High-Resolution Wide-Swath Spectrometer Using an Inverted Image Slicer
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Fourier transform spectrometers used in satellites suffer from poor spectral resolution at wide angles, and moving elements like whiskbroom configurations increase cost and complexity.
Innovation Solution
A spectrometer design incorporating an inverted image slicer and an adjustable interferometer to convert a linear field of view into a two-dimensional grid on a sensor, using a two-dimensional array of pixels for improved spectral resolution.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a moving element such as used in a whiskbroom configuration is used to sweep across a range of viewing angles, then the viewing angle range is improved, but the cost and complexity of the spectrometer increase
Solution Approach 1:
The linear field of view is divided into multiple discrete angular positions that are simultaneously imaged onto the two-dimensional sensor grid. Each pixel or pixel group corresponds to a specific viewing angle, eliminating the need for mechanical sweeping while maintaining wide angular coverage.
Solution Approach 2:
The spectrometer transitions from a one-dimensional linear field of view to a two-dimensional grid on the sensor. This dimensional transformation allows simultaneous capture of multiple viewing angles across the wide swath without requiring mechanical movement, thereby reducing complexity while expanding adaptability.
2Adaptability or versatility
If Fourier transform spectrometers are used at wide angles, then the spectral resolution deteriorates
Solution Approach 1:
Different regions of the two-dimensional sensor grid are optimized for different viewing angles. The optical path and interferometer configuration are designed to maintain consistent spectral resolution across all angular positions by locally adjusting the imaging properties for each region of the field of view.
Solution Approach 2:
The system maintains spectral resolution by adjusting optical parameters such as the path difference in the interferometer and the imaging geometry to compensate for the effects of wide viewing angles. This allows the spectrometer to operate across a wide angular range without sacrificing measurement precision.
3Measurement precision
If an inverted image slicer converts a linear field of view to a two-dimensional grid, then the spectral resolution is improved, but the device complexity increases
Solution Approach 1:
The inverted image slicer combines multiple optical functions into a single integrated component. It simultaneously performs field of view transformation, angular dispersion, and spectral imaging, thereby achieving high spectral resolution without proportionally increasing overall system complexity.
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
Achieves better spectral resolution than 2 cm^-1 with a range of wavelengths including 6.2 micrometers, converting a field of view across 100 milliradians to less than 90 milliradians, enhancing spectral analysis capabilities.
Implementation Method 1
an inverted image slicer comprising a first lens to focus input light onto a first plurality of mirrors
Implementation Method 2
each of the first plurality of mirrors is configured to direct light from the first lens to a corresponding mirror of a second plurality of mirrors
Implementation Method 3
an adjustable interferometer configured to accept light from the inverted image slicer
Implementation Method 4
a sensor configured to sense light from the interferometer
Data Source
Figure 1~2
Figure 3
Figure 4
AI summary
Technologies for a high resolution and wide swath spectrometer are disclosed. In the illustrative embodiment, an inverted image slicer converts a linear field of view into a grid shape, allowing for an interferometer of a Fourier transform spectrometer to operate on a narrow range of field of views, improving the average spectral resolution of the spectrometer.