Real-time Non-contact Millimeter Wave Characterization of Water-Freezing and Ice-Melting Dynamics

Abstract

We applied millimeter wave radiometry for the first time to monitor waterfreezing and ice-melting dynamics in real-time non-contact. The measurements were completed at a frequency of 137 GHz. Small amounts (about 2 mL) of freshwater or saltwater were frozen over a Peltier cooler and the freezing and melting sequence was recorded. Saltwater was prepared in the laboratory that contained 3.5% of table salt to simulate the ocean water. The dynamics of freezing-melting was observed by measuring the millimeter wave temperature as well as the changes in the ice or water surface reflectivity and position. This was repeated using large amounts of freshwater and saltwater (800 mL) mimicking glaciers. Millimeter wave surface level fluctuations indicated as the top surface melted, the light ice below floated up indicating lower surface temperature until the ice completely melted. Our results are useful for remote sensing and tracking temperature for potentially large-scale environmental applications, e.g., global warming.

Millimeter-Wave Thermal Analysis Development and Application to GEN IV Reactor Materials

“…Polarization sensitive measurements could unambiguously track anisotropic material characteristics. Past work has applied MMW techniques to nuclear waste glass melter measurements [10], water-ice freezing dynamics [11], and precision high-temperature superconductor resistivity measurements [12].…”