fgdc spatial reference - resolution

[stansmith907]

The FGDC definition for geographic is "the quantities of latitude and longitude which define the position of a point on the Earth's surface with respect to a reference spheroid". This is representative of our *spatialResolution" class. The elements within this compound structure are latitudeResolution, longitudeResolution, and coordinateUnits.

However, moving this to mdJson/mdTranslator causes a problem. The ISO implementation allows only a single measure for resolution ( one of [ scaleFactor | measure | levelOfDetail ] ). Options:

• change measure to and array; this would be a breaking change to the schema

   def newSpatialResolution
      {
         scaleFactor: nil,
         measure: [],
         levelOfDetail: nil
      }
   end

• add x, y, and z values to measure

   def newMeasure
      {
         type: nil,
         value: nil,
         xValue: nil,
         yValue: nil,
         zValue: nil,
         unitOfMeasure: nil
      }
   end

• add new type geographicMeasure to spatialResolution

   def newSpatialResolution
      {
         scaleFactor: nil,
         measure: {},
         geographicResolution: {
            latitudeResolution: nil,
            longitudeResolution: nil,
            unitOfMeasure: nil
         },
         levelOfDetail: nil
      }
   end

   def newGeographicMeasure 
      {
         latitudeMeasure: nil,
         longitudeMeasure: nil,
         unitOfMeasure: nil
      }
   end