The NCAR/EOL Research Aviation Facility has recently completed a review and upgrade of its existing algorithms for data processing to incorporate recent improvements that have become available for specific instruments. HIPPO-4 LRT data have been reprocessed and rereleased with these new upgrades. For more info see the Appendix to HIPPO-IV Project Manager’s Report: Reprocessing

This update contains corrected 2DC data (variable names ending in _LWIO) from processing introduced in Version 2.0. No other data has been changed. It was discovered that all particles in a single buffer got time-stamped with the data-system time tag of the end off the buffer. For concentrations above 5-10/L, or when in heavy cloud, the system writes multiple buffers per second so the time-stamp will be very close to accurate. When a buffer spans multiple seconds, all the particles were being binned to the second of the end time-stamp for the buffer. This has now been corrected so data is spread across the time-period of the buffer correctly.

This version also uses exact circle fitting for measuring particle size and limits accepted particles to center-in images.