LiDAR data

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Data Format and Structure

• Data must be provided in a LAS or LAZ format - compressed LAZ files are preferred for file size management reasons.
• Point cloud density requirements should be >8 points per m² to ensure sufficient detail for individual tree detection and crown delineation.
• The Point Data Record Format should be 6 or higher to include RGB and NIR values, as well as additional metadata.
  • Fields included should be:
    • X, Y, Z coordinates
    • Intensity
    • Return Number
    • Number of Returns
    • Classification
    • RGB values
    • GPS Time
    • Scan Angle

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Data Requirements

• Tiling scheme should be 1km x 1km tiles with a 50m overlap.
• File name should be in format: ProjectID_AAAABBBB_YYYYMMDD where AAAA is the Easting grid reference and BBBB is the Northing grid reference.
• UTM coordinate system should be used.
• NAVD88 or local equivalent should be used as a vertical datum.
• All measurements must be in metres.
• Classification accuracy
  • Ground points: 95% correctly classified
  • Vegetation (by height class): 90% correctly classified
  • Buildings: 95% correctly classified
  • Water bodies: 95% correctly classified
  • Minimum classification categories required:
    • Ground
    • Low Vegetation (0-0.3m)
    • Medium Vegetation (0.3-2m)
    • High Vegetation (>2m)
    • Buildings
    • Low Points/Noise
    • Water
    • Bridge Decks
    • High Noise
• Absolute vertical accuracy should be ≤ 15cm RMSE at the 95% confidence level.
• Pulse density should be at least 4 pulses per m².

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File Metadata

• Metadata should be ISO 19115 compliant and include:
  • Unique persistent identifier for the dataset
  • Collection Date/Time (GPS Time)
  • Scanner specifications:
    • Manufacturer, Model and Serial Number
    • Calibration parameters and dates
  • Flight parameters:
    • Height
    • Speed
    • Pulse rate
    • Scan rate
    • Flight line overlap percentage
  • Processing details:
    • Software used (including version)
    • Classification scheme and accuracy metrics
    • Strip adjustment parameters and results
    • Ground control point information
  • Quality control data:
    • Point density maps
    • Coverage verification
    • Accuracy assessment results
    • Classification accuracy metrics
  • Data derivatives information (if applicable)
    • Source data references and lineage
    • Access and usage restrictions
    • Keywords following standardized vocabularies
    • Point of contact information
• Metadata should be provided in both human and machine-readable formats.
• Quality reports must include reproducible methodology.