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