DOC: clarify S1 Safe product

Documentation/SoftwareGuide/Latex/OrthoRectification.tex

@@ -173,8 +173,8 @@ Spot5, Landsat and Quickbird sensor models.
   \item If no model was found, search any RPC tags in the input image. When the
 tags are present, an \code{ossimRpcModel} is created.
   \item If still no model was found, search for a valid sensor model in other
-files attached to the current dataset. For instance, with a Sentinel 1 SAFE
-dataset, it will inspect underlying \code{.tiff} files. With a VRT dataset, it
+files attached to the current dataset. For instance, with a Sentinel-1 SAFE XML
+product, it will inspect underlying \code{.tiff} files. With a VRT dataset, it
 will inspect the files referenced by the VRT.
 \end{enumerate}