Esempio n. 1
0
void GRIBDataset::SetGribMetaData(grib_MetaData* meta)
{
    nRasterXSize = meta->gds.Nx;
    nRasterYSize = meta->gds.Ny;

/* -------------------------------------------------------------------- */
/*      Image projection.                                               */
/* -------------------------------------------------------------------- */
    OGRSpatialReference oSRS;

    switch(meta->gds.projType)
    {
      case GS3_LATLON:
      case GS3_GAUSSIAN_LATLON:
          // No projection, only latlon system (geographic)
          break;
      case GS3_MERCATOR:
        oSRS.SetMercator(meta->gds.meshLat, meta->gds.orientLon,
                         1.0, 0.0, 0.0);
        break;
      case GS3_POLAR:
        oSRS.SetPS(meta->gds.meshLat, meta->gds.orientLon,
                   meta->gds.scaleLat1,
                   0.0, 0.0);
        break;
      case GS3_LAMBERT:
        oSRS.SetLCC(meta->gds.scaleLat1, meta->gds.scaleLat2,
                    0.0, meta->gds.orientLon,
                    0.0, 0.0); // set projection
        break;
			

      case GS3_ORTHOGRAPHIC:

        //oSRS.SetOrthographic(0.0, meta->gds.orientLon,
        //											meta->gds.lon2, meta->gds.lat2);
        //oSRS.SetGEOS(meta->gds.orientLon, meta->gds.stretchFactor, meta->gds.lon2, meta->gds.lat2);
        oSRS.SetGEOS(  0, 35785831, 0, 0 ); // hardcoded for now, I don't know yet how to parse the meta->gds section
        break;
      case GS3_EQUATOR_EQUIDIST:
        break;
      case GS3_AZIMUTH_RANGE:
        break;
    }

/* -------------------------------------------------------------------- */
/*      Earth model                                                     */
/* -------------------------------------------------------------------- */
    double a = meta->gds.majEarth * 1000.0; // in meters
    double b = meta->gds.minEarth * 1000.0;
    if( a == 0 && b == 0 )
    {
        a = 6377563.396;
        b = 6356256.910;
    }

    if (meta->gds.f_sphere)
    {
        oSRS.SetGeogCS( "Coordinate System imported from GRIB file",
                        NULL,
                        "Sphere",
                        a, 0.0 );
    }
    else
    {
        double fInv = a/(a-b);
        oSRS.SetGeogCS( "Coordinate System imported from GRIB file",
                        NULL,
                        "Spheroid imported from GRIB file",
                        a, fInv );
    }

    OGRSpatialReference oLL; // construct the "geographic" part of oSRS
    oLL.CopyGeogCSFrom( &oSRS );

    double rMinX;
    double rMaxY;
    double rPixelSizeX;
    double rPixelSizeY;
    if (meta->gds.projType == GS3_ORTHOGRAPHIC)
    {
        //rMinX = -meta->gds.Dx * (meta->gds.Nx / 2); // This is what should work, but it doesn't .. Dx seems to have an inverse relation with pixel size
        //rMaxY = meta->gds.Dy * (meta->gds.Ny / 2);
        const double geosExtentInMeters = 11137496.552; // hardcoded for now, assumption: GEOS projection, full disc (like MSG)
        rMinX = -(geosExtentInMeters / 2);
        rMaxY = geosExtentInMeters / 2;
        rPixelSizeX = geosExtentInMeters / meta->gds.Nx;
        rPixelSizeY = geosExtentInMeters / meta->gds.Ny;
    }
    else if( oSRS.IsProjected() )
    {
        rMinX = meta->gds.lon1; // longitude in degrees, to be transformed to meters (or degrees in case of latlon)
        rMaxY = meta->gds.lat1; // latitude in degrees, to be transformed to meters 
        OGRCoordinateTransformation *poTransformLLtoSRS = OGRCreateCoordinateTransformation( &(oLL), &(oSRS) );
        if ((poTransformLLtoSRS != NULL) && poTransformLLtoSRS->Transform( 1, &rMinX, &rMaxY )) // transform it to meters
        {
            if (meta->gds.scan == GRIB2BIT_2) // Y is minY, GDAL wants maxY
                rMaxY += (meta->gds.Ny - 1) * meta->gds.Dy; // -1 because we GDAL needs the coordinates of the centre of the pixel
            rPixelSizeX = meta->gds.Dx;
            rPixelSizeY = meta->gds.Dy;
        }
        else
        {
            rMinX = 0.0;
            rMaxY = 0.0;
            
            rPixelSizeX = 1.0;
            rPixelSizeY = -1.0;
            
            oSRS.Clear();

