示例#1
0
        // *** constructors *******************************************************

        /// <summary> Constructs a <tt>Grib1IndicatorSection</tt> object from a byteBuffer.
        ///
        /// </summary>
        /// <param name="raf">RandomAccessFile with IndicatorSection content
        ///
        /// </param>
        /// <throws>  NotSupportedException  if raf contains no valid GRIB file </throws>
        /// <throws>  IOException </throws>
        //UPGRADE_TODO: Class 'java.io.RandomAccessFile' was converted to 'System.IO.FileStream' which has a different behavior. "ms-help://MS.VSCC.v80/dv_commoner/local/redirect.htm?index='!DefaultContextWindowIndex'&keyword='jlca1073_javaioRandomAccessFile'"
        public Grib1IndicatorSection(System.IO.FileStream raf)
        {
            long mark = raf.Position;

            //if Grib edition 1, get bytes for the gribLength
            int[] data = new int[3];
            for (int i = 0; i < 3; i++)
            {
                data[i] = raf.ReadByte();
            }
            //System.out.println( "data[]=" + data[0] +", "+ data[1]+", "+data[2] ) ;

            // edition of GRIB specification
            edition = raf.ReadByte();
            //System.out.println( "edition=" + edition ) ;
            if (edition == 1)
            {
                // length of GRIB record
                // Reset to beginning, then read 3 bytes
                raf.Position = mark;
                gribLength   = (long)GribNumbers.uint3(raf);
                // Skip next byte, edition already read
                raf.ReadByte();
                //System.out.println( "edition 1 gribLength=" + gribLength ) ;
                length = 8;
            }
            else if (edition == 2)
            {
                // length of GRIB record
                discipline = data[2];
                //System.out.println( "discipline=" + discipline) ;
                gribLength = GribNumbers.int8(raf);
                //System.out.println( "editon 2 gribLength=" + gribLength) ;
                length = 16;
            }
            else
            {
                throw new NotSupportedException("GRIB edition " + edition + " is not yet supported");
            }
        }         // end Grib1IndicatorSection
示例#2
0
        /// <summary> Constructs a <tt> Grib1BitMapSection</tt> object from a raf input stream.
        ///
        /// </summary>
        /// <param name="raf">input stream with BMS content
        ///
        /// </param>
        //UPGRADE_TODO: Class 'java.io.RandomAccessFile' was converted to 'System.IO.FileStream' which has a different behavior. "ms-help://MS.VSCC.v80/dv_commoner/local/redirect.htm?index='!DefaultContextWindowIndex'&keyword='jlca1073_javaioRandomAccessFile'"
        internal Grib1BitMapSection(System.IO.Stream raf)
        {
            int[] bitmask = new int[] { 128, 64, 32, 16, 8, 4, 2, 1 };

            // octet 1-3 (length of section)
            length = (int)GribNumbers.uint3(raf);


            // octet 4 unused bits
            int unused = raf.ReadByte();


            // octets 5-6
            int bm = GribNumbers.int2(raf);

            if (bm != 0)
            {
                System.Console.Out.WriteLine("BMS pre-defined BM provided by center");
                if ((length - 6) == 0)
                {
                    return;
                }
                sbyte[] data = new sbyte[length - 6];
                SupportClass.ReadInput(raf, data, 0, data.Length);
                return;
            }

            sbyte[] data2 = new sbyte[length - 6];
            SupportClass.ReadInput(raf, data2, 0, data2.Length);

            // create new bit map, octet 4 contains number of unused bits at the end
            Bitmap = new bool[(length - 6) * 8 - unused];


            // fill bit map
            for (int i = 0; i < Bitmap.Length; i++)
            {
                Bitmap[i] = (data2[i / 8] & bitmask[i % 8]) != 0;
            }
        } // end Grib1BitMapSection
示例#3
0
文件: Grib1Input.cs 项目: baks/GribCS
        /// <summary> scans a Grib file to gather information that could be used to
        /// create an index or dump the metadata contents.
        ///
        /// </summary>
        /// <param name="getProducts">products have enough information for data extractions
        /// </param>
        /// <param name="oneRecord">returns after processing one record in the Grib file
        /// </param>
        /// <throws>  NotSupportedException </throws>
        public void  scan(bool getProducts, bool oneRecord)
        {
            long start = (System.DateTime.Now.Ticks - 621355968000000000) / 10000;

