Disdrometer is an instrument that is typically used for measurement of precipitation microphysical characteristics such as raindrop/snow size distributions, shapes, and fall velocities as well as identification of precipitation type (e.g. snow, hail, rain). Disdrometers are used in various applications related to geophysical sciences (e.g. meteorology, atmospheric sciences, hydrology) and engineering (e.g. civil engineering, environmental engineering). Potential user segments for disdrometers include federal agencies and similar international agencies, research institutes, universities, airports, and weather stations. Majority of the disdrometer systems are either optical or impact type disdrometers, which are associated with various instrumental measurement artifacts. Although optical disdrometers have a much greater potential for commercial success over other disdrometer types, this potential has been mainly hampered due to measurement accuracy issues related to the optical depth of field.
This team has developed the Advanced Optical Disdrometer (AOD) with high-speed image recording capability. The high-speed imaging capability of the AOD provides an ability to monitor the actual shapes and motions of the hydrometeors. Using image processing, the AOD provides information on the shapes (e.g. diameter, vertical to horizontal axis ratio, canting angles) and motions (e.g. fall velocity, acceleration) of hydrometeors with high accuracy. There are two critical innovative components of the proposed system: volume confinement principle and the high-speed (up to 1000 frames per second) image recording capability. Volume confinement principle overcomes the measurement accuracy issues that are pertinent to optical disdrometers and the high-speed image recording provides an ability to monitor the actual shapes and motions of the particles.
