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) );
}
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 );
}
