The National Oceanic and Atmospheric Administration (NOAA) Operational Significant Event Imagery (OSEI) World Wide Web site (http://www.osei.noaa.gov) was established in January 1997 in response to requests from NOAA management, scientific researchers, crisis managers and the general public for an online source for near-real-time satellite imagery of environmentally significant events. The site is operated and maintained by personnel in the Satellite Services Division (SSD) of the Office of Satellite Data Processing and Distribution (OSDPD), National Environmental Satellite, Data, and Information Service (NESDIS), NOAA. It features high-resolution, detailed imagery of worldwide events such as dust storms, fires, floods, icebergs, oceanographic features, severe weather, snow cover, severe storms, tropical cyclones and volcanic activity visible in remotely sensed data available at the NOAA Science Center in Camp Springs, Md.

The site provides Daily Operational Significant Event Imagery Reports (DOSEIRs), available via e-mail subscriptions or on the web site, which outline the most recently posted imagery and provide direct links to each image. Images are described with short narratives. Site users are private citizens worldwide; local, state, federal and foreign government agencies; print, broadcast and Internet-based media sources; educational institutions; and the scientific community. In addition, the site offers a media e-mail alert service that informs media subscribers of particularly newsworthy current imagery.

Recent developments include the integration of Geospatial Information System technology, the addition of image metadata, and the availability of a metadata search engine for locating archived images. Imagery on the site demonstrates the potential uses of environmental satellite data in worldwide natural hazards risk management, and serves as a gateway to other NESDIS satellite derived products.