Phoenix LiDAR Systems User Manual
  • Welcome
  • SpatialExplorer 8 & 9
    • Introduction
    • Installation
      • System Requirements
      • SpatialExplorer-Compatibility
      • Licensing
      • Change Log
    • User Interface
      • Windows
        • AGL Oracle
        • Classify On Selection
        • Coordinate Reference System
        • Corrections
        • Main View
        • Picks
        • Messages
        • Mission Guidance
        • Photo Viewer
        • Project
          • Rover
            • Cameras
              • Camera Acquisition Settings
              • Camera Calibration Settings
              • Camera Processing Settings
              • Camera Tools
                • Load sensor transform/extrinsics from file
                • Calibrate Sensor Manually
                • Edit Receptor Masks
            • IMU
            • GNSS
            • Lidars
              • Lidar Acquisition Settings
              • Lidar Calibration Settings
              • Lidar Processing Settings
              • Lidar Tools
                • Load sensor transform/extrinsics from file
          • Reference Stations
          • Flightplans
          • Geometry
            • Modifying Geometries
          • Grid
          • Ground Control
          • Images
          • Intervals
          • Trajectories
          • Pointclouds
          • Terrains
        • Project Player
        • Sensors
        • SLAM
          • SLAM Processing Profile
        • System Monitor
      • Toolbars
        • File
        • View
        • Selection
          • Cloud Script Tool
        • Workflow
          • NavLab Embedded
            • Processing Options
            • Estimating Primary Antenna Lever Arm
          • Create Intervals
          • Disambiguate Lidar Ranging
          • Create Cloud
          • LiDARSnap
            • Sensor Calibration
            • Trajectory Optimization
              • Aerial Trajectory Optimization
              • Mobile Trajectory Optimization
            • Ground Control with LiDARSnap
              • Vertical Only Adjustment
              • Full Adjustment
            • LiDARSnap Tuning and Parameters
            • Control Point Clouds
            • Example: Optimizing Data from Multiple Scans
          • CameraSnap
            • Auto-detect without review
            • Auto-detect with manual review
            • Manually-Created Matches
            • CameraSnap Reports
          • Colorize Cloud
          • Align to GCPs
            • Adjusting Automatically to GCPs (Vertical Only)
            • Manual Adjustment (Horizontal and Vertical)
          • Reports
          • Export
        • Analytics
          • Classify
            • Classify By Class
            • Classify Noise
            • Classify Statistical Outliers
            • Classify Ground
            • Classify Powerlines
            • Classify Moving Objects
          • Create
            • Create Maps
            • Create Floorplans
            • Create Contours
            • Create Mesh
            • Compute Normals
            • CloudClean
          • Calculate Distance
          • Measure
            • Std. Dev. Along Surface Normal
            • Surface Area and Point Density
            • Volume
          • Compute SOCS
        • LiDARMill
          • Positions
          • Manage Grids
          • View GNSS Antennas
        • Rover
          • Connect to Rover
          • Disconnect from Rover
          • Rover Settings and Profiles
            • Navigation System
            • Sensors
            • Camera Settings
            • LiDAR Settings
          • Shutdown Rover
        • Tools
          • Navigation
            • Plot Trajectories
          • Camera
            • Edit Camera Events
            • Create Camera Sessions from Data
          • Licensing
          • Create Transformation...
    • Workflows
      • Data Processing Workflows
        • Airborne Lidar Processing
        • Mobile Lidar Processing
        • Backpack and Pedestrian Lidar Processing
        • SLAM Lidar Processing
        • LAZ Processing
        • Field Data Check
    • FAQs
  • LiDARMill Cloud
    • Introduction
    • Login/Register
      • User management
    • Quick Start Guide
    • Overview
    • Post Processing Workflow
      • Create New Project
        • Details
        • Project Reference Setup
        • Summary
      • Create New Mission
        • Uploading a SpatialExplorer Mission
        • Uploading a RECON Mission
        • Uploading a Pointcloud Processing Mission
      • Adding Reference Station Data
      • Adding Ground Control Points and Polygons
