README.macOS

==============================================
!
!	HOW TO BUILD CRTM_coef on macOS
!
==============================================


Requirements:
=============
Before attempting to build CRTM_coef, please
ensure that the following dependencies are 
fulfilled on your system:

- Homebrew package manager
- gfortran (build tested with version 9.2.0)
- netCDF (from homebrew)
- HDF5
- CRTM REL-2.3.0 or higher
- lblrtmio v1.0.0

Preliminaries:
==============
The root folder contains a make.macros file 
which contains all necessary environment 
variables for building CRTM_coef in a macOS
environment.
For macOS, the file is called:

	make.macros.macOS_brew

You will find other, similar make.macro 
files for other system configurations.
Before attempting to build an executable in
the CRTM_coef repository, please ensure that
all necessary paths in make.macros.macOS_brew
are set correctly.
These include:

- CRTM_PATH: The location of your CRTM folder
- NC4_DIR_BREW: The path of your homebrew 
  netCDF installation
- HDF_DIR_BREW: The path of your homebrew
  HDF installation
- LIBLBLRTMIO: The path of the lblrtmio
  library (included in the CRTM_dev repo)

Build instructions:
===================
In order to build a specific executable of
CRTM_coef, you need to enter the corresponding
folder in CRTM_coef/src and compile it from
scratch with the following command:

make -f Makefile.brew

This invokes 'make' with the specific makefile
for homebrew. Makefile.brew relies on the 
path variables set in make.macros.macOS_brew,
so please ensure that all paths are set 
correctly.