Compact SAL Seeker Calibration Using Fixed Optical Array
Solution Overview
Problem
Current methods for calibrating semi-active laser (SAL) seekers are expensive and time-consuming, requiring a 3-axis stage and a single Q-switched laser, resulting in high costs and prolonged calibration times, especially as field-of-view and fidelity specifications increase.
Innovation Solution
A compact test station using an array of fixed optical sources positioned on a spherical lens, which collimates divergent beams to cover the entire field-of-view without a 3-axis stage, allowing for rapid and cost-effective calibration of SAL seekers and other electro-optic sensors.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a 3-axis stage and single Q-switched laser are used for calibration, then measurement precision is maintained, but calibration time and cost increase significantly
Solution Approach 1:
The patent divides the calibration system into multiple fixed optical sources arranged in an array, each representing a specific field-of-view position. This segmentation allows simultaneous illumination of multiple calibration points without requiring mechanical movement, thereby reducing calibration time while maintaining precision through the fixed geometric arrangement of sources
Solution Approach 2:
The optical sources are pre-positioned at fixed locations corresponding to specific angular positions in the field of view. This preliminary positioning eliminates the need for real-time mechanical adjustment during calibration, as all calibration points are already prepared in their correct spatial relationships before the calibration process begins
2Measurement precision
If a 3-axis stage and single Q-switched laser are used for calibration, then measurement precision is maintained, but device complexity and cost increase
Solution Approach 1:
The patent extracts and eliminates the complex 3-axis mechanical stage from the calibration system. Instead of using a single movable laser that requires precise mechanical positioning, the system uses multiple fixed optical sources whose positions are determined by simple geometric arrangement, thereby reducing device complexity while maintaining calibration precision
Solution Approach 2:
The patent replaces the expensive single Q-switched laser with multiple inexpensive fixed optical sources. These simpler, lower-cost sources are arranged in a fixed array, eliminating the need for expensive mechanical positioning systems while achieving the same calibration functionality
3Measurement precision
If field-of-view and fidelity specifications are increased, then measurement precision improves, but calibration time and cost increase proportionally
Solution Approach 1:
The patent segments the field of view into multiple discrete angular positions, each covered by a fixed optical source in the array. This segmentation allows the entire field of view to be calibrated simultaneously or in rapid sequence without mechanical movement, enabling high-fidelity calibration across wide fields of view while maintaining high throughput
Solution Approach 2:
The patent transitions from a single-dimensional mechanical scanning approach to a multi-dimensional fixed array configuration. By arranging optical sources in a spatial array corresponding to different angular positions, the system covers the entire field of view in a single static configuration, eliminating the time penalty associated with increasing field-of-view specifications
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 solution significantly reduces calibration time and cost, achieving a throughput that is at least three orders of magnitude faster and more cost-effective than traditional methods while maintaining performance, with the ability to fit on an optical bench.
Implementation Method 1
The spherical lens collimates divergent beams to form a collimated beam that covers the entire field-of-view
Implementation Method 2
The spherical lens comprises one or more materials each having an index of refraction greater than one and less than or equal to two
Data Source
AI summary
A fixed-source array test station provides a compact cost-effective high-throughput test bed for testing optical sensors that require stimulus at fixed angular positions. An array of fixed collimated sources at different angular positions in the sensor's FOV are positioned on a surface of a focal sphere at the effective focal length of a spherical lens and aligned along respective radial lines to the center of the spherical lens so that each said divergent optical beam is collimated by the spherical lens to form a collimated optical beam that overlaps the entire entrance pupil of the optical seeker. The sources are activated in accordance with an activation profile in order to calibrate or otherwise test the sensor.