            // stores the number of times a particular GDS is used
            //UPGRADE_TODO: Class 'java.util.HashMap' was converted to 'System.Collections.Hashtable' which has a different behavior. "ms-help://MS.VSCC.v80/dv_commoner/local/redirect.htm?index='!DefaultContextWindowIndex'&keyword='jlca1073_javautilHashMap'"
            System.Collections.Hashtable  gdsCounter = new System.Collections.Hashtable();
            Grib1ProductDefinitionSection pds        = null;
            Grib1GridDefinitionSection    gds        = null;
            long startOffset = -1;

            //System.out.println("file position =" + raf.Position);
            while (raf.Position < raf.Length)
            {
                if (seekHeader(raf, raf.Length, out startOffset))
                {
                    // Read Section 0 Indicator Section
                    Grib1IndicatorSection is_Renamed = new Grib1IndicatorSection(raf);
                    //System.out.println( "Grib record length=" + is.getGribLength());
                    // EOR (EndOfRecord) calculated so skipping data sections is faster
                    long EOR = raf.Position + is_Renamed.GribLength - is_Renamed.Length;

                    // Read Section 1 Product Definition Section PDS
                    pds = new Grib1ProductDefinitionSection(raf);
                    if (pds.LengthErr)
                    {
                        continue;
                    }

                    if (pds.gdsExists())
                    {
                        // Read Section 2 Grid Definition Section GDS
                        gds = new Grib1GridDefinitionSection(raf);
                    }
                    else
                    {
                        // GDS doesn't exist so make one
                        //System.out.println("GribRecord: No GDS included.");
                        //System.out.println("Process ID:" + pds.getProcess_Id() );
                        //System.out.println("Grid ID:" + pds.getGrid_Id() );
                        gds = (Grib1GridDefinitionSection) new Grib1Grid(pds);
                    }
                    // obtain BMS or BDS offset in the file for this product
                    long dataOffset = 0;
                    if (pds.Center == 98)
                    {
                        // check for ecmwf offset by 1 bug
                        int length = (int)GribNumbers.uint3(raf);                         // should be length of BMS
                        if ((length + raf.Position) < EOR)
                        {
                            dataOffset = raf.Position - 3;                             // ok
                        }
                        else
                        {
                            dataOffset = raf.Position - 2;
                        }
                    }
                    else
                    {
                        dataOffset = raf.Position;
                    }
                    // position filePointer to EndOfRecord
                    raf.Seek(EOR, System.IO.SeekOrigin.Begin);
                    //System.out.println("file offset = " + raf.Position);

                    // assume scan ok
                    if (getProducts)
                    {
                        Grib1Product gp = new Grib1Product(header, pds, getGDSkey(gds, gdsCounter), dataOffset, raf.Position);
                        products.Add(gp);
                    }
                    else
                    {
                        Grib1Record gr = new Grib1Record(header, is_Renamed, pds, gds, dataOffset, raf.Position, startOffset);
                        records.Add(gr);
                    }
                    if (oneRecord)
                    {
                        return;
                    }

                    // early return because ending "7777" missing
                    if (raf.Position > raf.Length)
                    {
                        raf.Seek(0, System.IO.SeekOrigin.Begin);
                        System.Console.Error.WriteLine("Grib1Input: possible file corruption");
                        checkGDSkeys(gds, gdsCounter);
                        return;
                    }
                }         // end if seekHeader
                          //System.out.println( "raf.Position=" + raf.Position);
                          //System.out.println( "raf.Length=" + raf.Length );
            }             // end while raf.Position < raf.Length
            //System.out.println("GribInput: processed in " +
            //   (System.currentTimeMillis()- start) + " milliseconds");
            checkGDSkeys(gds, gdsCounter);
            return;
        }         // end scan
示例#4
0
        // *** constructors *******************************************************

        /// <summary> Constructs a <tt>Grib1ProductDefinitionSection</tt> object from a raf.
        ///
        /// </summary>
        /// <param name="raf">with PDS content
        ///
        /// </param>
        /// <throws>  NotSupportedException  if raf contains no valid GRIB file </throws>
        //UPGRADE_TODO: Class 'java.io.RandomAccessFile' was converted to 'System.IO.FileStream' which has a different behavior. "ms-help://MS.VSCC.v80/dv_commoner/local/redirect.htm?index='!DefaultContextWindowIndex'&keyword='jlca1073_javaioRandomAccessFile'"
        public Grib1ProductDefinitionSection(System.IO.FileStream raf)
        {
            // octets 1-3 PDS length
            length = (int)GribNumbers.uint3(raf);
            //System.out.println( "PDS length = " + length );

