A VMP, which stands for Vertical Microstructure Profiler, is an untethered microstructure profiling system that, after being released, sinks to a pre-defined ocean depth. It collects data on the way down, through various sensors, meters, and probes, both in the nose cone of the instrument and in the main body.
After the VMP reaches the pre-defined depth, the instrument releases ballast weights so that it becomes positively buoyant and rises to the ocean surface.
Once on the surface, the VMP has several methods of alerting its location. This includes a strobe light, a radio beacon, and an ARGO positioning transmitter. After the VMP is safely recovered, data is downloaded via USB.
The MMM group has two deep ocean microstructure profilers in it’s pool of resources: A VMP-5500 named “Vito”, and one named “Vader”.