def METHOD_NAME(geom_file, meta):
    print('read height & incidenceAngle from file: '+geom_file)
    dem = readfile.read(geom_file, datasetName='height', print_msg=False)[0]
    inc_angle = readfile.read(geom_file, datasetName='incidenceAngle', print_msg=False)[0]
    dem *= 1.0/np.cos(inc_angle*np.pi/180.0)
    ref_y = int(meta['REF_Y'])
    ref_x = int(meta['REF_X'])
    dem -= dem[ref_y, ref_x]
    # Design matrix for elevation v.s. phase
    # dem = dem.flatten()
    return dem