            CPLError( CE_Warning, CPLE_AppDefined,
                      "Unable to perform coordinate transformations, so the correct\n"
                      "projected geotransform could not be deduced from the lat/long\n"
                      "control points.  Defaulting to ungeoreferenced." );
        }
        delete poTransformLLtoSRS;
    }
    else
    {
        rMinX = meta->gds.lon1; // longitude in degrees, to be transformed to meters (or degrees in case of latlon)
        rMaxY = meta->gds.lat1; // latitude in degrees, to be transformed to meters 

        if (meta->gds.lat2 > rMaxY)
          rMaxY = meta->gds.lat2;
        rPixelSizeX = meta->gds.Dx;
        rPixelSizeY = meta->gds.Dy;
    }

    adfGeoTransform[0] = rMinX;
    adfGeoTransform[3] = rMaxY;
    adfGeoTransform[1] = rPixelSizeX;
    adfGeoTransform[5] = -rPixelSizeY;

    CPLFree( pszProjection );
    pszProjection = NULL;
    oSRS.exportToWkt( &(pszProjection) );
}
Esempio n. 2
0
GDALDataset *MSGNDataset::Open( GDALOpenInfo * poOpenInfo )

{
    open_mode_type open_mode = MODE_VISIR;
    GDALOpenInfo* open_info = poOpenInfo;

    if (!poOpenInfo->bStatOK) {
        if ( EQUALN(poOpenInfo->pszFilename, "HRV:", 4) ) {
            open_info = new GDALOpenInfo(&poOpenInfo->pszFilename[4], poOpenInfo->eAccess);
            open_mode = MODE_HRV;
        } else
        if ( EQUALN(poOpenInfo->pszFilename, "RAD:", 4 ) ) {
            open_info = new GDALOpenInfo(&poOpenInfo->pszFilename[4], poOpenInfo->eAccess);
            open_mode = MODE_RAD;
        }
    }

/* -------------------------------------------------------------------- */
/*      Before trying MSGNOpen() we first verify that there is at        */
/*      least one "\n#keyword" type signature in the first chunk of     */
/*      the file.                                                       */
/* -------------------------------------------------------------------- */
    if( open_info->fp == NULL || open_info->nHeaderBytes < 50 )
        return NULL;

    /* check if this is a "NATIVE" MSG format image */
    if( !EQUALN((char *)open_info->pabyHeader,
                "FormatName                  : NATIVE", 36) )
    {
        return NULL;
    }
    
/* -------------------------------------------------------------------- */
/*      Confirm the requested access is supported.                      */
/* -------------------------------------------------------------------- */
    if( poOpenInfo->eAccess == GA_Update )
    {
        CPLError( CE_Failure, CPLE_NotSupported, 
                  "The MSGN driver does not support update access to existing"
                  " datasets.\n" );
        return NULL;
    }
    
/* -------------------------------------------------------------------- */
/*      Create a corresponding GDALDataset.                             */
/* -------------------------------------------------------------------- */
    MSGNDataset        *poDS;

    poDS = new MSGNDataset();

    poDS->fp = open_info->fp;
    open_info->fp = NULL;

/* -------------------------------------------------------------------- */
/*      Read the header.                                                */
/* -------------------------------------------------------------------- */
    // first reset the file pointer, then hand over to the msg_reader_core
    VSIFSeek( poDS->fp, 0, SEEK_SET );

    poDS->msg_reader_core = new Msg_reader_core(poDS->fp);

    if (!poDS->msg_reader_core->get_open_success()) {
        delete poDS;
        return NULL;
    }

    poDS->nRasterXSize = poDS->msg_reader_core->get_columns();
    poDS->nRasterYSize = poDS->msg_reader_core->get_lines();

    if (open_mode == MODE_HRV) {
        poDS->nRasterXSize *= 3;
        poDS->nRasterYSize *= 3;
    }


