ASTER User's Guide - NASA

ASTER Users HandbookWhat is User-Friendly Metadata (UFM) and how can I use it to make my metadata filefriendlier to use?Since there is a large volume of metadata that is produced along with ASTER Level-1 datasets, itis not always practical to print the entire metadata file which can run into many pages. UserFriendly Metadata (UFM) is a utility that helps condense and reformat your metadata file into amore usable size. It outputs the metadata to a hypertext markup language (html) file that can beviewed using any web browser. It is available for all flavors of UNIX and NT platforms. It isavailable free of charge and can be downloaded from:http://hdfeos.gsfc.nasa.gov/hdfeos/SoftwareDist.html.On average, it condenses an ASTER L1 metadata file from 84,000 bytes to 25,000 bytes. UFMpresently works only with the ECS-produced .met file.What are G-Rings and G-Polygons?A G-Ring (or Geometry Ring) is a closed sequence of ordered pairs of coordinates of latitudeand longitude in floating point that define the boundary of the area. Latitude and longitude arespecified in decimal degrees with north latitudes positive and south negative, east longitudepositive and west negative. The first and last points in the set of coordinates must be the same(Figure 31).The outer G-Ring describes the outside edge of the G-Polygon (the full coverage extent). InnerG-Rings describe any holes that may occur in the G-Polygon (areas of missing coverage withinthe outer ring). The GPolygon class contains the G-Ring attribute for the exclusion ring flag,which is added to each polygon definition to describe whether the polygon is an inner or outerring of coverage.77