About: http://webisa.webdatacommons.org/155641411

Property	Value
http://www.w3.org/1999/02/22-rdf-syntax-ns#type	http://www.w3.org/ns/prov#Entity
http://www.w3.org/ns/prov#value	Thus ground speed is a measurement that is taken in the air, what does this account for, well how about wind direction, speed, your course, and your true airspeed.
http://www.w3.org/ns/prov#wasQuotedFrom	airliners.net