/* -------------------------------------------------------------------- */
/*      Create band information objects.                                */
/* -------------------------------------------------------------------- */
    unsigned int i;
    unsigned int band_count = 1;
    unsigned int missing_band_count = 0;
    unsigned char* bands = poDS->msg_reader_core->get_band_map();
    unsigned char band_map[MSG_NUM_CHANNELS+1];   // map GDAL band numbers to MSG channels
    for (i=0; i < MSG_NUM_CHANNELS; i++) {
        if (bands[i]) {
            bool ok_to_add = false;
            switch (open_mode) {
                case MODE_VISIR:
                    ok_to_add = i < MSG_NUM_CHANNELS - 1;
                    break;
                case MODE_RAD:
                    ok_to_add = (i <= 2) || (Msg_reader_core::Blackbody_LUT[i+1].B != 0);
                    break;
                case MODE_HRV:
                    ok_to_add = i == MSG_NUM_CHANNELS - 1;
                    break;
            }
            if (ok_to_add) {
                poDS->SetBand( band_count, new MSGNRasterBand( poDS, band_count, open_mode, i+1, i+1 - missing_band_count));
                band_map[band_count] = i+1;
                band_count++;
            }
        } else {
            missing_band_count++;
        }
    }

    double pixel_gsd_x;
    double pixel_gsd_y;
    double origin_x;
    double origin_y;

    if (open_mode != MODE_HRV) {
        pixel_gsd_x = 1000 * poDS->msg_reader_core->get_col_dir_step();  // convert from km to m
        pixel_gsd_y = 1000 * poDS->msg_reader_core->get_line_dir_step(); // convert from km to m
        origin_x = -pixel_gsd_x * (-(Conversions::nlines / 2.0) + poDS->msg_reader_core->get_col_start());
        origin_y = -pixel_gsd_y * ((Conversions::nlines / 2.0) - poDS->msg_reader_core->get_line_start());
    } else {
        pixel_gsd_x = 1000 * poDS->msg_reader_core->get_col_dir_step() / 3.0;  // convert from km to m, approximate for HRV
        pixel_gsd_y = 1000 * poDS->msg_reader_core->get_line_dir_step() / 3.0; // convert from km to m, approximate for HRV
        origin_x = -pixel_gsd_x * (-(3*Conversions::nlines / 2.0) + 3*poDS->msg_reader_core->get_col_start());
        origin_y = -pixel_gsd_y * ((3*Conversions::nlines / 2.0) - 3*poDS->msg_reader_core->get_line_start());
    }

    poDS->adfGeoTransform[0] = origin_x;
    poDS->adfGeoTransform[1] = pixel_gsd_x;
    poDS->adfGeoTransform[2] = 0.0;

    poDS->adfGeoTransform[3] = origin_y;
    poDS->adfGeoTransform[4] = 0.0;
    poDS->adfGeoTransform[5] = -pixel_gsd_y;

    OGRSpatialReference oSRS;

    oSRS.SetProjCS("Geostationary projection (MSG)");
    oSRS.SetGEOS(  0, 35785831, 0, 0 );
    oSRS.SetGeogCS(
        "MSG Ellipsoid",
        "MSG_DATUM",
        "MSG_SPHEROID",
        Conversions::rpol * 1000.0,
        1 / ( 1 - Conversions::rpol/Conversions::req)
    );

    oSRS.exportToWkt( &(poDS->pszProjection) );

    CALIBRATION* cal = poDS->msg_reader_core->get_calibration_parameters();
    char tagname[30];
    char field[300];

    poDS->SetMetadataItem("Radiometric parameters format", "offset slope");
    for (i=1; i < band_count; i++) {
        sprintf(tagname, "ch%02d_cal", band_map[i]);
        sprintf(field, "%.12e %.12e", cal[band_map[i]-1].cal_offset, cal[band_map[i]-1].cal_slope);
        poDS->SetMetadataItem(tagname, field);
    }

    sprintf(field, "%04d%02d%02d/%02d:%02d",
        poDS->msg_reader_core->get_year(),
        poDS->msg_reader_core->get_month(),
        poDS->msg_reader_core->get_day(),
        poDS->msg_reader_core->get_hour(),
        poDS->msg_reader_core->get_minute()
    );
    poDS->SetMetadataItem("Date/Time", field);

    sprintf(field, "%d %d",
         poDS->msg_reader_core->get_line_start(),
         poDS->msg_reader_core->get_col_start()
    );
    poDS->SetMetadataItem("Origin", field);


    if (open_info != poOpenInfo) {
        delete open_info;
    }

    return( poDS );
}