Spectral imaging is a powerful tool for providing in situ material classification across a spatia... more Spectral imaging is a powerful tool for providing in situ material classification across a spatial scene. Typically, spectral imaging analyses are interested in classification, though often the classification is performed only after reconstruction of the spectral datacube. We present a computational spectral imaging system, the Adaptive Feature-Specific Spectral Imaging Classifier (AFSSI-C), which yields direct classification across the spatial scene without reconstruction of the source datacube. With a dual disperser architecture and a programmable spatial light modulator, the AFSSI-C measures specific projections of the spectral datacube which are generated by an adaptive Bayesian classification and feature design framework. We experimentally demonstrate multiple order-of-magnitude improvement of classification accuracy in low signal-to-noise (SNR) environments when compared to legacy spectral imaging systems.
Page 1. Scene-Based Nonuniformity Correction Method Using Constant-Range: Performance and Analysi... more Page 1. Scene-Based Nonuniformity Correction Method Using Constant-Range: Performance and Analysis Sergio N. Torres Department of Electrical Engineering University of Concepcion Concepcion - Chile Rodrigo A. Reeves ...
Optical Fabrication, Metrology, and Material Advancements for Telescopes, 2004
The Gemini telescopes were designed to be infrared-optimized. Among the features specified for op... more The Gemini telescopes were designed to be infrared-optimized. Among the features specified for optimal performance is the use of silver-based coatings on the mirrors. The feasibility study contracted by Gemini in 1994-1995 provided both techniques and recipes to apply these high-reflectivity and low-emissivity films. All this effort is now being implemented in our coating plants. At the time of the study, sputtering experiments showed that a reflectivity of 99.1% at 10mum was achievable. We have now produced bare and protected silver sputtered films in our coating plants and conducted environmental testing, both accelerated and in real-life conditions, to assess the durability. We have also already applied, for the first time ever, protected-silver coatings on the main optical elements (M1, M2 and M3) of an 8-m telescope. We report here the progress to date, the performance of the films, and our long-term plans for mirror coatings and maintenance.
System requirements for many military electro-optic and IR camera systems reflect the need for bo... more System requirements for many military electro-optic and IR camera systems reflect the need for both wide-field-of-view situational awareness as well as high-resolution imaging for target identification. In this work we present a new imaging system architecture designed to perform both functions simultaneously and the AWARE 10 camera as an example at visible wavelengths. We first describe the basic system architecture and user interface followed by a laboratory characterization of the system optical performance. We then describe a field experiment in which the camera was used to identify several maritime targets at varying range. The experimental results indicate that users of the system are able to correctly identify ~10 m targets at between 4 and 6 km with 70% accuracy.
ABSTRACT We describe the calibration challenges associated with a computational spectral imaging ... more ABSTRACT We describe the calibration challenges associated with a computational spectral imaging classifier and present initial experimental results. We also discuss planned system improvements to address these calibration challenges and observed performance issues.
Fixed-pattern noise is a common feature in several uncalibrated imaging systems, and it typically... more Fixed-pattern noise is a common feature in several uncalibrated imaging systems, and it typically appears as striping and grid-like nonuniformity artifacts in hyperspectral and infrared cameras. In this work, we present a quantitative and comparative analysis of fixed ...
Spectral imaging is a powerful tool for providing in situ material classification across a spatia... more Spectral imaging is a powerful tool for providing in situ material classification across a spatial scene. Typically, spectral imaging analyses are interested in classification, though often the classification is performed only after reconstruction of the spectral datacube. We present a computational spectral imaging system, the Adaptive Feature-Specific Spectral Imaging Classifier (AFSSI-C), which yields direct classification across the spatial scene without reconstruction of the source datacube. With a dual disperser architecture and a programmable spatial light modulator, the AFSSI-C measures specific projections of the spectral datacube which are generated by an adaptive Bayesian classification and feature design framework. We experimentally demonstrate multiple order-of-magnitude improvement of classification accuracy in low signal-to-noise (SNR) environments when compared to legacy spectral imaging systems.
Page 1. Scene-Based Nonuniformity Correction Method Using Constant-Range: Performance and Analysi... more Page 1. Scene-Based Nonuniformity Correction Method Using Constant-Range: Performance and Analysis Sergio N. Torres Department of Electrical Engineering University of Concepcion Concepcion - Chile Rodrigo A. Reeves ...
Optical Fabrication, Metrology, and Material Advancements for Telescopes, 2004
The Gemini telescopes were designed to be infrared-optimized. Among the features specified for op... more The Gemini telescopes were designed to be infrared-optimized. Among the features specified for optimal performance is the use of silver-based coatings on the mirrors. The feasibility study contracted by Gemini in 1994-1995 provided both techniques and recipes to apply these high-reflectivity and low-emissivity films. All this effort is now being implemented in our coating plants. At the time of the study, sputtering experiments showed that a reflectivity of 99.1% at 10mum was achievable. We have now produced bare and protected silver sputtered films in our coating plants and conducted environmental testing, both accelerated and in real-life conditions, to assess the durability. We have also already applied, for the first time ever, protected-silver coatings on the main optical elements (M1, M2 and M3) of an 8-m telescope. We report here the progress to date, the performance of the films, and our long-term plans for mirror coatings and maintenance.
System requirements for many military electro-optic and IR camera systems reflect the need for bo... more System requirements for many military electro-optic and IR camera systems reflect the need for both wide-field-of-view situational awareness as well as high-resolution imaging for target identification. In this work we present a new imaging system architecture designed to perform both functions simultaneously and the AWARE 10 camera as an example at visible wavelengths. We first describe the basic system architecture and user interface followed by a laboratory characterization of the system optical performance. We then describe a field experiment in which the camera was used to identify several maritime targets at varying range. The experimental results indicate that users of the system are able to correctly identify ~10 m targets at between 4 and 6 km with 70% accuracy.
ABSTRACT We describe the calibration challenges associated with a computational spectral imaging ... more ABSTRACT We describe the calibration challenges associated with a computational spectral imaging classifier and present initial experimental results. We also discuss planned system improvements to address these calibration challenges and observed performance issues.
Fixed-pattern noise is a common feature in several uncalibrated imaging systems, and it typically... more Fixed-pattern noise is a common feature in several uncalibrated imaging systems, and it typically appears as striping and grid-like nonuniformity artifacts in hyperspectral and infrared cameras. In this work, we present a quantitative and comparative analysis of fixed ...
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Papers by Esteban Vera