Executive Summary
Sparv Embedded is contributing advanced sensor technology to ICECHIP (In-situ Collaborative Experiment for the Collection of Hail in the Plains), the most extensive hailstorm research initiative in over four decades. Funded by the US National Science Foundation and conducted across the central United States in May and June 2025, ICECHIP brings together researchers from 15 institutions to improve hailstorm forecasting, modeling, and real-time situational awareness.
Sparv’s Windsond S1 balloon-borne sensor is used to measure atmospheric conditions—such as wind, temperature, pressure, and humidity—near active hailstorms. Complementing this, Sparv’s custom-designed Hailsonde probes simulate real hailstones and collect in-situ data on hailstone growth, movement, and storm microphysics. These probes also record acceleration and collision data, offering unprecedented insight into hail formation and behavior.
Together, these technologies help fill critical gaps in hail research and support the development of more accurate radar-based detection and forecasting models. Sparv Embedded is proud to support this landmark study in severe weather science.
Why is the Study Important?
Hailstorms pose a growing safety threat to the public and they impact many economic sectors, such as agriculture, aviation, renewable energy, and housing. There exists a pressing need to improve i) our understanding of hailstorm dynamics, ii) hail forecasting models, and iii) our overall situational awareness of hailstorms as they develop and evolve. Recognizing this, the US National Science Foundation has funded the ICECHIP (In-situ Collaborative Experiment for the Collection of Hail in the Plains) project. The experimental phase of the study is being conducted in the US during May and June of 2025. ICECHIP represents the largest and most comprehensive hail study in over 40 years. Researchers from 15 institutions are coming together to participate in this much needed study. For additional information see ICECHIP | Earth Observing Laboratory and More damaging than tornadoes, hail may finally get the scientific attention it deserves | Science.
The Role of Sparv Embedded Sensors in ICECHIP
Windsond S1
Data obtained from the Sparv Embedded Windsond S1 will play a central role in capturing the environmental conditions near hailstorms. The Windsond is one of Sparv’s flagship sensors and is used to provide measurements of atmospheric wind, pressure, temperature, and humidity as a function of height as the instrument package is carried aloft using a helium-filled balloon. Note: a newer version of the S1 is now available (Windsond S2).
Image from UCAR (credit Victor Gensini)
Hailsonde / Coinsonde
Hailsonde is a novel component of ICECHIP. The primary objective of deploying hailsondes in ICECHIP is to collect in-situ data on hailstone growth, movement, and the microphysical processes occurring within severe thunderstorms. Hailsondes are innovative spherical probes meant to simulate the size (6.5 cm in diameter) and weight (24 grams) of a “typical” hailstone (IEEE Spectrum). See the images below. The Hailsonde consists of a miniature sensor board custom made by Sparv, which is encased in a 3D-printed shell. The sensor board is based on Sparv’s Coinsonde. As a result, the hailsonde can measure temperature, humidity, GPS location, and wind conditions. By analyzing the trajectories and environmental conditions experienced by these probes, researchers aim to enhance understanding of hail formation and improve the accuracy of radar-based hail detection and forecasting models (NSF). As a special adaptation, the hailsondes also record high-resolution acceleration and count the number of collisions with rain and other hail separately. The dense acceleration data is logged to onboard storage and the collision counts are transmitted in real-time to the ground station.
Components of the Hailsondes ready to be assembled. Image from NSF. (Credit Australian Bureau of Meteorology)
Rendering of the Hailsonde design. Image from NSF. (Credit Australian Bureau of Meteorology)
A collection of Hailsondes being charged and calibrated. Image from NSF. (Credit Australian Bureau of Meteorology)
The Hailsonde offers a novel approach that addresses longstanding gaps in hail research by providing detailed observations of hailstone behavior within storms, thereby contributing to more effective prediction and mitigation strategies for hail-related hazards.
Sparv Embedded is proud to be able to contribute to this important research study.
About the author
Phil Chilson
Atmospheric Physicist & Customer Service
Phillip applies meteorological expertise to support instrument development, deployment, and data collection. Ensures high-quality data from the Sparv instrumentation suite. Partners with clients to design customized sampling strategies.