Hi, i'm getting an error message when I do the Viewshed analysis.
I did the Hillshade, marked the tower locations using points shp file, and entered data in the towers attribute table by adding fields OFFSETA, OFFSETB.
Then, when I did the Spatial Analyst > Viewshed, the error message appears, saying "Error in executing grid expression. No valid Obeservation points present. Point 5 with coordinates 0.000, -0.115901954612E+25 is NODATA.".
Please held me in correcting the error.
Thanks
