The article “Sensing the ocean” by Tom Sanford, Kathie Kelly, and David Farmer (PHYSICS TODAY, February 2011, page 24) was particularly interesting to me, since I have been working in that field for years. Because of the invention, development, and use of new platforms such as floats, gliders, and AUVs (autonomous underwater vehicles), ocean sensor systems are now delivering the parameter values of interest with adequate temporal and spatial coverage. But since the platform has a strong influence on the performance of the sensor and on the spatial and temporal characteristics of the collected data, I am sure that one should not separate the two. For instance, a multibeam sonar system is very susceptible to platform motions, so the spatial resolution will be limited by that particular platform characteristic. And for a temperature sensor with a finite time response, different platform travel speeds will result in different spatial resolutions. It would be sensible, then, to think about a sensor and its platform as a single entity. In space science, that idea is already established; the feature article covers it in describing satellite-mounted sensors.
Ocean science has undergone a remarkable transition from purely point sampling in space and time to well-thought-out ocean observation strategy. Sanford, Kelly, and Farmer have significantly contributed to the remarkable development in the field.
