About: http://webisa.webdatacommons.org/235321876

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	A magnetic compass requires a careful calibration procedure and complicated compensation algorithms before obtaining precise heading because of its vulnerability to several types of errors.
http://www.w3.org/ns/prov#wasQuotedFrom	ieee.org