/// <summary>
        ///
        /// </summary>
        /// <param name="tokenizer"></param>
        /// <returns></returns>
        private static IHorizontalDatum ReadHorizontalDatum(WktStreamTokenizer tokenizer)
        {
            //DATUM["OSGB 1936",SPHEROID["Airy 1830",6377563.396,299.3249646,AUTHORITY["EPSG","7001"]]TOWGS84[0,0,0,0,0,0,0],AUTHORITY["EPSG","6277"]]
            Wgs84ConversionInfo wgsInfo = null;
            string authority            = String.Empty;
            long   authorityCode        = -1;

            tokenizer.ReadToken("[");
            string name = tokenizer.ReadDoubleQuotedWord();

            tokenizer.ReadToken(",");
            tokenizer.ReadToken("SPHEROID");
            IEllipsoid ellipsoid = ReadEllipsoid(tokenizer);

            tokenizer.NextToken();
            while (tokenizer.GetStringValue() == ",")
            {
                tokenizer.NextToken();
                if (tokenizer.GetStringValue() == "TOWGS84")
                {
                    wgsInfo = ReadWGS84ConversionInfo(tokenizer);
                    tokenizer.NextToken();
                }
                else if (tokenizer.GetStringValue() == "AUTHORITY")
                {
                    tokenizer.ReadAuthority(ref authority, ref authorityCode);
                    tokenizer.ReadToken("]");
                }
            }
            // make an assumption about the datum type.
            IHorizontalDatum horizontalDatum = new HorizontalDatum(ellipsoid, wgsInfo, DatumType.HD_Geocentric, name, authority, authorityCode, String.Empty, String.Empty, String.Empty);

            return(horizontalDatum);
        }
        /*
         * /// <summary>
         * ///
         * /// </summary>
         * /// <param name="tokenizer"></param>
         * /// <returns></returns>
         * private static ICompoundCoordinateSystem ReadCompoundCoordinateSystem(WktStreamTokenizer tokenizer)
         * {
         *
         *      //COMPD_CS[
         *      //"OSGB36 / British National Grid + ODN",
         *      //PROJCS[]
         *      //VERT_CS[]
         *      //AUTHORITY["EPSG","7405"]
         *      //]
         *
         *      tokenizer.ReadToken("[");
         *      string name=tokenizer.ReadDoubleQuotedWord();
         *      tokenizer.ReadToken(",");
         *      tokenizer.NextToken();
         *      string headCSCode =  tokenizer.GetStringValue();
         *      ICoordinateSystem headCS = ReadCoordinateSystem(headCSCode,tokenizer);
         *      tokenizer.ReadToken(",");
         *      tokenizer.NextToken();
         *      string tailCSCode =  tokenizer.GetStringValue();
         *      ICoordinateSystem tailCS = ReadCoordinateSystem(tailCSCode,tokenizer);
         *      tokenizer.ReadToken(",");
         *      string authority=String.Empty;
         *      string authorityCode=String.Empty;
         *      tokenizer.ReadAuthority(ref authority, ref authorityCode);
         *      tokenizer.ReadToken("]");
         *      ICompoundCoordinateSystem compoundCS = new CompoundCoordinateSystem(headCS,tailCS,String.Empty,authority,authorityCode,name,String.Empty,String.Empty);
         *      return compoundCS;
         *
         * }*/

        /// <summary>
        ///
        /// </summary>
        /// <param name="tokenizer"></param>
        /// <returns></returns>
        private static IEllipsoid ReadEllipsoid(WktStreamTokenizer tokenizer)
        {
            //SPHEROID["Airy 1830",6377563.396,299.3249646,AUTHORITY["EPSG","7001"]]
            tokenizer.ReadToken("[");
            string name = tokenizer.ReadDoubleQuotedWord();

            tokenizer.ReadToken(",");
            tokenizer.NextToken();
            double majorAxis = tokenizer.GetNumericValue();

            tokenizer.ReadToken(",");
            tokenizer.NextToken();
            double e = tokenizer.GetNumericValue();

