Long Island Sound Topobathymetric Lidar 2023

2023 NOAA NGS Lidar data for Long Island Sound, NY, collected in four blocks across 69 missions flown between March and October 2023. The dataset includes topobathymetric point clouds in LAS 1.4 format with 18 distinct classification codes and 4 channel bits for sensor identification. Data features lidar intensity values, number of returns, return number, time, and scan angle, compiled into 500 m x 500 m tiles.

Use Cases

• Analyze bathymetric bottom (classification 40) and water column (45) point densities to model seafloor topography and submerged features.
• Segment point clouds by classification codes like Submerged Aquatic Vegetation (64) and Ground (2) for coastal habitat mapping.
• Differentiate sensor data using channel bits (0-3) and user byte values (10-30) to assess performance of Chiroptera and Hawkeye laser systems.
• Normalize green laser intensity values for depth to correct for water column attenuation in bathymetric analysis.
• Identify temporal differences in bathymetry using overlap classifications (65, 71, 72) from separate data collection lifts.

Strengths

• Data collection spanned 69 distinct missions across four blocks, providing dense spatial and temporal coverage.
• Includes 18 specific ASPRS classification codes enabling detailed feature extraction for both topographic and bathymetric analysis.
• LAS files were reviewed and corrected based on NOAA feedback, and intensity values were normalized for depth in two blocks.
• Point data includes multiple attributes: intensity, number of returns, return number, time, and scan angle.

Limitations

• The total number of data points (rows) and file size are not specified, making workload estimation difficult.
• Primary file formats listed are PDF and HTML, suggesting metadata documentation rather than direct access to the raw LAS point cloud data.
• Data is limited to the Long Island Sound region of New York and Connecticut, not applicable for broader geographic studies.

Provenance

Source

National Oceanic and Atmospheric Administration (NOAA), National Geodetic Survey (NGS).

Collection Method

Collected via airborne survey using NV5's Leica Chiroptera/Hawkeye 4X and Chiroptera/Hawkeye 5 lidar systems.

Time Range

March 5, 2023 to October 28, 2023.

Freshness

Data was collected in 2023 and the metadata was last updated in March 2026.

Geography

Long Island Sound, covering areas of New York and Connecticut, USA.