GIS topologic quality was established by executing ArcView extension routines that check for: overlapping polygons, multipart polygons, sliver polygons, void polygons and zone attribute check. Additionally checks for adjacent polygons with the same habitat attributes were completed. All errors were identified and corrected. This file is believed to be logically consistent.
All IKONOS imagery was processed by NOAA prior to map production. The imagery was corrected for atmospheric and water column effects, pan sharpened and deglinted. During the digitizing process, images were stretched and contrast, brightness and color balance were modified using the Arc View Image Analysis Extension to enhance features in the processed imagery. The overall map production plan includes a first draft map completed with features in the imagery where uncertainties existed, due to confusing or difficult to interpret signatures, identified for future ground validation effort. An ArcView GIS point theme was generated with points positioned on the features of uncertain habitat type or along transects though gradients between habitat types. The GIS points are converted to GPS waypoints using Trimble Pathfinder Software and are navigated to in the field using a Trimble GeoExplorer 3 GPS data logger. A benthic habitat characterization is conducted at each site by use of a tethered video camera snorkeling, free diving, or where water depth and clarity permitted, by observation from the surface. GPS data were collected at each location and site ID, depth, habitat type, zone and the method used to make the assessment are recorded. A second draft of the map is generated incorporating these ground validation data. This is a draft 1 map product. Though the product is topologically clean and meets NOAA GIS standards, attribute accuracy is at an interim level of production and will be considerably modified prior to draft 2 and final publication.