The Alternative Editor Observed Data tab is where you can associate DSS files and timeseries with any location and datatype for which you have selected observed data. 

Defining Observed Data

While defining your reservoir network, if you have specified (by checking the appropriate box or boxes in the Observed tab within each element's editor in the Network module) that observed data is available for individual reservoirs, junctions, reaches, diversions, and diverted outlets, then the Observed Data tab of the Alternative Editor will list these locations in a table along with the DSS path information associated with them, as shown in "Figure: Alternative Editor - Observed Data Tab".

Figure: Alternative Editor - Observed Data Tab