class_docstr: L15 Data Header handler.
  
  Reference Document (EUM/MSG/ICD/105):
  MSG Level 1.5 Image Data Format Description
docstr: Get image description data.
code: def image_description(self):
      """Get image description data."""
      projection_description = [
          ("TypeOfProjection", np.uint8),
          ("LongitudeOfSSP", np.float32),
      ]
  
      reference_grid = [
          ("NumberOfLines", np.int32),
          ("NumberOfColumns", np.int32),
          ("LineDirGridStep", np.float32),
          ("ColumnDirGridStep", np.float32),
          ("GridOrigin", np.uint8),
      ]
  
      planned_coverage_vis_ir = [
          ("SouthernLinePlanned", np.int32),
          ("NorthernLinePlanned", np.int32),
          ("EasternColumnPlanned", np.int32),
          ("WesternColumnPlanned", np.int32),
      ]
  
      planned_coverage_hrv = [
          ("LowerSouthLinePlanned", np.int32),
          ("LowerNorthLinePlanned", np.int32),
          ("LowerEastColumnPlanned", np.int32),
          ("LowerWestColumnPlanned", np.int32),
          ("UpperSouthLinePlanned", np.int32),
          ("UpperNorthLinePlanned", np.int32),
          ("UpperEastColumnPlanned", np.int32),
          ("UpperWestColumnPlanned", np.int32),
      ]
  
      level_15_image_production = [
          ("ImageProcDirection", np.uint8),
          ("PixelGenDirection", np.uint8),
          ("PlannedChanProcessing", (np.uint8, 12)),
      ]
  
      record = [
          ("ProjectionDescription", projection_description),
          ("ReferenceGridVIS_IR", reference_grid),
          ("ReferenceGridHRV", reference_grid),
          ("PlannedCoverageVIS_IR", planned_coverage_vis_ir),
          ("PlannedCoverageHRV", planned_coverage_hrv),
          ("Level15ImageProduction", level_15_image_production),
      ]
  
      return record
  
imports: import numpy
  from satpy.readers.eum_base import time_cds, time_cds_expanded, time_cds_short
  from satpy.readers.seviri_base import HRV_NUM_COLUMNS, HRV_NUM_LINES, VISIR_NUM_COLUMNS, VISIR_NUM_LINES
label_desc: Use image node_id 5 for calling the L15DataHeaderRecord obj's underlying member method code with example usage: obj.image_description() and returns: record