Discover how MEMS-based LiDAR enables non-invasive monitoring of undersea marine life with unprecedented clarity and precision
Beneath the ocean's surface lies a world of breathtaking complexity, one that sustains vital ecosystems and regulates our planet's climate. For scientists and environmental managers, observing marine life without disruption has long been a formidable challenge.
Traditional monitoring methods—whether intrusive cameras with their blinding lights or limited acoustic systems—have struggled to provide the detailed, non-invasive data needed to understand marine environments truly. How can we study delicate underwater ecosystems without disturbing the very creatures we seek to protect?
Enter an innovative technology once reserved for space exploration and self-driving cars: MEMS-based serial LiDAR. This advanced imaging system represents a breakthrough in non-invasive marine monitoring, offering a window into underwater worlds with unprecedented clarity and precision.
By harnessing micro-scale mirrors and laser pulses, this technology is revolutionizing our approach to undersea surveillance, enabling researchers to observe marine life naturally and unobtrusively for the first time.
Invisible laser light doesn't disturb marine life
Centimeter-level resolution for detailed imaging
Works in various water conditions and turbidity levels
LiDAR, which stands for Light Detection and Ranging, operates on a simple but powerful principle: it measures distance by calculating the time it takes for laser pulses to travel to an object and back. Each laser pulse acts as a microscopic ruler, building precise three-dimensional maps point by point. While LiDAR has been used for decades in fields ranging from meteorology to archaeology, its application to marine environments has historically faced significant limitations 3 .
Traditional underwater monitoring has relied primarily on two technologies:
MEMS LiDAR bridges this gap by offering both precision and non-invasiveness, creating what developers call an "unobtrusive" monitoring solution 6 .
The transformative element in this technology is the Micro-Electro-Mechanical Systems (MEMS) mirror—a tiny, movable mirror that directs laser beams with incredible precision. These microscopic mirrors, typically measuring just 1-7 millimeters in diameter, steer laser pulses without the bulky mechanical parts that characterized earlier LiDAR systems 3 .
In marine applications, MEMS LiDAR systems use red laser illumination (638 nanometers) specifically configured to be invisible and eye-safe for marine animals 6 . This careful wavelength selection is crucial—it places the laser beyond the visual sensitivity range of most marine creatures while ensuring safety for both animals and humans 6 .
1-7mm diameter
Precision beam steering
What sets advanced MEMS LiDAR systems apart is their intelligent, two-tiered scanning approach:
A sparse, wide-area scan that efficiently covers large volumes of water to detect potential objects of interest.
Efficient scanning of large areas
Once detected, the system automatically switches to a dense, high-resolution scan of a narrower area to obtain identification-quality imagery 6 .
Detailed imaging for identification
This dynamic approach allows the system to cover large areas efficiently while still capturing the detailed imagery needed for scientific analysis—all in near real-time.
In October 2017, researchers conducted a critical field test of the Unobtrusive Multi-static Serial LiDAR Imager (UMSLI) in the turbid coastal waters of Sequim Bay, Washington 6 . This location offered challenging conditions typical of many coastal environments—exactly the scenario where traditional monitoring methods struggle most.
The research team faced a significant obstacle: the lack of natural marine species encounters during the testing period. To overcome this, they employed divers to position artificial marine life targets within the UMSLI's field of view, including models of turtles and barracuda for which the system's classification algorithms had been previously trained 6 .
October 2017
Sequim Bay, WA
Turbid Coastal Waters
Artificial Marine Life
The UMSLI experiment followed a meticulous process:
Researchers mounted the UMSLI system on a deployment frame that was either lowered into the water column or placed directly on the ocean bottom, with a single power and Ethernet cable connecting it to surface monitoring equipment 6 .
The system was operated in a profiling mode with six distinct channels, each capable of independent scanning and data collection 6 .
Specialized algorithms processed the returning signals to reconstruct the illuminated volume and output imagery of areas of interest, using bilateral pulse shaping methods to enhance image quality 6 .
This systematic approach allowed researchers to test both the detection and identification capabilities of the system under realistic field conditions.
