poly_mask = water1 is water areas (either within the bay or ponds) which should be removed from any elevation models.
poly_mask = lidar are areas of valid lidar data surrounded by areas of water (data islands). Such areas include marsh, tidal flats, and features within salt ponds. This data should be retained in elevation models.
poly_mask = water2 are areas of water that fall within the above describe 'data islands' of valid lidar data surrounded by water. This consists of channels within marsh islands. These areas should be removed from elevation models.
For additional information of how these polygons were created see Foxgrover, A.C. and Jaffe, B.E., 2005, South San Francisco Bay 2004 Topographic Lidar Survey: Data Overview and preliminary Quality Assessment: U.S. Geological Survey Open-File report 2005-1284, 57 p. [URL: <http://pubs.usgs.gov/of/2005/1284/>]
poly_mask = water1 is water areas (either within the bay or ponds) which should be removed from any elevation models.
poly_mask = lidar are areas of valid lidar data surrounded by areas of water (data islands). Such areas include marsh, tidal flats, and features within salt ponds. This data should be retained in elevation models.
poly_mask = water2 are areas of water that fall within the above describe 'data islands' of valid lidar data surrounded by water. This consists of channels within marsh islands. These areas should be removed from elevation models.