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CBDR is an acronym for Constant Bearing, Decreasing Range, and refers to an object on an intercept (or collision) course with a ship.

Raiders on attack approach to Galactica can be CBDR (TRS: "Final Cut").

When Pegasus first appears on DRADIS, Lieutenant Gaeta indicates the DRADIS target as CBDR to Galactica (TRS: "Pegasus").