diff --git a/docs/source/index.rst b/docs/source/index.rst
index 455c600..dad3296 100644
--- a/docs/source/index.rst
+++ b/docs/source/index.rst
@@ -113,7 +113,7 @@ Download the astap_amd64.deb and:
 
 	sudo apt-get install ./astap_amd64.deb
 
-To use Ima.calibwcs you have to install `Astrometry.net and its quad files <https://astrometry.net/use.html>`_:
+To use Ima.calibwcs() you have to install `Astrometry.net and its quad index files <https://astrometry.net/use.html>`_:
 
 .. code-block:: bash
 
@@ -121,6 +121,44 @@ To use Ima.calibwcs you have to install `Astrometry.net and its quad files <http
 	sudo apt install astrometry-data-tycho2 
 	sudo apt install astrometry-data-2mass
 
+The executable is /usr/bin/solve-field. The default directory where you have to place the index files
+is /usr/share/astrometry. However, if you prefer to install the index folders (4100, 4200, 5200) in
+another directory, you must change the following line in the configuration
+file /etc/astrometry.cfg (sudo):
+
+.. code-block:: bash
+
+    add_path /usr/share/astrometry
+
+For example:
+
+.. code-block:: bash
+
+    add_path /home/myself/astrometry.net
+
+Check solve-field is working before using Ima.calibwcs():
+
+WCS calibration in total blind:
+
+.. code-block:: bash
+
+	cd ~/Documents
+	solve-field --crpix-center --overwrite guitastro/tests/data/m57.fits
+
+WCS calibration in case you know approximate coordinates:
+
+.. code-block:: bash
+
+	cd ~/Documents
+	solve-field --ra 180 --dec 0 --radius 3 --crpix-center --overwrite guitastro/tests/data/m57.fits
+
+WCS calibration if you know approximate spatial sampling:
+
+.. code-block:: bash
+
+	cd ~/Documents
+    solve-field --scale-units arcsecperpix --scale-low 3.5 --scale-high 3.7 --crpix-center --overwrite guitastro/tests/data/m57.fits
+
 5.2. Resources for Windows
 ==========================
 
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