@prefix dct: . @prefix ns1: . @prefix ns2: . @prefix rdfs: . @prefix skos: . a skos:Concept ; ns1:creator "European Space Agency", "Spot Image S.A.", "Spot Image S.A. " ; ns1:date "2010-03-23" ; ns1:source ; dct:created "2010-03-23" ; dct:modified "2012-02-14" ; ns2:hasProfile ; rdfs:seeAlso , , ; skos:altLabel "GPS" ; skos:definition "Global Positioning System time, is the atomic time scale implemented by the atomic clocks in the GPS ground control stations and the GPS satellites themselves. GPS time was zero at 0h 6-Jan-1980 and it is not adjusted for leap seconds. It is maintained with a constant 19 seconds lag on TAI."@en ; skos:exactMatch , , "urn:ogc:def:trs:USNO::GPS" ; skos:prefLabel "GPS Time"@en .