Project Methods
On-Screen Mapping with ArcView's Habitat Digitizer
Introduction
The Habitat Digitizer Extension to ArcView 3.1® was developed to facilitate mapping benthic habitats of Puerto Rico and the U.S. Virgin Islands using the classification scheme described in Classification Methods. The extension was originally created to map habitats using this scheme by visually interpreting orthorectified aerial photos.
- The extension’s capabilities have been expanded to allow users to map from other georeferenced image data such as satellite images and side scan sonar.
- The extension allows users to rapidly delineate and attribute polygons using simple menus.
- It also allows new hierarchical classification schemes to be easily created, modified, and saved for use on future mapping projects.
Accessing the Extension
The extension is available on the Benthic Habitats of Puerto Rico and the U.S. Virgin Islands CD-ROM or over the Internet at http://ccma.nos.noaa.gov/products/biogeography/. The extension and accessory files are found in "data/ext/hab_dig.zip". This folder contains three files including:
- habitat.avx-the extension
- coral.hcs-a classification scheme for tropical marine habitats
- coral.avl-an example legend for the coral.hcs classification scheme
Hardware and Software Requirements
The habitat digitizer extension is compatible with ArcView 3.1® and requires hardware similar to that recommended for proper operation of ArcView. Additional memory may enhance performance for handling large image files. The appropriate Image Support extension (TIFF, MrSID®, etc.) is required depending on the format of the image files used. The Image Analyst extension is not necessary, but is recommended to facilitate manipulation of image brightness, contrast, and color balance.