emeta_api.c

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#include "emeta_api.h"              /* EMETA structure and routines   */
 
static EMETA        emeta;      /* Enhanced metadata structure    */
 
int emeta_init(             /* Returns num bands in EMETA     */
    char    *emeta_filename )   /* Enhanced metadata file name    */
{
    /* Read the enhanced metadata file */
    if ( emeta_read( &emeta, emeta_filename ) != SUCCESS )
    {
        IAS_LOG_ERROR("Reading the enhanced metadata file %s.", emeta_filename);
        return(0);
    }
 
    return(emeta.num_band);
}
 
int emeta_get_frame(
    int         eband,          /* Input band index        */
    EMETA_FRAME *frame )        /* Output image frame info */
{
 
    if ( eband > emeta.num_band-1 )
    {
        IAS_LOG_ERROR("Invalid band requested");
        return(ERROR);
    }
 
    /* Establish the output image file frame */
    frame->band = emeta.band_emeta[eband].band;
    frame->nlines = emeta.band_emeta[eband].l1t_lines;
    frame->nsamps = emeta.band_emeta[eband].l1t_samps;
    frame->code = emeta.projection.code;
    frame->zone = emeta.projection.zone;
    frame->pixsize = emeta.band_emeta[eband].pixsize;
    frame->ul_x = emeta.projection.corners.upleft.x;
    frame->ul_y = emeta.projection.corners.upleft.y;
 
    return(SUCCESS);
}
 
int emeta_calc(
    int     in_line,        /* L1T line coordinate              */
    int     in_samp,        /* L1T sample coordinate            */
    int     in_band,        /* Spectral band number             */
    short   *sat_zn,        /* Satellite zenith angle           */
    short   *sat_az,        /* Satellite azimuth angle          */
    short   *sun_zn,        /* Solar zenith angle               */
    short   *sun_az )       /* Solar azimuth angle              */
{
    double  l1t_line;       /* Float line coordinate            */
    double  l1t_samp;       /* Float sample coordinate          */
    double  satang[2];      /* Satellite viewing angles         */
    double  sunang[2];      /* Solar viewing angles             */
    double  r2d;            /* Radian to degree conversion      */
    int     eband;          /* Band index                       */
    int     band;           /* Band number                      */
    int     status;         /* Status return flag               */
 
    /* Initialize conversion factor from radians to hundredths of degrees */
    r2d = 4500.0 / atan(1.0);
    status = ERROR;
 
    /* Process the angles for each band */
    for ( eband=0; eband<emeta.num_band; eband++ )
    {
        band = emeta.band_emeta[eband].band;
        if ( band != in_band ) continue;
        status = SUCCESS;
 
        /* Calculate the angles for the current line/sample */
        l1t_line = (double)in_line;
        l1t_samp = (double)in_samp;
 
    /* Calculate the viewing geometry using the RPC method */
        status = emeta_angles_rpc( l1t_line, l1t_samp, &emeta, band, satang, sunang );
        if ( status != SUCCESS ) IAS_LOG_ERROR("Evaluating angles in band %d.", band);
 
        /* Quantize the satellite angles */
        *sat_zn = (short)floor( r2d*satang[0] + 0.5 );
        *sat_az = (short)floor( r2d*satang[1] + 0.5 );
        /* Quantize the solar angles */
        *sun_zn = (short)floor( r2d*sunang[0] + 0.5 );
        *sun_az = (short)floor( r2d*sunang[1] + 0.5 );
    }
 
    /* Return status */
    return( status );
}
 
void emeta_close()
{
    /* Free the ephemeris structure */
    emeta_free_ephemeris( &emeta );
 
    return;
}