IMS Daily Northern Hemisphere Snow and Ice Analysis at 4 km and 24 km ResolutionThe National Environmental Satellite, Data, and Information Service (NESDIS), part of the National Oceanic and Atmospheric Administration (NOAA), has an extensive history of monitoring snow and ice coverage. Accurate monitoring of global snow and ice cover is a key component in the study of climate and global change as well as daily weather forecasting. By inspecting environmental satellite imagery, analysts from the Satellite Analysis Branch (SAB) at the Office of Satellite Data Processing and Distribution (OSDPD), Satellite Services Division (SSD), created a Northern Hemisphere snow and ice map from November 1966 until the National Ice Center (NIC) took over production in 2008. Initially, the product was produced with a nominal spatial resolution of 190 km and a temporal resolution of seven days. In 1997, the Interactive Multisensor Snow and Ice Mapping System (IMS) became operational, giving the satellite analysts improved access to imagery and drawing tools. Since the inception of IMS, the charts have been produced daily at a nominal resolution of 24 km (1024 x 1024 grid). Beginning in February 2004, further improvements in computer speed and imagery resolution allowed for the production of a higher resolution daily product with a nominal resolution of 4 km (6144 x 6144 grid). NSIDC archives and distributes the 24-km and the 4-km IMS product in ASCII text format from February 1997 to present and February 2004 to present, respectively. NSIDC also distributes browse images in GIF format and latitude and longitude grids for these products. In June 2006, NSIDC started distributing 4-km GeoTIFF files for use with GIS applications. Note: The IMS product is considered operational, but NIC does not guarantee availability or timely delivery of data via the NIC Web server, and NSIDC does not guarantee availability of this product via the NSIDC Web server. These servers should not be used to support operational observation, forecasting, emergency, or disaster mitigation operations, either public or private. Users with real-time operational needs should visit the NIC Web site and contact the National Ice Center Liaison to request access to the operational server.
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