            //

            //tokenizer.ReadToken(",");
            tokenizer.NextToken();
            string authority     = String.Empty;
            long   authorityCode = -1;

            if (tokenizer.GetStringValue() == ",")             //Read authority
            {
                tokenizer.ReadAuthority(ref authority, ref authorityCode);
                tokenizer.ReadToken("]");
            }
            IEllipsoid ellipsoid = new Ellipsoid(majorAxis, 0.0, e, true, LinearUnit.Metre, name, authority, authorityCode, String.Empty, string.Empty, string.Empty);

            return(ellipsoid);
        }
        /// <summary>
        /// Returns a <see cref="AxisInfo"/> given a piece of WKT.
        /// </summary>
        /// <param name="tokenizer">WktStreamTokenizer that has the WKT.</param>
        /// <returns>An AxisInfo object.</returns>
        private static AxisInfo ReadAxis(WktStreamTokenizer tokenizer)
        {
            if (tokenizer.GetStringValue() != "AXIS")
            {
                tokenizer.ReadToken("AXIS");
            }
            tokenizer.ReadToken("[");
            string axisName = tokenizer.ReadDoubleQuotedWord();

            tokenizer.ReadToken(",");
            tokenizer.NextToken();
            string unitname = tokenizer.GetStringValue();

            tokenizer.ReadToken("]");
            switch (unitname.ToUpper())
            {
            case "DOWN": return(new AxisInfo(axisName, AxisOrientationEnum.Down));

            case "EAST": return(new AxisInfo(axisName, AxisOrientationEnum.East));

            case "NORTH": return(new AxisInfo(axisName, AxisOrientationEnum.North));

            case "OTHER": return(new AxisInfo(axisName, AxisOrientationEnum.Other));

            case "SOUTH": return(new AxisInfo(axisName, AxisOrientationEnum.South));

            case "UP": return(new AxisInfo(axisName, AxisOrientationEnum.Up));

            case "WEST": return(new AxisInfo(axisName, AxisOrientationEnum.West));

            default:
                throw new ArgumentException("Invalid axis name '" + unitname + "' in WKT");
            }
        }
        /// <summary>
        ///
        /// </summary>
        /// <param name="tokenizer"></param>
        /// <returns></returns>
        private static IProjection ReadProjection(WktStreamTokenizer tokenizer)
        {
            //tokenizer.NextToken();// PROJECTION
            tokenizer.ReadToken("PROJECTION");
            tokenizer.ReadToken("[");            //[
            string projectionName = tokenizer.ReadDoubleQuotedWord();

            tokenizer.ReadToken("]");            //]
            tokenizer.ReadToken(",");            //,
            tokenizer.ReadToken("PARAMETER");
            List <ProjectionParameter> paramList = new List <ProjectionParameter>();

            while (tokenizer.GetStringValue() == "PARAMETER")
            {
                tokenizer.ReadToken("[");
                string paramName = tokenizer.ReadDoubleQuotedWord();
                tokenizer.ReadToken(",");
                tokenizer.NextToken();
                double paramValue = tokenizer.GetNumericValue();
                tokenizer.ReadToken("]");
                tokenizer.ReadToken(",");
                paramList.Add(new ProjectionParameter(paramName, paramValue));
                tokenizer.NextToken();
            }
            string      authority     = String.Empty;
            long        authorityCode = -1;
            IProjection projection    = new Projection(projectionName, paramList, projectionName, authority, authorityCode, String.Empty, String.Empty, string.Empty);

            return(projection);
        }
        /// <summary>
        ///
        /// </summary>
        /// <param name="tokenizer"></param>
        /// <returns></returns>
        private static IGeographicCoordinateSystem ReadGeographicCoordinateSystem(WktStreamTokenizer tokenizer)
        {
            /*
             * GEOGCS["OSGB 1936",
             * DATUM["OSGB 1936",SPHEROID["Airy 1830",6377563.396,299.3249646,AUTHORITY["EPSG","7001"]]TOWGS84[0,0,0,0,0,0,0],AUTHORITY["EPSG","6277"]]
             * PRIMEM["Greenwich",0,AUTHORITY["EPSG","8901"]]
             * AXIS["Geodetic latitude","NORTH"]
             * AXIS["Geodetic longitude","EAST"]
             * AUTHORITY["EPSG","4277"]
             * ]
             */
            tokenizer.ReadToken("[");
            string name = tokenizer.ReadDoubleQuotedWord();

