class_docstr: Base class for reading JPSS VIIRS & ATMS SDR HDF5 Files.
docstr: Get start orbit number.
docstr_tok: ["Get","start","orbit","number","."]
code: def start_orbit_number(self):
      """Get start orbit number."""
      start_orbit_path = self._get_aggr_path(
          "start_orbit", "AggregateBeginningOrbitNumber"
      )
      return int(self[start_orbit_path])
  
imports: import logging
  from datetime import datetime, timedelta
  import dask.array
  import numpy
  import xarray
  from satpy.readers.hdf5_utils import HDF5FileHandler
label_desc: Use image node_id 5 for calling the JPSS_SDR_FileHandler obj's underlying member method code with example usage: obj.start_orbit_number() and returns: int