  This paper presents a novel deep-learning-based approach to improve
localizing radar measurements against lidar maps. Although the state of the art
for localization is matching lidar data to lidar maps, radar has been
considered as a promising alternative. This is largely due to radar being more
resilient against adverse weather such as precipitation and heavy fog. To make
use of existing high-quality lidar maps, while maintaining performance in
adverse weather, it is of interest to match radar data to lidar maps. However,
owing in part to the unique artefacts present in radar measurements,
radar-lidar localization has struggled to achieve comparable performance to
lidar-lidar systems, preventing it from being viable for autonomous driving.
This work builds on an ICP-based radar-lidar localization system by including a
learned preprocessing step that weights radar points based on high-level scan
information. Combining a proven analytical approach with a learned weight
reduces localization errors in radar-lidar ICP results run on real-world
autonomous driving data by up to 54.94% in translation and 68.39% in rotation,
while maintaining interpretability and robustness.