            // Paramter table octet 4
            table_version = raf.ReadByte();

            // Center  octet 5
            center_id = raf.ReadByte();

            // octet 6 Generating Process - See Table A
            process_id = raf.ReadByte();

            // octet 7 (id of grid type) - not supported yet
            grid_id = raf.ReadByte();

            //octet 8 (flag for presence of GDS and BMS)
            int exists = raf.ReadByte();

            //BKSystem.IO.BitStream s = new BKSystem.IO.BitStream(8);
//            s.WriteByte((byte)raf.ReadByte());
//            s.Position = 0;
//            sbyte exists;
//            s.Read(out exists);
//            bms_exists = (exists & 64) == 64;

            gds_exists = (exists & 128) == 128;
            bms_exists = (exists & 64) == 64;

            // octet 9 (parameter and unit)
            parameterNumber = raf.ReadByte();

            // octets 10-12 (level)
            int levelType   = raf.ReadByte();
            int levelValue1 = raf.ReadByte();
            int levelValue2 = raf.ReadByte();

            level = new GribPDSLevel(levelType, levelValue1, levelValue2);

            // octets 13-17 (base time for reference time)
            int year   = raf.ReadByte();
            int month  = raf.ReadByte();
            int day    = raf.ReadByte();
            int hour   = raf.ReadByte();
            int minute = raf.ReadByte();

            // get info for forecast time
            // octet 18 Forecast time unit
            timeUnit = raf.ReadByte();

            switch (timeUnit)
            {
            case 0:                      // minute
                tUnit = "minute";
                break;

            case 1:                      // hours
                tUnit = "hour";
                break;

            case 2:                      // day
                tUnit = "day";
                break;

            case 3:                      // month
                tUnit = "month";
                break;

            case 4:                      //1 year
                tUnit = "1year";
                break;

            case 5:                      // decade
                tUnit = "decade";
                break;

            case 6:                      // normal
                tUnit = "day";
                break;

            case 7:                      // century
                tUnit = "century";
                break;

            case 10:                      //3 hours
                tUnit = "3hours";
                break;

            case 11:                      // 6 hours
                tUnit = "6hours";
                break;

            case 12:                      // 12 hours
                tUnit = "12hours";
                break;

            case 254:                      // second
                tUnit = "second";
                break;


            default:
                System.Console.Error.WriteLine("PDS: Time Unit " + timeUnit + " is not yet supported");
                break;
            }

            // octet 19 & 20 used to create Forecast time
            p1 = raf.ReadByte();
            p2 = raf.ReadByte();

            // octet 21 (time range indicator)
            timeRangeValue = raf.ReadByte();
            // forecast time is always at the end of the range
            //System.out.println( "PDS timeRangeValue =" + timeRangeValue );
            switch (timeRangeValue)
            {
            case 0:
                timeRange    = "product valid at RT + P1";
                forecastTime = p1;
                break;

            case 1:
                timeRange    = "product valid for RT, P1=0";
                forecastTime = 0;
                break;

            case 2:
                timeRange    = "product valid from (RT + P1) to (RT + P2)";
                forecastTime = p2;
                break;

            case 3:
                timeRange    = "product is an average between (RT + P1) to (RT + P2)";
                forecastTime = p2;
                break;

            case 4:
                timeRange    = "product is an accumulation between (RT + P1) to (RT + P2)";
                forecastTime = p2;
                break;

            case 5:
                timeRange    = "product is the difference (RT + P2) - (RT + P1)";
                forecastTime = p2;
                break;

            case 6:
                timeRange    = "product is an average from (RT - P1) to (RT - P2)";
                forecastTime = -p2;
                break;

            case 7:
                timeRange    = "product is an average from (RT - P1) to (RT + P2)";
                forecastTime = p2;
                break;

            case 10:
                timeRange = "product valid at RT + P1";
                // p1 really consists of 2 bytes p1 and p2
                forecastTime = p1 = GribNumbers.int2(p1, p2);
                p2           = 0;
                break;

            case 51:
                timeRange    = "mean value from RT to (RT + P2)";
                forecastTime = p2;
                break;

            default:
                System.Console.Error.WriteLine("PDS: Time Range Indicator " + timeRangeValue + " is not yet supported");
                break;
            }

