LIORNet: Self-Supervised LiDAR Snow Removal Framework for Autonomous Driving under Adverse Weather Conditions
Authors: Ji-il Park, Inwook Shim
Organizations: Ministry of National Defense, 22, Itaewon-ro, Yongsan-gu, Seoul, Republic of Korea. · Department of Smart Mobility Engineering, Inha University, Republic of Korea.
LiDAR sensors provide high-resolution 3D perception and long-range detection, making them indispensable for autonomous driving and robotics. However, their performance significantly degrades under adverse weather conditions such as snow, rain, and fog, where spurious noise points dominate the point cloud and lead to false perception. To address this problem, various approaches have been proposed: distance-based filters exploiting spatial sparsity, intensity-based filters leveraging reflectance distributions, and learning-based methods that adapt to complex environments. Nevertheless, distance-based methods struggle to distinguish valid object points from noise, intensity-based methods often rely on fixed thresholds that lack adaptability to changing conditions, and learning-based methods suffer from the high cost of annotation, limited generalization, and computational overhead. In this study, we propose LIORNet, which eliminates these drawbacks and integrates the strengths of all three paradigms. LIORNet is built upon a U-Net++ backbone and employs a self-supervised learning strategy guided by pseudo-labels generated from multiple physical and statistical cues, including range-dependent intensity thresholds, snow reflectivity, point sparsity, and sensing range constraints. This design enables LIORNet to distinguish noise points from environmental structures without requiring manual annotations, thereby overcoming the difficulty of snow labeling and the limitations of single-principle approaches. Extensive experiments on the WADS and CADC datasets demonstrate that LIORNet outperforms state-of-the-art filtering algorithms in both accuracy and runtime while preserving critical environmental features. These results highlight LIORNet as a practical and robust solution for LiDAR perception in extreme weather, with strong potential for real-time deployment in autonomous driving systems.
Figures & tables
Fig. 1: Categorization by approach [ 8 ] . LIORNet shown at the center is the first attempt to unify all three strategies.
Fig. 2: Overall LIORNet framework: (a) data processing pipeline, (b) network architecture, and backbone configurations using (c) U-Net and (d) U-Net++.
Fig. 3: Visualization of conditional pseudo-label point updates. Candidate snow points are sequentially refined through intensity (Cond1), reflectivity (Cond2), edge (Cond3), and sparsity (Cond4) conditions resulting in the final pseudo-labeled snow points.
ID
UW
PP
DS
Precision
Recall (TPR)
FPR
FNR
IoU
1
X
X
X
0.379 ± 0.107
0.942 ± 0.088
0.265 ± 0.072
0.058 ± 0.088
0.368 ± 0.104
2
X
O
X
0.473 ± 0.136
0.961 ± 0.068
0.175 ± 0.049
0.039 ± 0.068
0.462 ± 0.132
3
X
X
O
0.402 ± 0.106
0.939 ± 0.093
0.240 ± 0.069
0.061 ± 0.093
0.389 ± 0.103
4
X
O
O
0.498 ± 0.132
0.958 ± 0.072
0.157 ± 0.046
0.042 ± 0.072
0.486 ± 0.128
5
20%
X
X
0.378 ± 0.104
0.941 ± 0.090
0.266 ± 0.074
0.059 ± 0.090
0.367 ± 0.101
6
20%
O
X
0.477 ± 0.133
0.960 ± 0.070
0.172 ± 0.048
0.040 ± 0.070
0.465 ± 0.129
TABLE I: Quantitative Evaluation of LIORNet under Different Configurations. Postprocess was applied with the theoretical snow sensing limit of 71.23m. (UW: Uncertainty-based Weighting, PP: Postprocessing, DS: Deep Supervision)
Fig. 4: False-positive snow data before and after applying the rule-based postprocessing (considering LiDAR height and the theoretical snow-sensing distance).
Fig. 5: Comparison of performance on the (A) WADS and (B) CADC datasets. (a) Raw, (b) DROR, (c) LIOR, (d) D-LIOR, (e) LiSnowNet, (f) LIORNet.
Method
Precision
Recall
F1-score
F3-score
F5-score
Runtime
ms
Hz
DROR
0.764 ± 0.021
0.745 ± 0.152
0.754
0.747
0.746
3505
0.3
LIOR
0.827 ± 0.027
0.908 ± 0.138
0.866
0.899
0.905
208.1
4.8
D - LIOR
0.918 ± 0.038
0.875 ± 0.125
0.896
0.879
0.877
115.6
8.7
LiSnowNet
0.951 ± 0.039
0.842 ± 0.167
0.893
0.852
0.846
4.98
201.0
LIORNet (U-Net)
0.379 ± 0.107
0.942 ± 0.088
0.541
0.820
0.891
21.39
46.8
TABLE II: Quantitative evaluation on the WADS dataset. Postprocess was applied using the optimal range of 20m.
Configuration
Precision
Recall
Baseline(Full)
0.672 ± 0.132
0.920 ± 0.114
- Intensity term (Cond1)
0.306 ± 0.094
0.951 ± 0.076
- Reflectivity term (Cond2)
0.401 ± 0.110
0.938 ± 0.092
- Edge term (Cond3)
0.195 ± 0.118
0.679 ± 0.136
- Sparsity term (Cond4)
0.387 ± 0.109
0.941 ± 0.090
- Penalty term (Cond5)
0.256 ± 0.099
0.962 ± 0.061
TABLE III: Ablation study on the contributions of each component. The study is conducted based on ID 4 in Table I .
Fig. 6: Performance evaluation on real-world data (a) Raw, (b) DROR, (c) LIOR, (d) D-LIOR, (e) LiSnowNet, (f) LIORNet.
Geoinformatics Group, Department of Civil Engineering, Indian Institute of Technology Kanpur, India · Department of Geodesy and Geomatics Engineering, University of New Brunswick, NB, Canada · Department of Engineering Technology & Industrial Distribution (ETID) of Texas A&M University