add usage readme

README.org

@@ -16,3 +16,64 @@ main use cases.
   properties as a fast alternative to [[https://biosnicar.vercel.app/][biosnicar]].
 - *inverse mode*: infer surface properties from snow spectral albedo
   observations.
+
+* Installation
+
+=snowlaps= can be installed via the command line with [[https://docs.conda.io/en/latest/][conda]] and [[https://pip.pypa.io/en/stable/][pip]]:
+
+#+begin_src shell :results verbatim
+
+# clone repository in the folder of your choice
+git clone [email protected]:openosmia/snowlaps.git
+
+# move into snowlaps directory
+cd snowlaps
+
+# create conda environment
+conda env create -f environment.yml
+
+# activate conda environment
+conda activate snowlaps
+
+# install snowlaps
+pip install -e .
+
+#+end_src
+
+Installation can be sped up using the fast cross-platform package
+manager [[https://mamba.readthedocs.io/en/latest/][mamba]] (reimplementation of the conda package manager in C++),
+simply use =mamba= instead of =conda= in the instructions above.
+
+* Usage
+
+=snowlaps= can be used directly as a Python package or interactively
+via a Streamlit app.
+
+** Running the code
+
+Example scripts are provided in [[https://github.com/openosmia/snowlaps/tree/main/examples][snowlaps/examples]].
+
+- *example 1*: forward run of the snowlaps emulator
+- *example 2*: inversion of hyperspectral albedo measurements
+- *example 3*: comparison of snowlaps and biosnicar predictions
+
+** Using the app
+
+The Streamlit app can be run locally via the terminal:
+
+#+begin_src shell :results verbatim
+
+# move into snowlaps directory
+cd snowlaps
+
+# start Streamlit app on http://localhost:8501
+./start_app.sh
+
+#+end_src
+
+
+[[./data/assets/app_forward.png]]
+
+
+
+