            // octet 22 & 23
            int avgInclude = GribNumbers.int2(raf);

            // octet 24
            int avgMissing = raf.ReadByte();

            // octet 25
            int century = raf.ReadByte() - 1;

            // octet 26, sub center
            subcenter_id = raf.ReadByte();

            // octets 27-28 (decimal scale factor)
            decscale = GribNumbers.int2(raf);

            refTime       = new DateTime(century * 100 + year, month, day, hour, minute, 0, DateTimeKind.Utc);
            baseTime      = refTime;
            referenceTime = refTime.ToString(dateFormat);

            //System.out.println( "PDS referenceTime raw = " +
            //(century * 100 + year) +"-" +
            //month + "-" + day + "T" + hour +":" + minute +":00Z" );
            //System.out.println( "PDS referenceTime     = " + referenceTime );

            // TODO

            /*
             *          parameter_table = GribPDSParamTable.getParameterTable(center_id, subcenter_id, table_version);
             *          parameter = parameter_table.getParameter(parameterNumber);
             */
            parameter = new Parameter();


            if (center_id == 7 && subcenter_id == 2)
            {
                // ensemble product
                epds = new Grib1Ensemble(raf, parameterNumber);
            }
            // Special handling of 2D Wave Spectra (single)
            else if (table_version == 140 && parameterNumber == 251)
            {
                SupportClass.Skip(raf, 12);
                int extDef = raf.ReadByte(); // Extension definition

                // Read ECMWF extension for 2D wave spectra single
                if (extDef == 13)
                {
                    waveSpectra2DDirFreq = new Grib1WaveSpectra2DDirFreq(raf);
                }
            }
            else if (length != 28)
            {
                // check if all bytes read in section
                //lengthErr = true;
                int extra;
                for (int i = 29; i <= length; i++)
                {
                    extra = raf.ReadByte();
                }
            }
        }         // end Grib1ProductDefinitionSection
示例#5
0
        /// <summary> Constructs a Grib1BinaryDataSection object from a raf.
        /// A bit map is defined.
        ///
        /// </summary>
        /// <param name="raf">raf with BDS content
        /// </param>
        /// <param name="decimalscale">the exponent of the decimal scale
        /// </param>
        /// <param name="bms">bit map section of GRIB record
        ///
        /// </param>
        /// <throws>  NotSupportedException  if stream contains no valid GRIB file </throws>
        //UPGRADE_TODO: Class 'java.io.RandomAccessFile' was converted to 'System.IO.FileStream' which has a different behavior. "ms-help://MS.VSCC.v80/dv_commoner/local/redirect.htm?index='!DefaultContextWindowIndex'&keyword='jlca1073_javaioRandomAccessFile'"
        public Grib1BinaryDataSection(System.IO.FileStream raf, int decimalscale, Grib1BitMapSection bms)
        {
            // octets 1-3 (section length)
            length = (int)GribNumbers.uint3(raf);
            //System.out.println( "BDS length = " + length );

            // octet 4, 1st half (packing flag)
            int unusedbits = raf.ReadByte();

            // TODO Check this!!!
            if ((unusedbits & 192) != 0)
            {
                throw new NotSupportedException("BDS: (octet 4, 1st half) not grid point data and simple packing ");
            }

            // octet 4, 2nd half (number of unused bits at end of this section)
            unusedbits = unusedbits & 15;
            //System.out.println( "BDS unusedbits = " + unusedbits );

            // octets 5-6 (binary scale factor)
            int binscale = GribNumbers.int2(raf);

            // octets 7-10 (reference point = minimum value)
            float refvalue = GribNumbers.float4(raf);

            // octet 11 (number of bits per value)
            int numbits = raf.ReadByte();

            //System.out.println( "BDS numbits = " + numbits );
            if (numbits == 0)
            {
                isConstant = true;
            }
            //System.out.println( "BDS isConstant = " + isConstant );

