The VENUS Zooplankton Acoustic Profiler (ZAP) instrumentation records an echo-profile every 2 seconds. The resulting series of profiles can be sorted by each day into a data cube (left), with hour of the day along the x-axis (centered at mid-night), day of the year in the y-axis (into the page), and vertical range above the bottom in the z-axis. This data cube can then be sliced in various planes to reveal daily and seasonal patterns. On the right is a one hour section of the data expanded to full resolution.
Reference: Borstad, G., L. Brown, M. Sato, D. Lemon, R. Kerr, and P. Willis. 2010. Long zooplankton time series with high temporal and spatial resolution. OCEANS 2010, pp.9. DOI:10.1109/OCEANS.2010.5664585.
http://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=5664585
