--- title: Best Practices for Collecting SLAM Data Under an Underpass or Bridge description: When collecting SLAM data with a ROCK LiDAR unit in challenging locations like underpasses or bridges, it’s essential to follow specific steps for optimal data quality. This guide outlines the recommended approach --- [Skip to content](https://learn.rockrobotic.com/best-practices-for-collecting-slam-data-under-an-underpass-or-bridge#main-content) English Show submenu for translations ![ROCK-robotic-community-logo.png\]](https://learn.rockrobotic.com/hs-fs/hubfs/ROCK-robotic-community-logo.png?width=250&height=50&name=ROCK-robotic-community-logo.png) - [ROCK Customer Support](https://www.rockrobotic.com/support/) Open main navigation Close main navigation - [ROCK Customer Support](https://www.rockrobotic.com/support/) - English Show submenu for translations - [www.rockrobotic.com](https://www.rockrobotic.com/) [www.rockrobotic.com](https://www.rockrobotic.com/) Hello. How can we help you? - There are no suggestions because the search field is empty. 1. [ROCK Knowledgebase](https://learn.rockrobotic.com/?hsLang=en) 2. [ROCK SLAM](https://learn.rockrobotic.com/rock-slam?hsLang=en) 3. [SLAM Data Collection](https://learn.rockrobotic.com/rock-slam?hsLang=en#slam-data-collection) October 30, 2024 # Best Practices for Collecting SLAM Data Under an Underpass or Bridge ## When collecting SLAM data with a ROCK LiDAR unit in challenging locations like underpasses or bridges, it’s essential to follow specific steps for optimal data quality. This guide outlines the recommended approach ### Preparing for SLAM Data Collection To collect SLAM data efficiently, ensure the following: - Use a compatible device like the R3 Pro V2 LiDAR. - Familiarize yourself with the [**one-button method**](https://learn.rockrobotic.com/how-to-use-the-1-button-method-for-slam-on-r3-pro?hsLang=en) for easy operation. - Have an **open sky environment** as you start and finish the capture for better GNSS data.  ### Step-by-Step SLAM Data Capture Follow these steps to ensure precise data collection: 1. **Position and Activate**: Start with a **30-second static capture** in an open area before moving towards the underpass. This helps in initializing the GNSS signal for better satellite reception. 2. **Begin Walking**: Keep the device steady and positioned to avoid obstructions from the bridge structure. Aim to hold it slightly above head height for an unobstructed scan. 3. **Slow Walk and Tilt Technique**: - Walk slowly along **one side** of the underpass. - Use a subtle **tilt** to cover the top of the underpass, capturing as much detail as possible. - **Repeat** this process on the opposite side for comprehensive data coverage. 4. **Ensure Loop Closure**: Return to your starting point to enhance data accuracy through loop closure. Check out additional [**loop closure tips.**](https://learn.rockrobotic.com/how-to-capture-and-process-slam-data-on-the-r3-pro?hsLang=en) **Pro Tip**: Small tilts during the capture create a "painting" effect, covering areas that might otherwise be missed. However, avoid excessive tilting to prevent IMU issues. ### Finalizing the Capture After collecting data: 1. Perform a **final static capture** for another 30 seconds. 2. Use the one button method to s**top data collection.** 3. **Turn off** the device. --- Related Resources for Further Information - Unlock LiDAR Access and Get Academy Training - SLAM Data Processing in Rock Desktop - R3 Pro SLAM Colorization Setup This approach to SLAM data collection provides structured coverage under difficult conditions, helping you capture complete, accurate data for all underpass or bridge projects. - [ROCK R3 Pro](https://learn.rockrobotic.com/rock-r3-pro?hsLang=en#main-content) - [Setup](https://learn.rockrobotic.com/rock-r3-pro?hsLang=en#setup) - [Data collection](https://learn.rockrobotic.com/rock-r3-pro?hsLang=en#data-collection) - [Updates and Maintenance](https://learn.rockrobotic.com/rock-r3-pro?hsLang=en#updates-and-maintenance) - [Mobile