Test case for AMSR-3

The script run_amsr3_bufrencode.sh exercises the AMSR-3 L1B and L1R BUFR encode functions in MWIPP.

Requirements:
 - environment variable MWIPP_INSTALL pointing to the MWIPP installation directory
 - ecCodes v2.45.0 or later (supporting BUFR tables v45)

The script creates all 6 variants, starting from netCDF (see Section 3.8 of the MWIPP User Manual v1.3):

1.	l1b.bufr 		L1B, all channels
2.	l1r.bufr 		L1R, all channels
3.	l1r_l1b.bufr 		L1R, all channels plus full resolution 89 GHz from the L1B
4.	l1b_AMSR2.bufr		L1B, heritage channels (AMSR-2 BUFR sequence)
5.	l1r_AMSR2.bufr		L1R, heritage channels (AMSR-2 BUFR sequence)
6.	l1r_l1b_AMSR2.bufr	L1R, heritage channels, plus full resolution 89 GHz from the L1B (AMSR-2 BUFR sequence)

Equivalent EUMETSAT products for 1 and 2 are also provided. There are only minor differences compared with the MWIPP
products.

Note that the BUFR sequence used by products 1, 2 and 3 is not yet formally released by WMO and not yet available in
ecCodes. Users should either modify the ecCodes tables (see instructions in the Appendix of the MWIPP user Manual) or set
the following environment variable:

  export ECCODES_DEFINITION_PATH=$MWIPP_INSTALL/definitions

This just adds the AMSR-3 defintions. If necessary, you may wish to further extend the ECCODES_DEFINITION_PATH by including
the default definitions, e.g.

  export ECCODES_DEFINITION_PATH=$MWIPP_INSTALL/definitions:[Your ecCodes installation]/share/eccodes/definitions

The script also attempts to create quick-look images of the L1B and L1R data, using aapp_BUFR_quicklook.py.
The python plotting script uses Cartopy: see https://cartopy.readthedocs.io/stable/.

You can plot any channel you wish by modifying the script, but we have chosen 165GHz as an illustration because if you
compare the generated images you can see that the geolocation is significantly in error for the L1B BUFR product (which only
has one set of lat/lon values, to be used for all the main channels). Hence the recommendation in the MWIPP User Manual to
use L1R where possible.
