When to Use Aerial Bathymetric LiDAR—Advantages and Limitations

Mapping underwater environments with precision has always been a challenge for scientists, engineers, and environmental planners. Aerial Bathymetric LiDAR (Light Detection and Ranging) has emerged as an innovative solution, offering the ability to collect highly accurate, non-invasive depth data from the air. But like any technology, it has its strengths, limitations, and optimal use cases.

 

What is Aerial Bathymetric LiDAR?

Aerial Bathymetric LiDAR is a modern remote sensing technology that uses green wavelength lasers (around 532 nm) to penetrate the water surface and measure depths. Unlike traditional sonar methods—which rely on sound waves and are conducted point by point from a vessel—LiDAR operates from an aircraft, scanning wide areas in a single pass. This allows it to capture both the seabed and surrounding terrain with speed and consistency, making it especially effective for mapping shallow coastal zones, reefs, and other sensitive environments.

In short: LiDAR uses light, sonar uses sound. LiDAR offers rapid, large-scale coverage from the air, while sonar remains the conventional approach for detailed, vessel-based surveys.

Unlike traditional ship-based sonar, which collects data point-by-point from the water, aerial bathymetric LiDAR surveys large swaths from above, integrating topographic LiDAR for land mapping with underwater terrain data to create seamless land–sea digital elevation models (Kujawa & Remondino, 2025).

Feature	Aerial Bathymetric LiDAR (Light)	Traditional Sonar (Sound)
Technology	Uses green laser light (~532 nm) to penetrate water and measure depth	Uses sound waves (acoustic pulses) sent from a vessel to measure depth
Platform	Aircraft-mounted (plane)	Vessel-based
Coverage	Scans wide areas in a single flight—tens of km² per mission	Point-by-point coverage; requires multiple passes for wide areas
Speed	Very fast—large coastal areas can be mapped in hours or days	Slower—large areas may take months of vessel operations
Resolution	High-resolution mapping (decimeter level in clear waters); captures seabed + terrain	Point-by-point type of data similar to surveying conventional method.
Environmental Impact	Non-invasive; no noise pollution or seabed disturbance	May cause noise disturbance; vessels may disturb sensitive habitats
Best Use Cases	Shallow, clear waters, reefs, coastal zone management, disaster response	Small-scale and projects that does not require detailed mapping only points.
Limitations	Limited by water clarity (turbid/murky waters reduce accuracy)	Labor intensive.

Advantages of Aerial Bathymetric LiDAR

Sample Output of ABSD (Aerial Bathymetric LiDAR)

1) Non-invasive mapping for sensitive ecosystems

What it means:Instead of sending a boat with sonar into the water, a plane or helicopter flies overhead and sends a safe green laser into the water to measure depth. There’s no propeller wash, no anchor drops, and far less noise in the water.

Why it matters: Coral reefs and seagrass beds are fragile. Boats can stir up sediment, break corals, or scare marine life. Aerial LiDAR gets the data without touching the habitat, which is ideal for marine protected areas.

Applications:

• Coral reefs, seagrass meadows, shallow lagoons

• Marine Protected Areas (MPAs) and research zones

• Sites with lots of rocks/reefs where boats would struggle

Real-world example: In Talim Bay, Batangas, bathymetric LiDAR mapped coral, seagrass, rock, and sand at sub-meter detail without disturbing the site (Arenas & Botor, 2025).

 

ABSD's Aerial Bathymetric LiDAR (Batangas)

2) Speed and coverage

What it means: From the air, LiDAR scans wide swaths in one pass. Large coastlines or shallow zones that would take weeks by boatcan be covered in days.

Why it matters:

• Tighter timelines: You get decision-ready maps faster.

• Fewer weather delays: Shorter field time reduces risk from bad sea states.

• Rapid response: Ideal after storms or typhoons when conditions change quickly.

Applications:

• Long coastlines, reef systems, island chains

• Post-disaster assessments (erosion, sediment movement)

• Baseline surveys that must be repeated regularly

Real-world example: After Caribbean hurricanes, rapid LiDAR flights helped locate sediment shifts and coastal damage within days, guiding recovery work.

 

Aerial Bathymetric 3D Digital Terrain Model (Multi-layered Data)

3) High-resolution, multi-layered data

What it means: Beyond a plain depth map, LiDAR lets us compute extra layers (often called “derivatives”) that describe the seafloor’s shape and texture:

• Slope: How steep the bottom is.

• Curvature: How the surface bends (helps spot features like ridges).

• Roughness/Rugosity: How bumpy or complex the bottom is (useful for habitat quality).

Why it matters: These layers help classify habitats (e.g., coral vs. sand) and support engineering (foundation siting, scour risk, sediment pathways).

Applications:

• Habitat mapping and marine zoning

• Coastal engineering and dredging design

• Erosion and shoreline change studies

Real-world example: For renewable energy planning, LiDAR depth + sub-bottom profilers (to see sediment layers) gave engineers the surface and subsurface picture needed to design wind turbine foundations that avoid sensitive habitats and sit on stable ground.

