Balloon borne HYVIS is in-situ measuring instrument to capture Upper-air cloud and/or ice crystal particles. HIVIS, connected with a GPS radiosonde, takes in ambient particles with sizes ranging from a few dozen μm to hundreds μm during ascension. Collected particles are attached to transparent film and then particle images are captured using two different cameras (microscope and close-up) alternately.
The captured video signals (images) are transmitted to ground HYVIS receiver system using 1680 MHz*1 radio telemetry. Antennas of the receiver system are controlled by GPS positioning information obtained from GPS radiosonde and hence automatically chase the flying HYVIS, which facilitates easy flight operation and minimizes tracking failure. The video images captured provide cloud property (shape, size, and number concentration) of sampling particles with vertical profile.
HYVIS has been using for in-situ cloud observations (microphysical properties in cloud), validation for classification of cloud particles by polarimetric radar, and numerical model simulation.
*1) Applicable Radio Laws/Regulations should be complied with.