            // *** read values *******************************************************

            //UPGRADE_WARNING: Data types in Visual C# might be different.  Verify the accuracy of narrowing conversions. "ms-help://MS.VSCC.v80/dv_commoner/local/redirect.htm?index='!DefaultContextWindowIndex'&keyword='jlca1042'"
            float ref_Renamed = (float)(System.Math.Pow(10.0, -decimalscale) * refvalue);
            //UPGRADE_WARNING: Data types in Visual C# might be different.  Verify the accuracy of narrowing conversions. "ms-help://MS.VSCC.v80/dv_commoner/local/redirect.htm?index='!DefaultContextWindowIndex'&keyword='jlca1042'"
            float scale = (float)(System.Math.Pow(10.0, -decimalscale) * System.Math.Pow(2.0, binscale));

            if (bms != null)
            {
                bool[] bitmap = bms.Bitmap;

                values = new float[bitmap.Length];
                for (int i = 0; i < bitmap.Length; i++)
                {
                    if (bitmap[i])
                    {
                        if (!isConstant)
                        {
                            values[i] = ref_Renamed + scale * bits2UInt(numbits, raf);
                        }
                        else
                        {
                            // rdg - added this to handle a constant valued parameter
                            values[i] = ref_Renamed;
                        }
                    }
                    else
                    {
                        values[i] = Grib1BinaryDataSection.UNDEFINED;
                    }
                }
            }
            else
            {
                // bms is null
                if (!isConstant)
                {
                    //System.out.println( "BDS values.size = " +
                    //(((length - 11) * 8 - unusedbits) /  numbits));
                    values = new float[((length - 11) * 8 - unusedbits) / numbits];

                    for (int i = 0; i < values.Length; i++)
                    {
                        values[i] = ref_Renamed + scale * bits2UInt(numbits, raf);
                    }
                }
                else
                {
                    // constant valued - same min and max
                    int x = 0, y = 0;
                    raf.Seek(raf.Position - 53, System.IO.SeekOrigin.Begin);                     // return to start of GDS
                    length = (int)GribNumbers.uint3(raf);
                    if (length == 42)
                    {
                        // Lambert/Mercator offset
                        SupportClass.Skip(raf, 3);
                        x = GribNumbers.int2(raf);
                        y = GribNumbers.int2(raf);
                    }
                    else
                    {
                        SupportClass.Skip(raf, 7);
                        length = (int)GribNumbers.uint3(raf);
                        if (length == 32)
                        {
                            // Polar sterographic
                            SupportClass.Skip(raf, 3);
                            x = GribNumbers.int2(raf);
                            y = GribNumbers.int2(raf);
                        }
                        else
                        {
                            x = y = 1;
                            System.Console.Out.WriteLine("BDS constant value, can't determine array size");
                        }
                    }
                    values = new float[x * y];
                    for (int i = 0; i < values.Length; i++)
                    {
                        values[i] = ref_Renamed;
                    }
                }
            }
        }         // end Grib1BinaryDataSection
示例#6
0
        /// <summary> Constructs a <tt>Grib1GridDefinitionSection</tt> object from a raf.
        ///
        /// </summary>
        /// <param name="raf">RandomAccessFile with GDS content
        ///
        /// </param>
        /// <throws>  NoValidGribException  if raf contains no valid GRIB info </throws>
        //UPGRADE_TODO: Class 'java.io.RandomAccessFile' was converted to 'System.IO.FileStream' which has a different behavior. "ms-help://MS.VSCC.v80/dv_commoner/local/redirect.htm?index='!DefaultContextWindowIndex'&keyword='jlca1073_javaioRandomAccessFile'"
        public Grib1GridDefinitionSection(System.IO.FileStream raf)
        {
            int reserved;             // used to read empty space

            // octets 1-3 (Length of GDS)
            length = (int)GribNumbers.uint3(raf);
            if (length == 0)
            {
                // there's a extra byte between PDS and GDS
                SupportClass.Skip(raf, -2);
                length = (int)GribNumbers.uint3(raf);
            }
            //System.out.println( "GDS length = " + length );

            // TODO Fix Checksum stuff
            // get byte array for this gds, then reset raf to same position
            // calculate checksum for this gds via the byte array