            tokenizer.ReadToken(",");
            tokenizer.ReadToken("DATUM");
            IHorizontalDatum horizontalDatum = ReadHorizontalDatum(tokenizer);

            tokenizer.ReadToken(",");
            tokenizer.ReadToken("PRIMEM");
            IPrimeMeridian primeMeridian = ReadPrimeMeridian(tokenizer);

            tokenizer.ReadToken(",");
            tokenizer.ReadToken("UNIT");
            IAngularUnit angularUnit = ReadAngularUnit(tokenizer);

            string authority     = String.Empty;
            long   authorityCode = -1;

            tokenizer.NextToken();
            List <AxisInfo> info = new List <AxisInfo>(2);

            if (tokenizer.GetStringValue() == ",")
            {
                tokenizer.NextToken();
                while (tokenizer.GetStringValue() == "AXIS")
                {
                    info.Add(ReadAxis(tokenizer));
                    tokenizer.NextToken();
                }
                if (tokenizer.GetStringValue() == "AUTHORITY")
                {
                    tokenizer.ReadAuthority(ref authority, ref authorityCode);
                    tokenizer.ReadToken("]");
                }
            }
            //This is default axis values if not specified.
            if (info.Count == 0)
            {
                info.Add(new AxisInfo("Lon", AxisOrientationEnum.East));
                info.Add(new AxisInfo("Lat", AxisOrientationEnum.North));
            }
            IGeographicCoordinateSystem geographicCS = new GeographicCoordinateSystem(angularUnit, horizontalDatum,
                                                                                      primeMeridian, info, name, authority, authorityCode, String.Empty, String.Empty, String.Empty);

            return(geographicCS);
        }
        /// <summary>
        /// Returns a <see cref="AngularUnit"/> given a piece of WKT.
        /// </summary>
        /// <param name="tokenizer">WktStreamTokenizer that has the WKT.</param>
        /// <returns>An object that implements the IUnit interface.</returns>
        private static IAngularUnit ReadAngularUnit(WktStreamTokenizer tokenizer)
        {
            tokenizer.ReadToken("[");
            string unitName = tokenizer.ReadDoubleQuotedWord();

            tokenizer.ReadToken(",");
            tokenizer.NextToken();
            double unitsPerUnit  = tokenizer.GetNumericValue();
            string authority     = String.Empty;
            long   authorityCode = -1;

            tokenizer.NextToken();
            if (tokenizer.GetStringValue() == ",")
            {
                tokenizer.ReadAuthority(ref authority, ref authorityCode);
                tokenizer.ReadToken("]");
            }
            return(new AngularUnit(unitsPerUnit, unitName, authority, authorityCode, String.Empty, String.Empty, String.Empty));
        }
        /// <summary>
        ///
        /// </summary>
        /// <param name="tokenizer"></param>
        /// <returns></returns>
        private static IPrimeMeridian ReadPrimeMeridian(WktStreamTokenizer tokenizer)
        {
            //PRIMEM["Greenwich",0,AUTHORITY["EPSG","8901"]]
            tokenizer.ReadToken("[");
            string name = tokenizer.ReadDoubleQuotedWord();

            tokenizer.ReadToken(",");
            tokenizer.NextToken();
            double longitude = tokenizer.GetNumericValue();

            tokenizer.NextToken();
            string authority     = String.Empty;
            long   authorityCode = -1;

            if (tokenizer.GetStringValue() == ",")
            {
                tokenizer.ReadAuthority(ref authority, ref authorityCode);
                tokenizer.ReadToken("]");
            }
            // make an assumption about the Angular units - degrees.
            IPrimeMeridian primeMeridian = new PrimeMeridian(longitude, AngularUnit.Degrees, name, authority, authorityCode, String.Empty, String.Empty, String.Empty);

            return(primeMeridian);
        }
        /// <summary>
        /// Reads either 3, 6 or 7 parameter Bursa-Wolf values from TOWGS84 token
        /// </summary>
        /// <param name="tokenizer"></param>
        /// <returns></returns>
        private static Wgs84ConversionInfo ReadWGS84ConversionInfo(WktStreamTokenizer tokenizer)
        {
            //TOWGS84[0,0,0,0,0,0,0]
            tokenizer.ReadToken("[");
            Wgs84ConversionInfo info = new Wgs84ConversionInfo();

