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
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          • Rover
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                • 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
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        • Project Player
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        • SLAM
          • SLAM Processing Profile
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      • Toolbars
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        • 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
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        • Rover
          • Connect to Rover
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          • Rover Settings and Profiles
            • Navigation System
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          • Shutdown Rover
        • Tools
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          • 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
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      • Downloading Rover Data
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    • 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
  • Location Selection
  • UAV Flight Plan
  • Riegl Sensors
  • Velodyne and Hesai Sensors
  • Helicopter Calibration Flight Plan
  • Additional Considerations
  • Flight Execution
  • Required Data
  1. Data Acquisition and UAV Piloting

Calibration Flight Strategy

PreviousRECON-ANextAcquisition FAQs

Last updated 6 months ago

Determining the X, Y, and Z location of a LiDAR return is strongly dependent on knowledge of the scanner's orientation and location at the time of firing the laser pulse. The scanner's orientation in respect to the center of navigation (usually the IMU) must be known to the thousandth of a degree if range measurements are to be made over long distances. This precise orientation can be solved reliably through the execution of a calibration flight. A proper calibration flight plan should consider the importance of flight location and data coverage in order to facilitate the determination of roll, pitch, and heading misalignments.

Location Selection

The calibration site should contain primarily hard surfaces and be free of vegetation. Flat, pitched structures, such as angled roofs and concrete structures, help the LiDAR optimization routine determine the alignment of the sensor, so it is important to pick a flight location with several buildings or structures. A well defined ground surface per each discrete flight-line will also allow for improvements in sensor alignment.

Requirements

Description

Camera calibration

Easily distinguishable photo-identifiable features (e.g. road paint markings)

LiDAR calibration

Elevated, pitched structures on flat hard ground surface

UAV Flight Plan

to see an example calibration flight plan and trajectory (make sure to enable display of the trajectory under Scene -> Other -> Trajectory). A calibration flight plan should include at minimum two sets of opposing flight-lines. If possible, it is recommended to include four sets of opposing flight-lines, two at a lower AGL and two at a higher AGL. These sets should cross each other perpendicularly over an area that has man-made, pitched structures. Spacing between flight-lines should be 20 meters to ensure sufficient overlap in LiDAR data coverage between flight-lines. Click the download link below to view an example calibration flight with sets of opposing flightlines at 40 and 80 meters AGL.

In general, aircraft speed should be around 6 m/s for calibration missions. Sensor-specific acquisition settings and flight-line AGLs are listed in the tables below.

Riegl Sensors

Sensor

Lines per second

Laser Pulse Rate (KHz)

Lower Flightline AGL (m)

Upper Flightline AGL (m)

miniVUX-1UAV

37.5

100

40

70

miniVUX-2UAV

54

200

40

70

VUX-1UAV

68

550

60

120

VUX-1LR

83

820

60

120

VUX-1HA

113

1000

40

70

Velodyne and Hesai Sensors

When calibrating Velodyne sensors, return mode should be set to dual.

VLP16

1200

30

40

VLP32

1200

40

60 & 80

HDL32

1200

60

80

Pandar XT-32

600

60

80

Pandar XT-32M2X

600

60

80

Helicopter Calibration Flight Plan

A calibration mission plan should include at minimum 2 sets of opposing flight-lines, intersecting each other perpendicularly. After you fly the first flight-line, only make right hand turns, which will result in the cloverleaf pattern shown in Figure 1 and Figure 2 below. Take care to ensure that the helicopter is flying straight and level through the intersection, and straight and level at least 100 meters before and after the intersection point. Flying the same pattern again at a different altitude will improve results.

The flight-line intersection should occur at the center of the street intersection, with the elevated planar features on the four corners of the street intersection, as shown in Figure 3 below.

For the Ranger systems we recommend flying the first cloverleaf at 100 meters AGL and the Second at 140 meters AGL at 820 kHz full power, and not exceeding 30 m/s. Set your camera triggering to allow for at least 75% image overlap for both cloverleaf flying altitudes.

Additional Considerations

Systematic misplacement of points due to sensor misalignment cannot be resolved beyond the accuracy of the trajectory, thus it is important to collect GNSS reference station observations during the calibration flight. Configure your reference station to record raw observations at 1 Hz. Try to include as many frequencies (L1, L2, L5) and constellations (GPS, GLONASS, Galileo, Beidou) in your reference station observations as possible.

Well defined above ground objects can be useful for visual verification of calibration adjustments. If you need to have the IMU and camera calibrated, make sure your camera is focused and set up properly before flight. Changing camera and lens properties after the flight will de-calibrate your camera.

Flight Execution

  1. After powering on the rover (CPU light is green), if IMU is capable of static alignment, leave the system entirely static for 10 minutes. If not, leave it static for 3 minutes.

  2. Take off and gain height until you reach a comfortable altitude.

  3. Fly straight forward at a minimum velocity of 5m/s without changing heading over a distance of 100 meters and fly at least 3 figure-eights. Make sure to always keep the aircraft nose-forward.

  4. Fly the calibration pattern, making sure to include a minimum of two sets of intersecting perpendicular flight lines. Make sure to fly the same pattern again at a different height (about 15 meters higher or lower if using a Scout or about 30 meters with a miniRanger or Ranger) to improve results.

  5. Fly at least 3 figure-eights and then fly straight forward at a minimum velocity of 5m/s without changing heading over a distance of 100 meters. Make sure to always keep the aircraft nose-forward.

  6. Land and perform static alignment routine for 10 minutes if applicable to your IMU. If not, then you can shut down rover 3 minutes after landing.

Required Data

Be sure to upload

  • the reference station observations (RINEX or binary data) covering the ENTIRE flight

  • a photo of the system's setup, how it is mounted to the vehicle and indicating which side of the vehicle faced forward

The calibration flight should include a proper IMU alignment routine. This must be performed BEFORE and AFTER the calibration scan. Follow the steps outlined in the checklist below to ensure the best trajectory and data capture. Refer to for more details on the procedure.

Please upload the calibration data back to Phoenix LiDAR Systems using your account. If you do not have an account yet, please register and contact support@phoenixlidar.com to have your account activated.

the rover dataset (PLP, NAV, LOG, LDR or RXP, and camera data files). You can find this folder by accessing the rover’s \logs directory. Refer to for more information. If your system has an Air NavBox, you can also access Rover data via the removable micro SD card. Refer to for more information.

When you have uploaded the data, send an email to so that we are notified of your upload.

Field Scanning
LiDARMill
Connect to Logs Directory
Rover Data
support@phoenixlidar.com
Follow this link
12KB
VLP80-40_kmz.kmz
Example Flightplan KMZ
Recommended sets of intersecting perpendicular flight lines
Recommended sets of intersecting perpendicular flight lines
Cloverleaf calibration pattern
Cloverleaf boresight pattern (note straight intersecting lines)
Street intersection with photo-identifiable paint markings and elevated planar features on street corners