All NIC regional sea ice, Great Lakes, and Chesapeake Bay analyses are derived from near real-time integration of remotely sensed and in-situ oceanographic/meteorological observations. These analyses are produced following standard analysis procedures, which optimize the use of data that vary widely in availability, scale, and resolution. These operational data sources can be grouped into the following categories: satellite-derived data, aerial ice reconnaissance, ship/shore stations observations, drifting buoy reports, meteorological guidance products, ice prediction model output, climatology and sea ice information obtained from international partners such as foreign ice services. Documentation recording the percentages of each data types used in each analysis can be found in a weekly metadata narrative.