@prefix cpm: . @prefix dc: . @prefix dcat: . @prefix dce: . @prefix dct: . @prefix dcterms: . @prefix grg: . @prefix iop: . @prefix ns0: . @prefix ns1: . @prefix owl: . @prefix pav: . @prefix prov: . @prefix puv: . @prefix qudt: . @prefix rdf: . @prefix rdfs: . @prefix reg: . @prefix sdo: . @prefix semapv: . @prefix skos: . @prefix sssom: . @prefix void: . @prefix xsd: . rdf:type sdo:DefinedTerm ; sdo:description "An instrument placed on the seabed that transmits pulses of sound upwards into the water column and times how long echoes from features in the water column such as steep density gradients take to return."@en ; sdo:inDefinedTermSet ; sdo:name "inverted echo sounder"@en ; sdo:termCode "SDN:S04::S04239" .