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
  1. General FAQ
  2. Accuracy Standards & Quantification

Further Considerations

PreviousAbsolute AccuracyNextMapping Terms and Definitions

Within the ASPRS guidelines and USGS specifications there is significant room for ambiguity in the end result caused by the user’s ability to select which points are considered when building a TIN for swath-to-swath and absolute accuracy computation. This ambiguity ultimately stems from the precision of data that a scanner is producing and the ground classification routine chosen. Current LiDAR systems available on the market, especially when mounted to slow and low flying UAS, produce extremely dense data, where the scanner’s precision is a very noticeable quality factor. A variety of methods for classifying ground and producing a final DEM exist, all possibly impacted by precision.

In short, a fuzzy layer of hard surface points leaves room for the implemented workflow to have a dramatic influence on accuracy metrics. We will illustrate 3 scenarios for an imprecise scanner that can greatly impact the absolute accuracy resulting statistics:

  • All Points Surface: Datasets lacking high precision will have a somewhat “fuzzy” layer of points on hard surface targets. If the entire layer of fuzz is considered to be “ground” by the user then the over and under estimation of absolute accuracy will be unpredictable. In this example, the “All Points Surface” will overestimate the accuracy of checkpoint A, and underestimate the accuracy of checkpoint B. User’s may choose to use this way of looking at their data in order to remain independent of classification algorithm or parameter selection.

  • Mean Surface: Creating a mean or other statistically interpolated surface that fits near the center of a dataset’s fuzz can reduce the randomness of using an all points TIN. It can also better represent the true surface by minimizing the impact of imprecision. This method is particularly useful for quantifying accuracy when the user is making products, DEM, Contours, Etc., from the interpolated surface. If this method is chosen then it is advisable to also convey a dataset’s precision to the end user as it may give a misleading impression if the full point cloud is later used to measure features that are impacted by imprecision. This is similar to the method outlined by M. Isenburg at the LiDAR for Drone 2017 Conference: https://rapidlasso.com/2017/10/29/processing-drone-lidar-from-yellowscans-surveyor-a-velodyne-puck-based-system/

  • Generic Ground Classified Surface: Many ground classification routines tend to work very well with lower density airborne lidar data. With point densities in the 2-8 points/m² range on the ground, common ground classifiers are sufficient for surface modeling. However, on very dense datasets the lowest elevation points tend to get selected. These points also often happen to be outliers. Comparing surveyed checkpoints to elevation values from a TIN of generic ground classification results has the potential to produce undesirable results.

An example of various ways to define a ground surface from LiDAR points