        • Ground Control Points (GCPs)
        • Polygons
      • Processing Tools
        • NavLab Pipeline
        • Spatial Fuser Pipeline
        • Pointcloud Optimization Pipeline
      • Cloud Viewer
      • Additional Tabs
    • FAQs
  • FlightPlanner
    • Introduction
    • User Interface
      • FlightPlanner Interface Tools
        • Change Theme
        • Feedback, Help, and Changelog
        • Flight Info
        • Delete All
        • Measurement and Reset View
        • Upload Google KMZ file and Delete All KMLs
        • Take off Location
        • Reverse Waypoint Order, Undo, and Auto Update mission flightlines on setting change
        • Address Search
    • Workflow
      • Missions Library
      • Basic UAS LiDAR Mission Planning (FP 9.0)
      • Mission Type
    • Overlap
    • FAQs
  • Hardware and Interfaces
    • Warnings and Safety Notices
      • LiPo Battery Safety
        • General Guidelines and Warnings
        • Pre-Charging Guidelines
        • Charging Process Guidelines
        • Storage/Transportation Guidelines
        • Battery Care Guidelines
      • Laser Safety
        • Class 1 Lasers
        • VUX-240 Laser Safety
      • Aircraft/Rover Operational Safety
    • Connecting and Interfacing with Phoenix Lidar Systems
      • Connect via Rover's Web Interface
      • Connecting via SpatialExplorer
        • Base Station (Notebook) Setup
          • Configure Windows
            • Disable Automatic Updates
            • Change Active Hours
            • Install Latest NVIDIA Drivers
          • Modify Hosts File
          • Wired Ethernet Network Card Setup
          • Install Software Tools
            • 7-Zip
            • Filezilla
            • Teamviewer
            • PuTTY
            • NovAtel Connect and NovAtel Convert4
        • Connect to Rover
          • Connect to Rover as a UDP Client
            • Connect via Wi-Fi
            • Connect via Ethernet
              • Connect via 900 MHz Radio
            • Connect Via Ground-Station-Wi-Fi (Groove)
              • Connect via Ground Station Wi-Fi (Bullet M5)
          • Connect to Rover using a Serial Port
          • Connect to Rover via Connection Service
            • Connect via Cellular
        • User Interface
          • Settings
            • Rover Settings
              • General
              • Navigation System
              • Network
            • Local Settings
          • System Monitor
          • Sensors
          • Satellites
      • Downloading Rover Data
        • Log Files
      • Updating Rover
    • NavBox
      • FLEXPack
        • Specifications
        • Ports and User Elements
        • Status LED
        • Using the CPU button
        • Preparing the System
        • Recording Data
        • Questions & Troubleshooting
      • Air
        • Specifications
        • Ports and User Elements
        • Status LED
        • Using the CPU Button
        • Preparing the System
        • Recording Data
        • Questions & Troubleshooting
      • Scout
        • Specifications
        • Ports and User Elements
        • Using the CPU/Sensor Button
        • Preparing the System
        • Recording Data
        • Questions & Troubleshooting
      • RECON Series
      • Alpha 3
        • Ports and User Elements
        • IMU-32/IMU-33/IMU-34
        • IMU-41/IMU-52
        • IMU-14/IMU-27
    • Camera
      • Sony Mirrorless Cameras
        • Specifications
        • Camera Settings
        • A7R4 Warning Messages
      • A7R4-Lite
        • Sony A7R4-Lite SD card folder setup procedure
      • A6K-Lite Camera
        • Highlights
        • Specifications
        • Warnings
        • Ports and User Elements
        • Status & Activity LED
        • Settings Wheel
        • Mounting
        • Powering ON the Camera - Self-Check
        • Operating with Spatial Explorer
          • Changing the Trigger Interval / Distance
          • Initial Camera Setup
          • Dual A6K-Lite Setup
        • Changing Camera Settings
        • Troubleshooting
      • Ladybug5+ and LadybugCapPro
        • Pre-Procedure
        • Data Acquisition
    • Lidars
      • Real-Time Point Clouds and MTA Disambiguation
    • Inertial Navigation System
      • Orientation and Offsets
        • IMU
        • GNSS Antennas
        • LiDARs and Cameras
      • Wheel Sensor
    • Miscellaneous Hardware
      • Mobile Roof Rack
        • RFM2-Dual LiDAR Mobile Accessory
      • Backpack Lidar Mount
        • Backpack Telescoping Boom
      • Wi-Fi Range Extenders
      • Accessories
        • Cables
          • SMB to SMA GPS Antenna Cable
