1. General. A process of linking together radar target reports (plots and tracks) and other information relating to one particular object.
2. SASS-C. All plots relating to the same target object are associated (chained) using the Object Correlator (OC). The chaining process allocates the same aircraft identity number to each plot which relates to one target object. Any plots which cannot be correlated to a target object are classified as unchained and are allocated a negative aircraft identification.
EUROCONTROL, Surveillance Analysis Support System for ATC-Centre: SASS-C Glossary