upsweep upsweepa signal that increases in frequency over time. Related Articles: Pygmy Blue WhaleMid-frequency Active SonarTutorial: Seismic AirgunSeismic AirgunsTutorial: Sonar SourceSonarFalse Killer WhaleRoss SealSei WhalePantropical Spotted Dolphin Chris Knowlton2019-01-31T14:46:01-05:00