 

Classification - Different colors representing coral, seagrass, rocks, and sand -- AI assisted Data. (Source: Arenas & Botor, 2025)

4) Integration with AI and machine learning

What it means: AI models (like Random Forest and Support Vector Machine) can be trained to auto-label seabed features (coral, rock, sand) from LiDAR-derived layers. Think of it as a smart assistant that speeds up sorting and mapping.

Why it matters:

• Faster processing: Less manual drawing and checking.

• Consistency: The same rules are applied across big areas.

• Scalability: Large regions can be mapped under tight timelines.

What it still needs: Good training data (ground truth) and a quick human quality check to correct any mislabels.

Real-world example: ABSD’s benthic mapping used AI-assisted workflows to cut manual time by over 50%, while reaching ~93.4% classification accuracy in tests (Arenas & Botor, 2025).

 

• Gentle on reefs: Aerial LiDAR protects sensitive habitats by staying out of the water.

• Fast for big areas: Days instead of weeks for long coastlines or multiple islands.

• Richer insights: Depth + shape/texture layers = better habitat maps and engineering inputs.

• Even faster with AI: Automated classification makes delivery quicker and more consistent.

 

Limitations of Aerial Bathymetric LiDAR

1. Water Clarity Dependency

The green laser’s penetration depends heavily on water clarity. In turbid, sediment-rich, or algae-bloom-affected waters, data quality drops significantly.

Example: Surveys in Manila Bay during the rainy season faced reduced penetration depths due to suspended sediments from river inflows.

 

2. Shallow Water Optimization

Bathymetric LiDAR is most effective in shallow coastal zones (typically <50 m depth in clear waters). For deeper waters, multibeam sonar remains more reliable.

 

 

When to Use Aerial Bathymetric LiDAR

Best for:

✅ Coral reef monitoring without physical disturbance.

✅ Coastal engineering where both land and seabed mapping are needed.

✅ Disaster response for rapid large-area mapping.

✅ Marine biodiversity monitoring for habitat classification and change detection.

✅ Renewable energy site planning (offshore wind, tidal energy).

Not ideal for:

❌Highly turbid or polluted waters.

❌Very deep-water mapping (>50 m).

❌Low-budget projects requiring only approximate depth data.

 

Note: The maximum laser penetration is 30 meters, depending on water clarity. This is typically estimated as 2.5 times the Secchi disk depth, which varies based on water turbidity and clarity.

 

Aerial Bathymetric LiDAR is redefining the standards of marine and coastal surveying. Its ability to deliver rapid, high-resolution, and environmentally sensitive data collection means decision-makers no longer have to choose between speed, precision, and sustainability. By scanning vast coastal zones from the air without physical contact, it eliminates many of the risks posed by traditional boat-based surveys—especially in fragile ecosystems like coral reefs, mangroves, and seagrass meadows.

However, like all advanced tools, its true value is unlocked when applied to the right conditions. Clear, shallow waters allow its green laser (532 nm) to penetrate effectively, while large-scale coverage needs—such as post-disaster assessments, renewable energy site planning, or biodiversity monitoring—make full use of its speed and spatial efficiency. In these scenarios, the return on investment isn’t just measured in data quality, but also in the time saved and the ecological impact avoided.

 

At AB Surveying and Development (ABSD), we understand that no single method fits every project. That’s why our approach often goes beyond standalone bathymetric LiDAR. We customize hybrid solutions that may combine aerial bathymetry with topographic LiDAR (for land–sea seamless mapping), multibeam sonar (for deep-water detail), sound velocity profiling (for depth accuracy), marine magnetometry (for detecting submerged infrastructure), and AI-powered classification workflows. This integrated approach ensures that the datasets we deliver are not only precise, but also structured and enriched for direct use in critical decision-making—whether that’s designing resilient coastal infrastructure, planning offshore energy facilities, or managing marine conservation zones.

 

The projects that succeed are the ones that are both technically sound and ecologically responsible. By aligning the strengths of Aerial Bathymetric LiDAR with the specific needs of each project, ABSD ensures that our clients receive data that drives progress while safeguarding the marine environments we all depend on. "That is what we mean by going Above and Beyond."

Get in touch with us at info@absurveyingph.net or

visit www.absurveyingph.net to connect with #TheLidarGuys and explore tailored geospatial solutions that go above and beyond.

#ABSD #AboveAndBeyond #LiDARMapping #OffshoreWind #RenewablesPH

References:

Arenas, I. R. A., & Botor, J. B. B. (2025). Development and comparative assessment of methodologies for benthic feature classification using bathymetric LiDAR and machine learning [Undergraduate thesis, University of the Philippines Diliman].Kujawa, P., &

Remondino, F. (2025). A review of image- and LiDAR-based mapping of shallow water scenarios. Remote Sensing, 17(12), 2086. https://doi.org/10.3390/rs17122086