> For the complete documentation index, see [llms.txt](https://docs-7.phoenixlidar.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs-7.phoenixlidar.com/lidarmill-desktop/workflow-kk/lidarsnap-v4.md).
# LiDAR Calibration and Optimization
## LiDARSnap
LiDARSnap is used to optimize lidar point clouds by calibrating sensors and optimizing trajectories. This helps improve relative optimize alignment from different flight lines or from different times. LiDARSnap can also be used to make variable adjustments to control (rubber-sheet adjustments) if enabled.
LiDARSnap has three preset functions:
[**Aerial Calibration:**](/lidarmill-desktop/workflow-kk/lidarsnap-v4/sensor-calibration.md) Optimizes the lidar sensor's orientation and intrinsic parameters to better align data from different intervals. This preset makes adjustments that apply globally to a data set, and cannot resolve variable trajectory error. For best results, only use this tool on a [boresight calibration dataset](https://docs.phoenixlidar.com/rover/theory-and-workflow/boresighting-flight-strategy#uav-flight-plan).
[**Aerial Trajectory Optimization:**](/lidarmill-desktop/workflow-kk/lidarsnap-v4/trajectory-optimization/airborne-trajectory-optimization.md) Improves point cloud accuracy for aerial datasets by reducing relative errors between overlapping swaths of aerial lidar data that stem from trajectory inaccuracies (position and orientation errors).
[**Mobile Trajectory Optimization:**](/lidarmill-desktop/workflow-kk/lidarsnap-v4/trajectory-optimization/mobile-trajectory-optimization.md) Similar to the aerial trajectory optimization preset, but more aggressive when optimizing and uses a spline-style adjustment.
Point cloud changing from an uncalibrated cloud to a fully calibrated cloud colored by elevation
## Video Walkthrough
In this video, we cover the LiDARSnap 4 module.
{% embed url="" %}