PSD Focal Plane Array for Optical Tracking
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Solution Overview
Problem
Existing optical tracking systems for military and commercial applications face limitations in speed, accuracy, and detection capability, particularly in passive tracking scenarios without active illumination, necessitating advancements in object detection and location methods.
Innovation Solution
A Position Sensing Detector (PSD) based Focal Plane Array (FPA) is developed, constructed as a semiconductor chip sandwich with IR-sensitive PSDs and Trans Impedance Amplifiers, enabling uniform element spacing, integrated electronics, and background mitigation techniques to enhance detection and location accuracy in infrared optical tracking systems.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If traditional pixel arrays are used in optical tracking systems, then the system can achieve basic detection capability, but the speed and accuracy of tracking are limited
Solution Approach 1:
The invention divides the detection function into two distinct components: PSD elements for high-speed position detection and pixel arrays for imaging. This segmentation allows each component to be optimized for its specific function, with PSDs providing fast position metrics and pixels providing visual confirmation, thereby resolving the contradiction between tracking speed and accuracy.
Solution Approach 2:
The invention merges PSD technology with focal plane array architecture to create a hybrid detector that combines the high-speed position sensing capabilities of PSDs with the imaging capabilities of pixel arrays. This merging enables simultaneous high-speed tracking and accurate position measurement without the limitations of traditional single-type systems.
2Object-affected harmful factors
If passive tracking without active illumination is used, then the system can operate covertly, but background mitigation becomes significantly more difficult
Solution Approach 1:
The invention applies local quality by using PSD elements that are highly sensitive to localized position changes of targets against the background. Each PSD element provides precise position metrics for its specific region, enabling reliable detection even in passive mode by focusing on local position changes rather than requiring global background subtraction.
3Manufacturing precision
If uniform element-to-element characteristics are required in PSD arrays, then manufacturing precision must be extremely high, but this increases manufacturing difficulty and cost
Solution Approach 1:
The invention incorporates feedback mechanisms where each PSD element's position metrics are processed and used to adjust subsequent detection and tracking operations. This feedback approach allows the system to compensate for minor manufacturing variations in PSD elements, maintaining high tracking accuracy without requiring extremely tight manufacturing tolerances for each individual element.
4Area of stationary object
If close spacing between PSD elements is implemented, then the field-of-view and resolution are improved, but the complexity of integrated electronics circuits increases
Solution Approach 1:
The invention transitions from planar integration to three-dimensional stacking, with PSD elements on one substrate and readout electronics on another substrate. This dimensional change allows close spacing of PSD elements for high resolution and wide field-of-view while managing electronics complexity through vertical integration rather than planar scaling.
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
The PSD FPA system achieves high accuracy and multiple target processing with improved sensitivity and functionality, extending the operational limits of existing systems to new regimes, providing accurate positional metrics and wide field-of-view capabilities in fast-tracking platforms.
Implementation Method 1
Position Sensing Detector (PSD) based Focal Plane Array (FPA) extends the limits of existing systems to new operational regimes
Data Source
AI summary
A Sensor Chip Assembly (SCA) contains a focal plane array constructed as a semiconductor chip sandwich. One slice contains an array of PSDs made from IR sensitive semiconductor material, and the other slice contains Trans Impedance Amplifiers (TIAs)—and associated on-chip signal processing elements from an electronic semiconductor material. The SCA resembles those made for pixelized imaging IR SCA focal planes, but the configuration and implementation of which is for a PSD focal plane array. The use of these techniques assures that the PSD focal plane array possesses the required attributes. Interconnect technology is widely available from most IR fabrication houses to connect the IR array with the TIA circuits.