            /*
             * long mark = raf.Position;
             * sbyte[] dst = new sbyte[length - 3];
             * SupportClass.ReadInput(raf, dst, 0, dst.Length);
             * raf.Seek(mark, System.IO.SeekOrigin.Begin);
             * //UPGRADE_ISSUE: Class 'java.util.zip.CRC32' was not converted. "ms-help://MS.VSCC.v80/dv_commoner/local/redirect.htm?index='!DefaultContextWindowIndex'&keyword='jlca1000_javautilzipCRC32'"
             * //UPGRADE_ISSUE: Constructor 'java.util.zip.CRC32.CRC32' was not converted. "ms-help://MS.VSCC.v80/dv_commoner/local/redirect.htm?index='!DefaultContextWindowIndex'&keyword='jlca1000_javautilzipCRC32'"
             * CRC32 cs = new CRC32();
             * //UPGRADE_ISSUE: Method 'java.util.zip.CRC32.update' was not converted. "ms-help://MS.VSCC.v80/dv_commoner/local/redirect.htm?index='!DefaultContextWindowIndex'&keyword='jlca1000_javautilzipCRC32'"
             * cs.update(dst);
             * //UPGRADE_ISSUE: Method 'java.util.zip.CRC32.getValue' was not converted. "ms-help://MS.VSCC.v80/dv_commoner/local/redirect.htm?index='!DefaultContextWindowIndex'&keyword='jlca1000_javautilzipCRC32'"
             * checksum = System.Convert.ToString(cs.getValue());
             * //System.out.println( "GDS checksum =" + checksum );
             */

            // octets 4 NV
            int NV = raf.ReadByte();

            //System.out.println( "GDS NV = " + NV );

            // octet 5 PL the location (octet number) of the list of numbers of points in each row
            P_VorL = raf.ReadByte();
            //System.out.println( "GDS PL = " + P_VorL );

            // octet 6 (grid type)
            type = raf.ReadByte();
            //System.out.println( "GDS grid type = " + type );
            name = getName(type);

            if (type != 50)
            {
                // values same up to resolution

                // octets 7-8 (Nx - number of points along x-axis)
                nx = GribNumbers.int2(raf);
                nx = (nx == -1)?1:nx;

                // octets 9-10 (Ny - number of points along y-axis)
                ny = GribNumbers.int2(raf);
                ny = (ny == -1)?1:ny;

                // octets 11-13 (La1 - latitude of first grid point)
                lat1 = GribNumbers.int3(raf) / 1000.0;

                // octets 14-16 (Lo1 - longitude of first grid point)
                lon1 = GribNumbers.int3(raf) / 1000.0;

                // octet 17 (resolution and component flags).  See Table 7
                resolution = raf.ReadByte();
            }

            switch (type)
            {
            //  Latitude/Longitude  grids ,  Arakawa semi-staggered e-grid rotated
            //  Arakawa filled e-grid rotated
            case 0:
            case 4:
            case 40:
            case 201:
            case 202:

                // octets 18-20 (La2 - latitude of last grid point)
                lat2 = GribNumbers.int3(raf) / 1000.0;

                // octets 21-23 (Lo2 - longitude of last grid point)
                lon2 = GribNumbers.int3(raf) / 1000.0;

                // octets 24-25 (Dx - Longitudinal Direction Increment )
                dx = GribNumbers.int2(raf) / 1000.0;

                // octets 26-27 (Dy - Latitudinal Direction Increment )
                //               Np - parallels between a pole and the equator
                if (type == 4)
                {
                    np = GribNumbers.int2(raf);
                }
                else
                {
                    dy = GribNumbers.int2(raf) / 1000.0;
                }

                // octet 28 (Scanning mode)  See Table 8
                scan = raf.ReadByte();

                // octet 29-32 reserved
                reserved = GribNumbers.int4(raf);

                if (length > 32)
                {
                    // getP_VorL(raf);
                    // Vertical coordinates (NV) and thinned grids (PL) not supported - skip this
                    SupportClass.Skip(raf, length - 32);
                }

                break;                         // end Latitude/Longitude grids


            case 1:                      //  Mercator grids

                // octets 18-20 (La2 - latitude of last grid point)
                lat2 = GribNumbers.int3(raf) / 1000.0;

                // octets 21-23 (Lo2 - longitude of last grid point)
                lon2 = GribNumbers.int3(raf) / 1000.0;

                // octets 24-26 (Latin - latitude where cylinder intersects the earth
                latin1 = GribNumbers.int3(raf) / 1000.0;

                // octet 27 reserved
                reserved = raf.ReadByte();

                // octet 28 (Scanning mode)  See Table 8
                scan = raf.ReadByte();

                // octets 29-31 (Dx - Longitudinal Direction Increment )
                dx = GribNumbers.int3(raf);

