerRNDT.
We're storing the value in meters, and the precision should be in the order of the cm, so 2 decimal digits shold be enough.

GUI

The panel for the Positional Accuracy (Accuratezza posizionale) could be placed just below the Resolution panel.

xml template

In the template there is already the element related to the gmd:DQ_AbsoluteExternalPositionalAccuracy with a fixed placeholder value 1.0; the placeholder should be replaced with the proper value:

         <gmd:DQ_AbsoluteExternalPositionalAccuracy>
            <gmd:result>
               <gmd:DQ_QuantitativeResult>
                  <gmd:valueUnit>
                     <gml:BaseUnit gml:id="UD1">
                        <gml:identifier 
                           codeSpace="http://www.bipm.org/en/si/base_units">m</gml:identifier>
                        <gml:unitsSystem xlink:href="http://www.bipm.org/en/si"/>
                     </gml:BaseUnit>
                  </gmd:valueUnit>
                  <gmd:value>
                     <gco:Record> 
                        {# TODO #}
                        <gco:Real>1.0</gco:Real>
                     </gco:Record>
                  </gmd:value>
               </gmd:DQ_QuantitativeResult>
            </gmd:result>
         </gmd:DQ_AbsoluteExternalPositionalAccuracy>