rename to viirs_scan_bytes

scripts/viirs_pkt_size.py → scripts/viirs_scan_bytes.py

 #!/usr/bin/env python
+"""
+Write a NetCDF file containing size in bytes of VIIRS scans.
+"""
 import os
 import numpy as np
 import netCDF4
@@ -49,7 +52,7 @@ def read_data_from_rdr(filepath):
 
 if __name__ == '__main__':
     import argparse
-    parser = argparse.ArgumentParser()
+    parser = argparse.ArgumentParser(description=__doc__)
     parser.add_argument('viirs_rdr')
     args = parser.parse_args()
     destpath = os.path.basename(args.viirs_rdr) + '.size.nc'