New developments in photon Doppler velocimetry

E A Moro

doi:10.1088/1742-6596/500/14/142023

Abstract

Photon Doppler velocimetry (PDV) has made the transition among many experimental groups from being a new diagnostic to being routinely fielded as a means of obtaining velocity data in high-speed test applications. Indeed, research groups both within and outside of the shock physics community have taken note of PDV's robust, high-performance measurement capabilities. As PDV serves as the primary diagnostic in an increasing number of experiments, it will continue to find new applications and enable the measurement of previously un-measurable phenomena. This paper provides a survey of recent developments in PDV system design and feature extraction as well as a discussion of new applications for PDV. More specifically, changes at the system level have enabled the collection of data sets that are far richer than those previously attainable in terms of spatial and temporal coverage as well as improvements over PDV's previously measurable velocity ranges. And until recently, PDV data have been analyzed almost exclusively in the frequency-domain; although the use of additional data analysis techniques is beginning to show promise, particularly as it pertains to extracting information from a PDV signal about surface motion that is not along the beam's axis.

Highlights

Introduction and background PhotonDoppler velocimetry (PDV) was introduced by Ted Strand in 2004 [1] and again in 2006[2]
Leapfrogged photon Doppler velocimetry Dolan et al of Sandia National Laboratory (SNL) recently demonstrated a technique they refer to as “leapfrogged Photon Doppler velocimetry (PDV)”, where several laser/photodetector pairs are used in parallel to increase PDV’s velocity range [18]
Multiplexed photon Doppler velocimetry (MPDV) is perhaps the biggest development to PDV in recent years, and it enables collection of data sets, whose spatial- and temporal-coverage during a dynamic test are unparalleled in optical velocimetry

Summary

Introduction

Introduction and background PhotonDoppler velocimetry (PDV) was introduced by Ted Strand in 2004 [1] and again in 2006[2]. MPDV makes use of multiplexing, both in the frequency-domain and in the time-domain, to combine several velocity histories (i.e., several probes’ measurements) onto a single digitizer channel. MPDV enables an eightfold increase in the number of probes allowed per digitizer, and this results in a denser spatial sampling of the target surface.

Results

Conclusion