I would be most be grateful if you could let me know what baseline type should be selected or created in ArcGIS to be used by DSAS add-in when we want to assess temporal changes of a shoreline?
DSAS provide support for multiple shorelines against a reference. In the absence of a baseline data, you may add any fictitious shoreline for the first reference simu, this is supported by the DSAS. Hope that helps. :-)