GGRC30H3 Chapter Notes - Chapter week 3: Extended Ascii, Binary Number, Gif
Document Summary
Spatial model must be translated into a set of numbers stored on a computer: binary format: may be represented as a series of 0s and 1s. Several bytes are required when representing large numbers: two bytes will store up to 65536 different numbers (integer) used to store terrestrial elevation, real numbers (decimal) require more bytes (4 bytes) Binary numbers are used to represent codes: spatial and attribute data may be represented as text or as standard codes common when raster or vector data are concerted for export or import among different gis systems. Comparing: ascii data sets are much large than binary data, geographic data use combination of binary and ascii data stored in files, binary data are used for coordinate information; ascii or other codes used for attribute data. Data files are linked by file pointers, indexes, or other structure: a pointer is an address or index that connect one file location to another.