                // octets 32-34 (Dx - Longitudinal Direction Increment )
                dy = GribNumbers.int3(raf);

                // octet 35-42 reserved
                reserved = GribNumbers.int4(raf);
                reserved = GribNumbers.int4(raf);

                if (length > 42)
                {
                    // getP_VorL(raf);
                    // Vertical coordinates (NV) and thinned grids (PL) not supported - skip this
                    SupportClass.Skip(raf, length - 42);
                }

                break;                         // end Mercator grids


            case 3:                      // Lambert Conformal

                // octets 18-20 (Lov - Orientation of the grid - east lon parallel to y axis)
                lov = GribNumbers.int3(raf) / 1000.0;

                // octets 21-23 (Dx - the X-direction grid length) See Note 2 of Table D
                dx = GribNumbers.int3(raf);

                // octets 24-26 (Dy - the Y-direction grid length) See Note 2 of Table D
                dy = GribNumbers.int3(raf);

                // octets 27 (Projection Center flag) See Note 5 of Table D
                proj_center = raf.ReadByte();

                // octet 28 (Scanning mode)  See Table 8
                scan = raf.ReadByte();

                // octets 29-31 (Latin1 - first lat where secant cone cuts spherical earth
                latin1 = GribNumbers.int3(raf) / 1000.0;

                // octets 32-34 (Latin2 - second lat where secant cone cuts spherical earth)
                latin2 = GribNumbers.int3(raf) / 1000.0;

                // octets 35-37 (lat of southern pole)
                latsp = GribNumbers.int3(raf) / 1000.0;

                // octets 38-40 (lon of southern pole)
                lonsp = GribNumbers.int3(raf) / 1000.0;

                // octets 41-42
                reserved = GribNumbers.int2(raf);

                if (length > 42)
                {
                    // getP_VorL(raf);
                    // Vertical coordinates (NV) and thinned grids (PL) not supported - skip this
                    SupportClass.Skip(raf, length - 42);
                }

                break;                         // end Lambert Conformal


            case 5:                      //  Polar Stereographic grids

                // octets 18-20 (Lov - Orientation of the grid - east lon parallel to y axis)
                lov = GribNumbers.int3(raf) / 1000.0;

                // octets 21-23 (Dx - Longitudinal Direction Increment )
                dx = GribNumbers.int3(raf);

                // octets 24-26(Dy - Latitudinal Direction Increment )
                dy = GribNumbers.int3(raf);

                // octets 27 (Projection Center flag) See Note 5 of Table D
                proj_center = raf.ReadByte();

                // octet 28 (Scanning mode)  See Table 8
                scan = raf.ReadByte();

                // octet 29-32 reserved
                reserved = GribNumbers.int4(raf);

                if (length > 32)
                {
                    // getP_VorL(raf);
                    // Vertical coordinates (NV) and thinned grids (PL) not supported - skip this
                    SupportClass.Skip(raf, length - 32);
                }

                break;                         // end Polar Stereographic grids

            //rotated grid
            case 10:
                //18-20
                this.lat2 = GribNumbers.int3(raf) / 1000.0;
                //21-23
                this.lon2 = GribNumbers.int3(raf) / 1000.0;

                //24-25
                var tmpDx = GribNumbers.int2(raf);
                this.dx = tmpDx == -1 ? -9999.0 : tmpDx / 1000.0;

                //26-27
                var tmpDy = GribNumbers.int2(raf);
                this.dy = tmpDy == -1 ? -9999.0 : tmpDy / 1000.0;

                //28
                scan = raf.ReadByte();
                //29-32
                GribNumbers.int4(raf);

                //33-35
                this.latsp = GribNumbers.int3(raf) / 1000.0;
                //36-38
                this.lonsp = GribNumbers.int3(raf) / 1000.0;

                //39-42 - angle
                GribNumbers.float4(raf);

                if (length > 42)
                {
                    SupportClass.Skip(raf, length - 42);
                }

                break;


            default:
                System.Console.Out.WriteLine("Unknown Grid Type : " + type);
                break;
            }             // end switch grid_type

            //System.out.println( "scan=" + scan );
            if ((scan & 63) != 0)
            {
                throw new NoValidGribException("GDS: This scanning mode (" + scan + ") is not supported.");
            }
        }         // end Grib1GridDefinitionSection( raf )