cdm/src/main/java/ucar/unidata/geoloc/projection/sat/GEOSTransform.java
public double[] earthToFGF(double geographic_lon, double geographic_lat, double scale_x, double offset_x, double scale_y, double offset_y) {
    double[] xy = earthToSat(geographic_lon, geographic_lat);
    return SatToFGF(xy[0], xy[1], scale_x, offset_x, scale_y, offset_y);
  }
public double[] earthToFGF(double geographic_lon, double geographic_lat, double scale_x, double offset_x, double scale_y, double offset_y) {
    double[] xy = earthToSat(geographic_lon, geographic_lat);
    return SatToFGF(xy[0], xy[1], scale_x, offset_x, scale_y, offset_y);
  }
Transform Earth coordinates (lon,lat) to fractional FGF coordinates.

@param geographic_lon Longitude, units: degrees
@param geographic_lat Latitude, units: degrees
@param scale_x        scaleFactor from the x coordinate variable
@param offset_x       addOffset from the x coordinate variable
@param scale_y        scaleFactor from the y coordinate variable
@param offset_y       addOffset from the y coordinate variable
@return fractional fgf coordinates