ProcessingChains/diapOTB_S1IW_Chain.md

@@ -2,10 +2,10 @@
 
 # diapOTB_S1IW.py
 
-This workflow works on S1 IW data.
-
 ## Description
 
+This workflow works on S1 IW data. It represents the main processing for this data and needs as inputs  : two SLC images and an only DEM file. The inputs should be filled into the configuration file descripted in the next chapter.
+
 This chain is divided into four parts descrided below :
 
 
@@ -110,5 +110,5 @@ Five sections compose the configuration file :
 	* **Filtered_parameter_alpha :** alpha parameter for Goldstein filtering	
 
 
-The processing chain needs metadata to launch the applications. Thus the path to the input images must be into the native directory for each kind of products (i.e SAFE directory for Sentinel-1 products).
+The processing chain needs metadata to launch the applications. Thus the path to the input images must be into the native directory for each kind of products (i.e SAFE directory for Sentinel-1 products). The DEM has to be a unique file but can be built with several tiles by using some gdal commands, for example.
 For that moment the ground geometry for interferogram does not provide satisfactory results.