I have derived Topographic Wetness Index (TWI)/CTI with ArcGIS 10.3 using 30m DEM resolution. Earlier, it was propagating negative values which were mainly confined to ridges. I have restructured the 'Raster Calculator' expression as below and got rid of negative values.
Ln(("Flow_acc"+ 1 ) * 900/"Tan_SlopeRad")
Now, How would I deal with values having ''No Data'???