            tokenizer.NextToken();
            info.Dx = tokenizer.GetNumericValue();
            tokenizer.ReadToken(",");

            tokenizer.NextToken();
            info.Dy = tokenizer.GetNumericValue();
            tokenizer.ReadToken(",");

            tokenizer.NextToken();
            info.Dz = tokenizer.GetNumericValue();
            tokenizer.NextToken();
            if (tokenizer.GetStringValue() == ",")
            {
                tokenizer.NextToken();
                info.Ex = tokenizer.GetNumericValue();

                tokenizer.ReadToken(",");
                tokenizer.NextToken();
                info.Ey = tokenizer.GetNumericValue();

                tokenizer.ReadToken(",");
                tokenizer.NextToken();
                info.Ez = tokenizer.GetNumericValue();

                tokenizer.NextToken();
                if (tokenizer.GetStringValue() == ",")
                {
                    tokenizer.NextToken();
                    info.Ppm = tokenizer.GetNumericValue();
                }
            }
            if (tokenizer.GetStringValue() != "]")
            {
                tokenizer.ReadToken("]");
            }
            return(info);
        }
        /// <summary>
        ///
        /// </summary>
        /// <param name="tokenizer"></param>
        /// <returns></returns>
        private static IProjectedCoordinateSystem ReadProjectedCoordinateSystem(WktStreamTokenizer tokenizer)
        {
            /*PROJCS[
             *      "OSGB 1936 / British National Grid",
             *      GEOGCS[
             *              "OSGB 1936",
             *              DATUM[...]
             *              PRIMEM[...]
             *              AXIS["Geodetic latitude","NORTH"]
             *              AXIS["Geodetic longitude","EAST"]
             *              AUTHORITY["EPSG","4277"]
             *      ],
             *      PROJECTION["Transverse Mercator"],
             *      PARAMETER["latitude_of_natural_origin",49],
             *      PARAMETER["longitude_of_natural_origin",-2],
             *      PARAMETER["scale_factor_at_natural_origin",0.999601272],
             *      PARAMETER["false_easting",400000],
             *      PARAMETER["false_northing",-100000],
             *      AXIS["Easting","EAST"],
             *      AXIS["Northing","NORTH"],
             *      AUTHORITY["EPSG","27700"]
             * ]
             */
            tokenizer.ReadToken("[");
            string name = tokenizer.ReadDoubleQuotedWord();

            tokenizer.ReadToken(",");
            tokenizer.ReadToken("GEOGCS");
            IGeographicCoordinateSystem geographicCS = ReadGeographicCoordinateSystem(tokenizer);

            tokenizer.ReadToken(",");
            IProjection projection = ReadProjection(tokenizer);
            IUnit       unit       = ReadLinearUnit(tokenizer);

            string authority     = String.Empty;
            long   authorityCode = -1;

            tokenizer.NextToken();
            List <AxisInfo> axes = new List <AxisInfo>(2);

            if (tokenizer.GetStringValue() == ",")
            {
                tokenizer.NextToken();
                while (tokenizer.GetStringValue() == "AXIS")
                {
                    axes.Add(ReadAxis(tokenizer));
                    tokenizer.NextToken();
                }
                if (tokenizer.GetStringValue() == "AUTHORITY")
                {
                    tokenizer.ReadAuthority(ref authority, ref authorityCode);
                    tokenizer.ReadToken("]");
                }
            }
            //This is default axis values if not specified.
            if (axes.Count == 0)
            {
                axes.Add(new AxisInfo("X", AxisOrientationEnum.East));
                axes.Add(new AxisInfo("Y", AxisOrientationEnum.North));
            }
            IProjectedCoordinateSystem projectedCS = new ProjectedCoordinateSystem(geographicCS.HorizontalDatum, geographicCS, unit as LinearUnit, projection, axes, name, authority, authorityCode, String.Empty, String.Empty, String.Empty);

            return(projectedCS);
        }