What is NOSE and how does it work with AMSR-E data?

AMSR-E Level-2A data files use a Nominal Orbital Spatial Extent (NOSE) to specify spatial coverage. These are predefined polygons based on the AMSR-E's viewing geometry and Aqua's orbital characteristics. The metadata shows the spatial coverage of a data file by the Product Specific Attributes (PSAs) StartingPolygonNumber, EndingPolygonNumber, and NominalPassIndex. These values are not meaningful for data users, but rather they are used by the system in spatial queries. So if you want to know which granules cover your area of interest, you must include this as a criterion in your search. Note that the Gringpointlatitude and Gringpointlongitude metadata attributes do not provide correct spatial coverage information. Also note that each data granule contains complete geolocation information in the form of pixel location arrays, which conform to HDF-EOS swath standards.