  Barchans are dunes commonly found in dune fields on Earth, Mars and other
celestial bodies, where they can interact with each other. This article
concerns experimental data for the flow over subaqueous barchans that are
either isolated or interacting with each other. The experiments were carried
out in a transparent channel of rectangular cross section in which turbulent
water flows were imposed over either one single or a pair of barchans. The
instantaneous flow fields were measured by using a low-frequency PIV (particle
image velocimetry) and high-frequency PTV (particle tracking velocimetry). From
the PIV and PTV data, the mean flow, trajectories, and second-order moments
were computed, which are included in the datasets described in this paper,
together with raw data (images), instantaneous fields, and scripts to process
them. The datasets can be reused for benchmarking or for processing new images
generated by other research groups.
