Attribute data are additional data that are collected at the same time as GPS data. For example, if you collected the location of a plant, you may also collect the species name, plant height, and number of flowers. This additional data is called attribute data.
Each type of GPS unit has a different way to collect attribute data. The GeoXT unit uses a data dictionary created beforehand to gather attribute data. The Hiper Pro and Total Station use what are called "codes" to collect attribute data.