Fill DL3 overview page
-.. _DL3_general:
+.. _overview_DL3:
The Data Level 3 (DL3) format
=============================
+The data level 3 FITS files consisting of event lists,
+instrument response information (effective area, point spread function, energy
+dispersion, background) and extra information concerning the observation
+(pointing direction, time), as well as two index tables that list the
+observations and declare which response should be used with which event data
+
Data levels in CTA
------------------
@@ -29,17 +35,22 @@ Application in gammapy
The main classes in Gammapy to access the DL3 data library are the
`~gammapy.data.DataStore` and `~gammapy.data.DataStoreObservation`.
They are used to store and retrieve dynamically the datasets
-relevant to any observation (event list, IRFs and other relevant informations).
-
+relevant to any observation (event list in the form of an `~gammapy.data.EventList`,
+IRFs see :ref:`irf` and other relevant informations).
-`~gammapy.data.Observations`, `~gammapy.data.EventList` and various other
-classes. To learn how to work with this data, and how to reduce it to the
-datasets level, see :ref:`gammapy.analysis <analysis>`, :ref:`gammapy.data
-<data>`, :ref:`gammapy.irf <irf>`, :ref:`gammapy.cube <cube>`,
-:ref:`gammapy.spectrum <spectrum>`.
+Once some observation selection has been selected, the user can build a list of observations:
+a `~gammapy.data.Observations` object, which will be used for the data reduction process.
+A convenient way to do this is to use the high level interface, see :ref:`gammapy.analysis <analysis>`.
Example notebooks
^^^^^^^^^^^^^^^^^
+* CTA DL3 handling <notebooks/cta.html>`__
+* HESS Data Release 1 handling <notebooks/hess.html>`__
+
Relevant API
^^^^^^^^^^^^
+
+* :ref:`gammapy.data<data API documentation>`
+* :ref:`gammapy.irf <irf API documentation>`
+
