Physics-guided neural network for predicting chemical signatures.

Achieving high classification accuracy on trace chemical residues in active spectroscopic sensing is challenging due to the limited amount of training data available to the classifier. Such classifiers often rely on physics-based models for generating training data though these models are not always accurate when compared to measured data. To overcome this challenge, we developed a physics-guided neural network (PGNN) for predicting chemical reflectance for a set of parameterized inputs that is more accurate than the state-of-the-art physics-based signature model for chemical residues.

Band selection method for subpixel target detection using only the target reflectance signature.

While offering powerful capabilities, the high dimensionality of hyperspectral images can make information extraction a challenge. For that reason, dimension reduction is a common data processing step. For the purpose of subpixel target detection, band selection is a dimension reduction method that can optimize results as well as reduce computation costs.

Separability between pedestrians in hyperspectral imagery.

The popularity of hyperspectral imaging (HSI) in remote sensing continues to lead to it being adapted in novel ways to overcome challenging imaging problems. This paper reports on research efforts exploring the phenomenology of using HSI as an aid in detecting and tracking human pedestrians. An assessment of the likelihood of distinguishing between pedestrians based on the measured spectral reflectance of observable materials and the presence of noise is presented.

Adaptive target detection with a polarization-sensitive optical system.

We developed an adaptive polarimetric target detector (APTD) to determine the optimum combination strategy for a multichannel polarization-sensitive optical system. The proposed algorithm is based on scene-derived polarization properties of the target and background, and it seeks to find an optimum multichannel combination of linear polarizing filters that maximizes the signal-to-clutter ratio (SCR) in intensity and Stokes parameter images. The algorithm is validated by performing RX anomaly detection and a generalized likelihood ratio test on both synthetic and real imagery.