  We introduce a novel method for oriented place recognition with 3D LiDAR
scans. A Convolutional Neural Network is trained to extract compact descriptors
from single 3D LiDAR scans. These can be used both to retrieve near-by place
candidates from a map, and to estimate the yaw discrepancy needed for
bootstrapping local registration methods. We employ a triplet loss function for
training and use a hard-negative mining strategy to further increase the
performance of our descriptor extractor. In an evaluation on the NCLT and KITTI
datasets, we demonstrate that our method outperforms related state-of-the-art
approaches based on both data-driven and handcrafted data representation in
challenging long-term outdoor conditions.