Mount](https://learn.rockrobotic.com/rock-r3-pro?hsLang=en#mobile-mount) - [Photogrammetry](https://learn.rockrobotic.com/rock-r3-pro?hsLang=en#photogrammetry) - [ROCK Desktop](https://learn.rockrobotic.com/rock-desktop?hsLang=en#main-content) - [Desktop Processing](https://learn.rockrobotic.com/rock-desktop?hsLang=en#desktop-processing) - [Using ROCK Desktop](https://learn.rockrobotic.com/rock-desktop?hsLang=en#using-rock-desktop) - [Desktop License](https://learn.rockrobotic.com/rock-desktop?hsLang=en#desktop-license) - [Desktop Support](https://learn.rockrobotic.com/rock-desktop?hsLang=en#desktop-support) - [Releases](https://learn.rockrobotic.com/rock-desktop?hsLang=en#releases) - [ROCK Cloud](https://learn.rockrobotic.com/rock-cloud?hsLang=en#main-content) - [Overview](https://learn.rockrobotic.com/rock-cloud?hsLang=en#overview) - [Project Data](https://learn.rockrobotic.com/rock-cloud?hsLang=en#project-data) - [Managing Projections](https://learn.rockrobotic.com/rock-cloud?hsLang=en#managing-projections) - [ROCK Cloud Tools](https://learn.rockrobotic.com/rock-cloud?hsLang=en#rock-cloud-tools) - [Processing](https://learn.rockrobotic.com/rock-cloud?hsLang=en#processing) - [Deliverables & Exports](https://learn.rockrobotic.com/rock-cloud?hsLang=en#deliverables-exports) - [General](https://learn.rockrobotic.com/rock-cloud?hsLang=en#general) - [ROCK SLAM](https://learn.rockrobotic.com/rock-slam?hsLang=en#main-content) - [SLAM Hardware](https://learn.rockrobotic.com/rock-slam?hsLang=en#slam-hardware) - [SLAM Data Collection](https://learn.rockrobotic.com/rock-slam?hsLang=en#slam-data-collection) - [ROCK Colorized SLAM Dock V2](https://learn.rockrobotic.com/rock-slam?hsLang=en#rock-colorized-slam-dock-v2) - [SLAM Data Alignment](https://learn.rockrobotic.com/rock-slam?hsLang=en#slam-data-alignment) - [ROCK Base Station](https://learn.rockrobotic.com/rock-base-station?hsLang=en#main-content) - [ROCK Base Setup](https://learn.rockrobotic.com/rock-base-station?hsLang=en#rock-base-setup) - [ROCK Network](https://learn.rockrobotic.com/rock-base-station?hsLang=en#rock-network) - [Base Data](https://learn.rockrobotic.com/rock-base-station?hsLang=en#base-data) - [ROCK Deliverables](https://learn.rockrobotic.com/rock-deliverables?hsLang=en#main-content) - [Deliverables](https://learn.rockrobotic.com/rock-deliverables?hsLang=en#deliverables) - [Ordering](https://learn.rockrobotic.com/rock-deliverables?hsLang=en#ordering) - [Processing](https://learn.rockrobotic.com/rock-deliverables?hsLang=en#processing) - [General Knowledge](https://learn.rockrobotic.com/general-knowledge?hsLang=en#main-content) - [ROCK](https://learn.rockrobotic.com/general-knowledge?hsLang=en#rock) - [Drones](https://learn.rockrobotic.com/general-knowledge?hsLang=en#drones) - [GPS / GNSS](https://learn.rockrobotic.com/general-knowledge?hsLang=en#gps-gnss) - [LiDAR](https://learn.rockrobotic.com/general-knowledge?hsLang=en#lidar) - [Surveying](https://learn.rockrobotic.com/general-knowledge?hsLang=en#surveying) - [ROCK R2A & R360](https://learn.rockrobotic.com/rock-r2a-r360?hsLang=en#main-content) - [Hardware](https://learn.rockrobotic.com/rock-r2a-r360?hsLang=en#hardware) - [Data Collection](https://learn.rockrobotic.com/rock-r2a-r360?hsLang=en#data-collection) - [Aerial Data Capture](https://learn.rockrobotic.com/rock-r2a-r360?hsLang=en#aerial-data-capture) - [Creating Orthomosaics](https://learn.rockrobotic.com/rock-r2a-r360?hsLang=en#creating-orthomosaics) - [What's New](https://learn.rockrobotic.com/whats-new?hsLang=en) - [Sales](https://learn.rockrobotic.com/sales?hsLang=en) - [ROCK Ultra](https://learn.rockrobotic.com/rock-ultra?hsLang=en#main-content) - [Setup](https://learn.rockrobotic.com/rock-ultra?hsLang=en#setup) - [Data Collection](https://learn.rockrobotic.com/rock-ultra?hsLang=en#data-collection) - [Settings](https://learn.rockrobotic.com/rock-ultra?hsLang=en#settings) [![Chill listening crop-3](https://learn.rockrobotic.com/hs-fs/hubfs/ROCK-robotic-community-logo-1.png?width=120&height=24&name=ROCK-robotic-community-logo-1.png "Chill listening crop-3")](http://rockrobotic.com) rockrobotic.com Help Center Copyright © 2026, ROCK Robotic Inc.