Recent advances in robotics have underscored the critical role of colorized point clouds in enhancing environmental perception accuracy. However, conventional multisensor fusion Simultaneous Localization and Mapping (SLAM) systems typically employ all available images indiscriminately for point cloud colorization, resulting in suboptimal outcomes with blurred textures. Notably, achieving precise texture-togeometry alignment remains a challenge despite the availability of accurate pose estimation. This study introduces RISED, an advanced colorized mapping system that tackles this challenge from two perspectives: projection accuracy and distribution uniformity. For projection accuracy, we analyze the influence of camera poses on colorization and carefully select the optimal viewpoint to minimize errors. Regarding distribution uniformity, point cloud densification is applied to eliminate LiDAR scanning traces. Furthermore, a novel evaluation method is introduced to provide comprehensive assessment of colorized point clouds, filling a gap in this field. Experimental results show that our method outperforms traditional approaches in RGB-colorized mapping. Specifically, our method achieves notable improvements in projection accuracy (55.2 %), geometric accuracy (63.1 %), and surface coverage (30.8 %).

In this paper, we propose a continuous-time-based LiDAR-inertial-vehicle odometry method, which can tightly fuse the data from Light Detection And Ranging (LiDAR), inertial measurement units (IMU), and vehicle measurements. The lateral acceleration constraint is further added to trajectory estimation to make the estimated trajectory follow the motion characteristics of vehicles. In addition, since vehicle model parameters vary with different motion conditions and tyre pressure, we estimate vehicle correction factors that rectify changes in vehicle model parameters online, and also analyze the observability of these vehicle correction factors. In experiments, the proposed method is evaluated and compared with state-of-the-art methods in the public dataset. The experimental results show that the proposed method achieves more accurate results in all sequences since we add additional sensor measurements and utilize the characteristic of vehicle motion to restrict the trajectory estimation. The ablation study also proved the effectiveness of continuous-time representation, online correction factor estimation, and incorporation of lateral acceleration constraint.

In this paper, we introduce a novel approach to fine-grained cross-view geo-localization. Our method aligns a warped ground image with a corresponding GPS-tagged satellite image covering the same area using homography estimation. We first employ a differentiable spherical transform, adhering to geometric principles, to accurately align the perspective of the ground image with the satellite map. This transformation effectively places ground and aerial images in the same view and on the same plane, reducing the task to an image alignment problem. To address challenges such as occlusion, small overlapping range, and seasonal variations, we propose a robust correlation-aware homography estimator to align similar parts of the transformed ground image with the satellite image. Our method achieves sub-pixel resolution and meter-level GPS accuracy by mapping the center point of the transformed ground image to the satellite image using a homography matrix and determining the orientation of the ground camera using a point above the central axis. Operating at a speed of 30 FPS, our method outperforms state-of-the-art techniques, reducing the mean metric localization error by 21.3\% and 32.4\% in same-area and cross-area generalization tasks on the VIGOR benchmark, respectively, and by 34.4\% on the KITTI benchmark in same-area evaluation.