Date of Award




Document Type


Degree Name

Doctor of Philosophy (PhD)


Department of Atmospheric and Environmental Sciences

Content Description

1 online resource (xxvi, 270 pages) : illustrations (some color)

Dissertation/Thesis Chair

Lee C Harrison

Committee Members

Kristen L Corbosiero, Bryan Tang, Ryan Torn


Convection, Dropsondes, Instrumentation, Pitot-static, Tropical cyclones, Vertical velocity, Dropwindsondes, Vertical wind shear, Air speed, Air-speed indicators

Subject Categories

Atmospheric Sciences | Meteorology


The earliest iterations of dropsondes in the 1960's obtained vertical velocity by measuring the geometric fall speed of the dropsonde and the true airspeed (TAS) of the dropsonde from a pitot-static. The vertical velocity errors from this methodology were claimed to be ±1 m s-1. Subsequent dropsonde iterations used various forms of the drag force equation to obtain vertical velocity. The accuracy of these drag force-based measurements, however, are also quite large at ±1–2 m s-1. In this dissertation, an attempt is made to improve vertical velocity errors by revisiting and revising the pitot-static-derived TAS methodology on the eXpendable Digital Dropsondes (XDDs). The primary goals were to decrease errors to ±0.1 m s-1 and introduce a prototype for a highly accurate vertical velocity dropsonde for use in tropical cyclone (TC) research.