          • MCX to RP-SMA WiFi Antenna Cable
          • LiDAR / Camera Cable
          • micro USB to USB Type A Female Cable
          • RJ45 Ethernet Cable
          • HDMI Cable Type D to Type A
          • SMA to TNC Ground Mount GNSS Antenna Cable
          • 7.5” Rover GPS Antenna Cable
          • 24” Rover GPS Antenna Cable
        • Power Supply Parts
          • Power Splitter Cable
          • AC Power Supply
          • XT30 3" Extension Cable
          • XT60 Female to XT30 Male Adapter
          • XT60 Male to XT30 Female Adapter
          • XT60 Female to EC5 Male
          • XT60 Extension Cable
        • Antennas
          • Rover GNSS Antenna
          • UHF Rubber Duck Antenna
          • Ground Mount GNSS Antenna
          • Bullet Long Range Module
          • Omni 12dBi Antenna for Bullet Module
          • Rover 5.8 GHz Wi-Fi Antenna RP-SMA
        • Other Components
          • LiDAR/IMU Cable
          • LiDAR Cable
          • IMU Cable
          • AL3 Power Cable with Integrated Splitter
          • EC5 to XT60 Adapter Cable
          • LiPo with EC5 Connector
          • LiPo Charger
          • 5.8 GHz Directional Panel Antenna
          • TNC 90 Degree Adapter
        • Miscellaneous
          • USB Drive
          • USB to Ethernet Adapter
          • Suction Cups w/ Clamps
          • Multi-Tool
          • SMA Wi-Fi Terminator
          • LiDAR Sensor Cover
          • LiPo Guard Battery Bag
          • Cable Accessories Bag
          • Storm Case
          • Foam Divider
  • Data Acquisition and UAV Piloting
    • Flight Planning
      • UAS LiDAR Hot Swapping
    • UAV Data Acquisition
    • Mobile Acquisition
    • Backpack Acquisition
      • Ranger FLEX Initialization and Acquisition Workflow
      • Recon XT Initialization and Acquisition Workflow
    • SLAM Acquisition
    • Navigation System Configuration
      • Navigation System Basics
      • Real-Time and Post-Processing Differences
      • Further Reading
        • GPS Time Status
        • Navigation Procedures
        • IMU Alignment
        • Navigation System Stabilization
    • RECON UAV Acquisition
    • RECON Series Quick Start Guides
      • RECON-XT M300/M350
      • RECON-XT-A FreeFly Astro
      • RECON-A
    • Calibration Flight Strategy
    • Acquisition FAQs
    • Post Acquisition Checks
  • MissionGuidance
    • Introduction
    • Flightplans
    • Heightmaps
    • Setup
    • Operations
  • GNSS Hardware and Ground Control
    • Reference Stations
    • Downloading Reference Station Data
    • Ground Control - Best Practices
    • Stonex S-900 and Cube-A
      • Cube-A project set up
      • Configure base station
        • Configuring Harxon HX-DU8608D radio
      • Configure rover
      • Surveying ground control points
      • Post processing
        • Post processing base station observations
        • Change base coordinates to a post processed position
        • Export points from Cube-A
  • Reports
    • Processing Report
    • Project Report
    • Trajectory Report
  • 3rd Party Software Documentation
    • Bathymetric LiDAR Processing in RiProcess
      • Creating a Project in RiProcess
        • Adding a Navigation Device
        • Adding a Trajectory
        • Adding a Scanner
        • Adding a Camera
        • Adding Control Objects
        • Processing Parameters
          • Exponential Decomposition
          • Page
        • Adding Records
      • Data Processing Wizard
      • Visualize Data
      • RiPrecision
      • RiHydro Workflow
    • RiParameter
    • TerraSolid and Spatix Install
    • Orthomosaic Production with Pix4D
    • InertialExplorer Desktop 8.70 - 8.90 Processing
    • Hyperspectral Data Processing
    • SDCImport Filter Options
      • MTA (Multiple Time Around)
      • Region of Interest
  • Image Processing using PhaseOne IXCapture
  • General FAQ
    • Accuracy Standards & Quantification
      • Precision
      • Relative Accuracy
      • Absolute Accuracy
      • Further Considerations
    • Mapping Terms and Definitions
    • Abbreviations
    • Examples: How to ensure accurate Georeferencing of Trajectories and Pointclouds
      • Example 1: Static Datum
      • Example 2: Dynamic Datum
    • Clock bias adjustment
    • General FAQs
  • Legacy Documentation
    • Offsets, Rotations, and Reference Frames: SpatialExplorer Version 4-7
    • Legacy TerraSolid Documentation
    • Legacy SpatialExplorer Documentation
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On this page
  • SLAM Initialization
  • SLAM Scanning Technique
  • RECON-XT SLAM Video
  1. Data Acquisition and UAV Piloting

