LiDAR with Reduced-Length Linear Detector Array
Optics
LiDAR with Reduced-Length Linear Detector Array (GSC-TOPS-382)
Multi-Track Swath-Mapping 3D Imaging Using a Compact Lidar System
Overview
In recent years, LiDAR innovations have significantly improved instrument sensitivity and efficiency while reducing size, weight, and power requirements. Future Earth and planetary science missions require more compact and efficient ranging LiDARs capable of probing multiple profiles and enabling 3D imaging. However, a key limitation is the size of available 1D detector arrays within LiDAR systems, which constrains the footprint swath.
To address this challenge, engineers at NASA Goddard Space Flight Center developed the LiDAR with Reduced-Length Linear Detector Array, an advancement in next-generation LiDAR technology that enables multi-track swath mapping with 3D imaging. This invention introduces new methods to minimize the required 1D detector array size, reduce speckle noise, and lower unwanted solar photon counts—without the need for additional gratings. By substantially decreasing form factor and power requirements while enhancing performance, this innovation provides users with greater operational flexibility and expanded capabilities while reducing costs.
The Technology
The LiDAR with Reduced-Length Linear Detector Array improves upon a prior fast-wavelength-steering, time-division-multiplexing 3D imaging system with two key advancements: laser linewidth broadening to reduce speckle noise and improve the signal-to-noise ratio, and the integration of a slow-scanning mirror with wavelength-steering technology to enable 2D swath mapping capabilities. Range and velocity are measured using the time-of-flight of short laser pulses. This highly efficient LiDAR incorporates emerging technologies, including a photonic integrated circuit seed laser, a high peak-power fiber amplifier, and a linear-mode photon-sensitive detector array.
With no moving parts, the transmitter rapidly steers a single high-power laser beam across up to 2,000 resolvable footprints. Fast beam steering is achieved through an innovative high-speed wavelength-tuning technology and a single grating design that enables wavelength-to-angle dispersion while rejecting solar background for all transmitted wavelengths. To optimize receiver power and reduce data volume, sequential returns from up to 10 different tracks are time-division-multiplexed and digitized by a high-speed digitizer for surface ranging. Each track’s atmospheric return can be digitized in parallel at a lower resolution using an ultra-low-power digitizer.
Originally developed by NASA for SmallSat missions, this system’s precise and accurate observation capabilities—combined with reduced costs, size, weight, and power constraints—make it applicable to a wide range of LiDAR applications. The LiDAR with Reduced-Length Linear Detector Array is currently at Technology Readiness Level (TRL) 4 (validated in a laboratory environment) and is available for patent licensing.
Benefits
- Compact and Energy-Efficient: Utilizes a smaller detector array and advanced digitization to reduce size, weight, and power demands.
- Precise Imaging: Laser linewidth broadening reduces speckle noise and improves signal-to-noise ratio.
- Broad Spectral Filtering: Single grating design effectively rejects solar background across all transmitted wavelengths.
- Efficient Data Processing: Time-division multiplexing reduces receiver power needs and data volume while maintaining accuracy.
- High-Resolution Swath-Mapping: Combines wavelength-steering and a slow-scanning mirror to enable 2D swath mapping capabilities
Applications
- Orbital Navigation: Reduced speckle noise and unwanted solar photons count allow smaller laser footprints needed for precise maneuvers.
- Weather Monitoring: Assesses more and larger scale weather patterns than Doppler systems in less time.
- Earth and Planetary Science Missions: Enables precise topographic mapping and surface characterization for research and exploration.
- Coastal and Bathymetric Mapping: Measures water depth and underwater topography for environmental monitoring and resource management.
- Atmospheric Research: Enables profiling of aerosols, clouds, and atmospheric composition for weather and climate research.
- Autonomous Vehicles: Compact and energy-efficient systems for navigation and obstacle detection.
Technology Details
Optics
GSC-TOPS-382
GSC-18800-1
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