Cloud Sensor Resources

The supercooled liquid water content (SLWC) sensor and the similar liquid water content (LWC) sensor operate by measuring the buildup of water on a vibrating wire. The following documents provide the mathematical derivations of the equations and also provide guidance for processing the data.

Basic Derivation

This paper covers the detailed derivation of the SLWC equations as used with Anasphere's SLWC sensor.
SLWC Detailed Derivation (pdf)

Detailed Application Equations

The following paper covers the processing of SLWC sonde data.
SLWC Equation Implementation (pdf)

The following paper covers the processing of LWC sonde data. It is recommended that users review the SLWC processing paper first, as it is a slightly simpler and easier to understand case.
LWC Equation Implementation (pdf)

Sensor Instructions

The following instructions address the basic use of the SLWC and LWC sondes, including how to replace the wires. In the case of LWC sondes, wires should be replaced after each flight.
LWC and SLWC Sonde Instructions (pdf)


XDATA is an open data format developed by NOAA which is used to exchange digital data with radiosondes. This format is implemented with our SLWC and LWC sondes, and our SmartTether systems are also able to accept XDATA. Details of the XDATA format can be found here.


An example of complete data reduction is given by Serke et al.1
The SLWC sensor was featured in NASA's Spinoff magazine.2

1Serke, D. et al. "Supercooled Liquid Water Content Profiling Case Studies with a New Vibrating Wire Sonde Compared to a Ground-Based Microwave Radiometer." Atmospheric Research 149,77-87(2014). DOI: 10.1016/j.atmosres.2014.05.026.
2"Wire Sensors Alert to Dangerous Conditions in the Clouds" NASA Spinoff, 2017.

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