SLAM Acquisition

PreviousRecon XT Initialization and Acquisition WorkflowNextNavigation System Configuration

Last updated 1 year ago

SLAM Initialization

While most SLAM data is captured indoors, without GNSS reception, it is important to begin your data acquisition outside to allow the system to receive GPS time and record an initial position to globally reference your indoor scan. Spend at least 2 minutes outdoors in an open environment at the beginning of the scan to obtain quality GNSS data.

Georeferencing will be more robust if your scan has several periods of GNSS reception at different places intermixed with periods of indoor scanning.

Scout Systems

  1. Power on the rover outside.

  2. Connect to the system via the , using a mobile phone or tablet.

  3. Press Start Rover, and wait for Time status to become FineSteering.

  1. Capture will be enabled after the Time status FineSteering is achieved. This can be confirmed in Messages, where the message "GNSS determined accurate time, allowing capture to be enabled." will appear.

  1. Proceed indoors and scan.

  2. The Time status can degrade afterwards (e.g. after entering a building). This will not impact the ability to start capturing data when FineSteering has been achieved at least once after Rover has started.

RECON Systems

  1. Power on the system outside and connect to the web interface.

  2. Set the camera trigger interval to 120 seconds if you are not interested in recording camera data.

  3. Ensure the antenna offsets and IMU orientation are correct for a SLAM setup.

  4. Allow the system to track satellites for approximately 2 minutes.

  5. Click "Start recording" to allow the system to begin recording lidar and navigation data.

  6. Proceed indoors to scan.

SLAM Scanning Technique

Scanning Motion

Keep the unit steady and with a good view of it's surroundings for the first 10 seconds once you see LIDAR data come in. This is to build a good initial map for SLAM to orient itself in. As you move indoors, move the unit steady and try to cover all surfaces.

Continue performing a smooth motion while you collect LiDAR data. Be aware that LiDAR pulses may reflect off of glass windows and doors, resulting in an undesirable georeferencing of the lidar pulse.

Small rooms may require extra scanning, as many of the LiDAR pulses will not register as a return due to the minimum range of the scanner; with the Velodyne VLP-16 and Hesai XT32, this minimum range is about 1 meter. As well, ceilings and floors will require more deliberate scanning than features at eye-level, as the field of view on the LiDAR scanner is narrow and will not typically receive many of these points.

Loop Closure

Loop closure refers to the SLAM algorithm adjusting it's current map and trajectory based on the appearance of a feature that was previously scanned. As you scan in a GNSS denied environment, the position as determined by SLAM drifts from the true position. Loop closure can effectively reduce this drift by adjusting the current map to a previous map which was created with less drift.

Consider loop closure when scanning. When scanning large, open, indoor spaces, try to walk in a circle, so that the end of the scan corresponds to the beginning of the scan. If you scan a hallway or mostly linear indoor space, walk down and back through the hallway.

Other best practices:

  • Scan when the building is mostly unoccupied, so that people do not appear in the scan.

  • Exit the building when feasible to obtain additional GNSS fixes and limit trajectory drift.

  • Open doors prior to the scan. This way the "state" of the door (open or closed) is fixed during the scan and the door does not appear as both opened and closed in the point cloud.

  • Scan with a friend! It's helpful to have someone who can open doors prior to you entering the space, as well as close doors when you exit the space.

  • If you plan on matching your SLAM scan to an aerial scan, try to get good lidar coverage on features that are visible in the aerial scan. For instance, if you exit the building to get a GPS fix, try to get some lidar coverage on the building walls and roof, if possible.

  • At all times, and especially at the starting location, the LiDAR unit should have good visibility of the world around it. Avoid confined spaces. Do not occlude the LiDAR unit's field of vision.

  • The recommended position for mounting the LiDAR is straight, i.e. such the unit has a horizontal 360° view of the surroundings. If acquisition is performed by carrying, the LiDAR may be gently swung in order to increase coverage.

  • Either completely avoid revisiting the same areas, or revisit them thoroughly, making sure there is decent overlap of the same area between the old and the new parts of the trajectory.

RECON-XT SLAM Video

Loop closure used to mitigate trajectory drift.
Loop closure used to mitigate trajectory drift.
web interface