The field testing yielded valuable quantitative data about the system's performance under various environmental conditions. The results demonstrated both the capabilities and limitations of this emerging technology.
| Water Conditions | Beam Attenuation Coefficient | Maximum Imaging Range |
|---|---|---|
| Daylight Operations | 0.75-1.2 m⁻¹ | 3 beam attenuation lengths |
| Nighttime Operations | 0.75-1.2 m⁻¹ | 5 beam attenuation lengths |
The data revealed a clear performance difference between daylight and nighttime operations, with the system achieving approximately 67% greater range after dusk when ambient light was minimal 6 . This performance variation underscores one of the remaining challenges for the technology—managing environmental interference.
| Parameter | Specification |
|---|---|
| Laser Wavelength | 638 nm (red) |
| Scan Cycle Time | 400 ms |
| Imaging Capability | Range-sliced identification |
| Channels | 6 independent transceivers |
Perhaps most impressively, the system demonstrated a remarkable ability to transition from detection to identification mode within a single 400-millisecond scan cycle 6 . This rapid response is critical for capturing useful data on moving marine animals that might otherwise leave the field of view before detailed imaging occurs.
When compared to traditional monitoring approaches, MEMS LiDAR demonstrates distinct advantages:
| Technology | Optimal Range | Resolution | Marine Life Disruption | Primary Limitations |
|---|---|---|---|---|
| MEMS LiDAR | 10-20 meters (depends on turbidity) 2 | Centimeters to meters 2 | Minimal (invisible laser) 6 | Limited by water clarity and ambient light 6 |
| Optical Cameras | < 7-8 meters 2 | < 1 centimeter 2 | High (often requires bright lights) 6 | Limited range, requires clear water and light |
| Acoustic Systems | Tens of meters 2 | 20 cm to >1 meter 2 | Varies (potential behavioral effects) | Lower resolution, intuitive interpretation difficult |
| Marine Sonar | Hundreds of meters 8 | Limited shape detail | Unknown (pressure waves) | Cannot transmit through air-water interface 8 |
Developing an effective MEMS LiDAR system for underwater surveillance requires specialized components, each playing a critical role in the imaging process:
The heart of the system, this tiny mirror steers laser pulses in precise patterns across the surveillance area without mechanical movement 6 .
These provide the illumination source, with red (638 nm) wavelengths specifically chosen to be invisible and eye-safe for marine life 6 .
Extremely sensitive detectors that capture the returning laser pulses with nanosecond precision 6 .
Optical filters that isolate the specific laser wavelength while excluding ambient light that could interfere with detection 6 .
Specialized computing hardware that reconstructs the illuminated volume from the returning signals and generates imagery 6 .
Machine learning software trained to recognize specific marine species from the LiDAR data, enabling automated detection and monitoring 6 .
The development of MEMS LiDAR for underwater monitoring comes at a critical time for ocean conservation. As human activities increasingly impact marine ecosystems, the need for effective, non-disruptive monitoring technologies has never been greater.
This technology promises transformative applications across multiple domains:
Monitoring interactions between marine animals and tidal or wave energy converters without altering natural behaviors 6 .
Conducting population surveys and studying fish behavior without the disruption caused by traditional methods.
Enabling continuous monitoring of sensitive ecosystems without the disruptive presence of human observers.
Providing new insights into animal behavior, species distribution, and ecosystem dynamics through extended-duration, non-invasive observation.
While the current UMSLI prototype demonstrated promising capabilities, researchers note that the system is "still quite large" but has "potential to be very compact, low power consumption, and cost-effective once fully developed" 6 . Ongoing developments in MEMS technology are rapidly addressing these limitations, with newer systems achieving remarkable specifications:
Recent MEMS LiDAR advances have demonstrated angular resolution of 0.07° × 0.027° (horizontal × vertical)—over 13 times better than earlier commercial systems—while maintaining a reasonable cost profile of approximately $1,700 for some research systems 9 .
This continuous improvement in performance and reduction in cost promises to make the technology increasingly accessible for marine research and conservation applications.
Future iterations may incorporate multi-static configurations with separate transmitter and receiver units, potentially improving performance in turbid waters where scattered light typically degrades image quality 6 . Additionally, the integration of artificial intelligence for real-time species identification and behavioral analysis represents an exciting frontier that could dramatically reduce the data processing burden on researchers.
More compact and affordable systems
Real-time species identification
Improved performance in turbid waters
Extended deployment capabilities
MEMS-based serial LiDAR imaging represents more than just a technological achievement—it offers us a new relationship with the ocean world. For the first time, we can observe marine life in its natural state, going beyond mere documentation to genuine understanding. As this technology continues to evolve, it promises to illuminate the hidden mysteries of the deep while helping ensure that our quest for knowledge doesn't come at the expense of the creatures we seek to study.
In the delicate balance between scientific progress and environmental preservation, MEMS LiDAR offers a rare win-win: advancing human knowledge while respecting marine ecosystems. As we stand at this technological frontier, we're not just developing better monitoring systems—we're learning how to see without interfering, how to study without disrupting, and how to satisfy our curiosity about the natural world while honoring our responsibility to protect it.