Uncooled Thermal Imaging Signature Mitigation via Non-Uniform Timing
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Solution Overview
Problem
Conventional imaging systems using microbolometers can be detected by other imaging systems due to uniform timing in pulse biasing, which creates a detectable signature.
Innovation Solution
Implementing a non-uniform timing sequence between frames and lines in the imaging system, using a processor to generate frame and line synchronization signals based on a main clock, with delay values and bounded pseudo-random values to spread the signature over frequency, making detection more difficult.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Difficulty of detecting and measuring
If uniform timing is used in pulse biasing, then system operation is simple and reliable, but the imaging system becomes detectable by other imaging systems
Solution Approach 1:
The patent applies dynamics by transitioning from uniform timing to non-uniform timing in pulse biasing. The timing between frames and lines is varied dynamically using pseudo-random number generators and delay tables, making the timing pattern unpredictable and thus undetectable by other imaging systems while maintaining operational reliability
Solution Approach 2:
The patent changes the timing parameter from uniform to non-uniform intervals. By modifying the time intervals between frame synchronization signals and line synchronization signals using pseudo-random values and delay tables, the system creates a variable timing pattern that spreads the thermal signature over frequency, reducing detectability
2Difficulty of detecting and measuring
If non-uniform timing is implemented, then detection likelihood is reduced, but system complexity increases
Solution Approach 1:
The system uses self-service by incorporating pseudo-random number generators and delay tables that are built into the imaging system itself. These components automatically generate the non-uniform timing patterns without requiring external control, making the system self-sufficient in creating its own detection-resistant timing signature
Solution Approach 2:
The patent implements periodic action through frame synchronization signals and line synchronization signals that are generated at regular intervals but with varying delays. The periodic nature is maintained for system operation while the variable delays create non-uniform timing that reduces detectability
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 non-uniform timing reduces the likelihood of detection by another imaging system, spreading the signature over frequency and increasing bandwidth, thereby minimizing signal processing gain for potential detectors.
Implementation Method 1
The microbolometers are designed to be highly absorptive in the spectral band of interest. As the microbolometers absorb the optical energy their temperature rises.
Implementation Method 2
This temperature is measured by the bolometric effect, wherein the resistance of the microbolometer is a function of its temperature.
Implementation Method 3
an oscillator configured to generate a main clock
Implementation Method 4
readout circuitry to pulse bias one or more thermal sensors of one or more of the rows and obtain output from the pulse biased thermal sensors
Data Source
AI summary
Techniques for reducing a likelihood of detection of an imaging system by another imaging system are provided. For example, the techniques may include controlling read-out such that the timings between frames of an image are non-uniform. For example, a processor may be configured to generate a plurality of frame synchronization signals from a main clock and transmit the plurality of frame synchronization signals to readout circuitry. Each frame synchronization signal is an instruction to start the biasing and reading for a respective frame. The plurality of frame synchronization signals may be generated such that a timing between pulse biasing the same thermal sensor is not uniform. The techniques may also include controlling the read-out such that the timings between lines within a frame are non-uniform which also results in the timing between pulse biasing of the same thermal sensor not being uniform.