  High accuracy and dynamic range have been some of the most prominent
challenges when it comes to fine-scale turbulence measurements. The current
commercial LDA processors, which perform the signal processing of Doppler
bursts directly using hardware components, are essentially black boxes and in
particular are renown for suffering from practical limitations that reduce the
measurement reliability and accuracy. A transparently functioning novel LDA,
utilizing advanced technologies and up-to-date hardware and software has
therefore been developed to enhance the measurement quality and the dynamic
range. In addition, the self-developed software comes with a highly flexible
functionality for the signal processing and data interpretation. The LDA setup
and the combined forward/side scattering optical alignment (to minimize the
effective measuring volume) are described first, followed by a description of
the signal processing aspects. The round turbulent jet has been used as the
test bed since it presents a wide range of degree of difficulty for the LDA
processor (accuracy, dynamic range etc.) across the different radial distances
and downstream development. The data are diagnosed for dynamic range in
residence and interarrival times, and compared to a typical hardware driven
processor. The radial profiles of measured mean streamwise velocity and
variance agree well with previous studies of the round jet. The spatial
turbulent kinetic energy spectra in the fully developed region perfectly match
the expected (and in this region well established) -5/3 power law even for the
largest measured distances from the centerline (where shear and turbulence
intensity are significant).
