[decoders] Grib1 Indexer and GDS info

• To: <decoders@xxxxxxxxxxxxxxxx>
• Subject: [decoders] Grib1 Indexer and GDS info
• From: "Bali, Pelin" <pb@xxxxxxxxxxxxxxxxxx>
• Date: Tue, 5 Aug 2008 10:59:21 -0400

Thanks in advance.

------------
rec 98:1554711:date 2008080400 TMP kpds5=11 kpds6=105 kpds7=2 levels=(0,2) 
grid=16 2 m above gnd 24hr fcst:
 TMP=Temp. [K]
 timerange 0 P1 24 P2 0 TimeU 1  nx 145 ny 73 GDS grid 0 num_in_ave 0 missing 0
 center 1 subcenter 0 process 45 Table 1 scan: WE:SN winds(N/S)
 latlon: lat  -90.000000 to 90.000000 by 2.500000  nxny 10585 long 0.000000 to 
360.000000 by 2.500000, (145 x 73) scan 64 mode 128 bdsgrid 1--


The following is how I use the grib indexer to get the grib data.

RandomAccessFile raf = new RandomAccessFile(filePath, "r");
Grib1Indexer indexer = new Grib1Indexer();
PrintStream ps = new PrintStream(indexPath);
indexer.writeFileIndex(raf, ps, false );

Index index = new Index();
boolean rc = index.open(indexPath);
ArrayList gribIndexRecords = index.getGribRecords();
ArrayList<GdsRecord> gdsRecords = index.getHorizCoordSys();
//
// Build a hashmap for the GDS keys.
//              
java.util.HashMap gdsMap = new java.util.HashMap();
                
for (int a = 0; a < gdsRecords.size(); a++) {
        GdsRecord gdsRecord = gdsRecords.get(a);
        gdsMap.put(gdsRecord.gdsKey, gdsRecord);
}
                
for (Iterator it = gribIndexRecords.iterator (); it.hasNext (); ) {
   zz++;
   GribRecord gribRecord = (GribRecord)it.next();
   if (gribRecord != null) {
        //
        //Select only temperature.
        //
        if (gribRecord.paramNumber == 11 ) {
            if (gribRecord.levelType1 == 105) {
                if (gribRecord.levelValue1 == 2.0) {
                    if (gribRecord.forecastTime == 24) {
                        Grib1Data grib1data = new Grib1Data(raf);
                        if (gdsMap.get(gribRecord.gdsKey) != null) {
                            GdsRecord gds = 
(GdsRecord)gdsMap.get(gribRecord.gdsKey);
                           System.out.println("Dx: " + gds.dx);
                           System.out.println("Dy: " + gds.dy);
                           System.out.println("Grid Shape Code: " + 
gds.grid_shape_code);
                           System.out.println("Grid Type: " + gds.grid_type);
                           System.out.println("La1: " + gds.La1);
                           System.out.println("LaD: " + gds.LaD);
                           System.out.println("Latin1: " + gds.latin1);
                           System.out.println("Latin2: " + gds.latin2);
                           System.out.println("Lo1: " + gds.Lo1);
                           System.out.println("LoV: " + gds.LoV);
                           System.out.println("Major Axis Earth " + 
gds.major_axis_earth);
                           System.out.println("Minor Axis Earth " + 
gds.minor_axis_earth);
                           System.out.println("Nx: " + gds.nx);
                           System.out.println("Ny: " + gds.ny);
                           System.out.println("Radius Spherical Earth: " + 
gds.radius_spherical_earth);
                           System.out.println("Resolution: " + gds.resolution);
                           System.out.println("Winds: " + gds.winds);
                        }
                        float[] arr = grib1data.getData(gribRecord.offset1, 
gribRecord.decimalScale, gribRecord.bmsExists);
                    } // hour 24
                } // 2m
           } //above ground
       } // end of temperature
   } // grib record is not null
} // end for

Sincerely,

Pelin Bali

WeatherPredict Consulting, Inc.
3200 Atlantic Avenue, Suite 114
Raleigh, NC 27604

Phone (Direct): 919-239-8833
Phone (Main)  : 919-876-3633
Fax           : 919-876-4469

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