Masked Photon-Counting Pixel Array for Real-Time LiDAR Noise Separation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Geiger-mode LiDAR systems face challenges in accurately characterizing intrinsic noise sources, particularly in high-density pixel arrays, which affects signal-to-noise ratio and spatial resolution, especially in dynamic environments.
Innovation Solution
A single photon counting sensor array with a mask material covering some detectors to differentiate between blocked and unblocked pixels, allowing for real-time characterization of intrinsic noise by comparing signal characteristics between masked and unmasked pixels, and using a processor to determine noise measurements and compensate for crosstalk.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If Geiger-mode photodiode detectors are used to increase sensitivity for single photon counting, then light detection sensitivity is improved, but intrinsic noise components from surrounding environment and system increase
Solution Approach 1:
The detector array is segmented into multiple pixels, with at least one pixel blocked by mask material to create a blocked pixel that detects only intrinsic noise. This segmentation allows separate measurement of signal-containing pixels and noise-only pixels, enabling noise subtraction to improve overall measurement precision while maintaining high sensitivity.
Solution Approach 2:
The intrinsic noise component is extracted from the total signal by using blocked pixels that detect only noise without signal. The noise measurement from blocked pixels is then subtracted from unblocked pixel measurements, separating the harmful noise component from the useful signal to improve signal-to-noise ratio.
2Measurement precision
If high density array of tightly pitched pixels is deployed for better spatial resolution, then spatial resolution is improved, but crosstalk interference between neighboring pixels increases
Solution Approach 1:
The detector array is divided into many tightly pitched pixels with at least one blocked pixel included in the array. This segmentation enables measurement of crosstalk noise from blocked pixels, which can then be subtracted from neighboring unblocked pixels to reduce crosstalk interference while maintaining high spatial resolution.
Solution Approach 2:
Crosstalk interference is extracted and measured using blocked pixels that are surrounded by unblocked pixels in the high-density array. The crosstalk signal detected in blocked pixels is subtracted from adjacent unblocked pixels, removing the harmful crosstalk component while preserving the beneficial high spatial resolution.
3Measurement precision
If blocked pixels are introduced to characterize intrinsic noise, then noise characterization accuracy is improved, but device complexity increases due to mask material and additional processing
Solution Approach 1:
Blocked pixels serve multiple functions: they characterize intrinsic noise, measure crosstalk interference, and provide reference data for noise subtraction. This multi-functionality justifies the added complexity of mask material and processing, as the same blocked pixels contribute to improving noise characterization accuracy and overall system performance.
Solution Approach 2:
Blocked pixels act as copies of the detector structure that are identical in construction but differ in function by being masked. These copied pixel structures allow measurement of noise and crosstalk without affecting the signal detection capability of unblocked pixels, enabling noise characterization while maintaining system simplicity.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach enhances the signal-to-noise ratio and allows for improved spatial resolution and noise suppression in LiDAR systems, enabling better performance in dynamic environments by accurately distinguishing between signal and noise components.
Implementation Method 1
A mask material is positioned to cover some but not all of the detectors of the plurality of pixels to yield blocked pixels and unblocked pixels so that each blocked pixel is prevented from detecting the reflected pulses of energy
Implementation Method 2
improvements in LiDAR systems that utilize avalanche photodiodes in Geiger-mode (GmAPD) allow for single photon counting and can provide increased sensitivity for light detection
Implementation Method 3
One method of determining the location of such objects is by time-of-flight (TOF) where light pulses are emitted from the sensor and the distance to the target is determined by the round trip time of the reflected pulse, since the speed of light is constant
Data Source
AI summary
A single photon counting sensor array includes one or more emitters configured to emit a plurality of pulses of energy, and a detector array comprising a plurality of pixels. Each pixel includes one or more detectors, a plurality of which are configured to receive reflected pulses of energy that were emitted by the one or more emitters. A mask material is positioned to cover some but not all of the detectors of the plurality of pixels to yield blocked pixels and unblocked pixels so that each blocked pixel is prevented from detecting the reflected pulses of energy and therefore only detects intrinsic noise.