Merge pull request #45 from lmichel/update_introduction

Update introduction in MANGO.tex

Author: loumir

doc/MANGO.tex

@@ -119,47 +119,45 @@ \section{Introduction}
 \citep{note:stcvot} \citep{note:seb}.
 In this case the goal was no longer to design a source model but to provide a complete description of
 individual quantities (positions, velocity, fluxes, magnitudes…).
-None of these proposals have come to completion due to the complexity of the task.
+None of these proposals has come to completion due to the complexity of the task.
 
 The source DM issue resurfaced at the spring 2018 Interop in Victoria during an hands-on session
 focusing on the tools available to work with VO data models and especially with VO-DML.
-The goal of this session was to annotate data from different origins in order to make them
-interoperable with each other.
-The main concern expressed during this session was not much related to the tools themselves
-but indeed to the lack of models for sources.
+The goal of this session was to annotate astronomical data from different origins in order to make them
+interoperable with each other. The main concern expressed during this session was not much related to the tools themselves but indeed to the lack of models representing sources.
 This is a paradox in the VO world: source data which represent the basic building
 blocks of astronomers' work, is not modelled.
 This paradox can be explained by the fact that the observation of source objects is multi-faceted.
-In a general way, the way features for source data are described and organised depends on
+In a general way, the way features for source data are described and organized depends on
 the targeted science case.
 Principal investigators and archive designers set up the data profile and structure it according
 to this goal which varies from one project to another.
 Therefore this diversity cannot be served by a single static data model describing a source
 item for all possible cases.
-Having a global source model would lead to a very complex solution not usable in practice.
+Having a global all-purpose source model would lead to a very complex solution not usable in practice.
 
-This standard proposes to overcome this paradox and presents a template model gathering independent
+In contrast this specification proposes to overcome this paradox and presents a template model gathering independent
 components from VO existing models embedded on demand in a container.
 
 MANGO is not designed to describe what a source is but to help clients to discover and to understand
-the quantities available for a particular source instance.
-VOtable data mapped on MANGO with Mivot (2023ivoa.spec.0620M) annotations can be consumed quantity 
-par quantity instead of column per column.
-The way complex quantities are built is  described by MANGO but no longer by the clients.
+the features (i.e quantities) available for a particular source instance.
+VOTable data mapped on MANGO with MIVOT (2023ivoa.spec.0620M) annotations can be consumed on a feature basis 
+instead of column per column.
+The way complex quantities are built is described by MANGO but no longer by the client applications.
 
 \subsection{Role within the VO Architecture}
 
 \begin{figure}
 \centering
 
 \includegraphics[width=0.9\textwidth]{role_diagram.pdf}
-\caption{Architecture diagram for this document}
+\caption{Architecture diagram showing the MANGO DM and its relations to other IVOA specifications}
 \label{fig:archdiag}
 \end{figure}
 
 Fig.~\ref{fig:archdiag} shows the role this document plays within the
-IVOA architecture \citep{2010ivoa.rept.1123A}.
-
+IVOA architecture \citep{2010ivoa.rept.1123A}. This model reuses existing data models like Measure and Coords, and PhotDM. Implementations can use the TAP protocol and distribute data model instances in VOTable. 
+UCD, VOUnits and Vocabularies are also re-used.  
 
 \section{Representing observed astronomical objects : Use Cases and  Requirements}