Kyle Novak

Range performance of the DARPA AWARE wide field-of-view visible imager

In a prior paper, we described a new imaging architecture that addresses the need for wide field-of-view imaging combined with the resolution required to identify targets at long range. Over the last two years substantive improvements have been made to the system, both in terms of the size, weight, and power of the camera as well as to the optics and data management software. The result is an overall improvement in system performance, which we demonstrate via a maritime target identification experiment.

Imaging with multi-spectral mosaic-array cameras.

The emerging class of multi-spectral mosaic-array cameras combines opportunities of spectral data processing and full-motion video color display. We explore capabilities of such sensors and propose the novel demosaicking algorithm capable of enhancing resolution of equally sampled multi-spectral mosaic imagery. We present experimental results of the proposed processing using the imagery acquired with a nine-band short-wave infrared mosaic-array camera.

Super-Resolution Based Demosaicking For Full Motion Video SWIR Multi-Spectral Sensor

We present novel demosaicking algorithm for the first full motion video SWIR 9-band sensor based on pixel size filter array. Spatial resolution enhancement of each spectral band is achieved using modified super-resolution technique.

Demosaicking for full motion video 9-band SWIR sensor

Short wave infrared (SWIR) spectral imaging systems are vital for Intelligence, Surveillance, and Reconnaissance (ISR) applications because of their abilities to autonomously detect targets and classify materials. Typically the spectral imagers are incapable of providing Full Motion Video (FMV) because of their reliance on line scanning. We enable FMV capability for a SWIR multi-spectral camera by creating a repeating pattern of 3x3 spectral filters on a staring focal plane array (FPA). In this paper we present the imagery from an FMV SWIR camera with nine discrete bands and discuss image processing algorithms necessary for its operation. The main task of image processing in this case is demosaicking of the spectral bands i.e. reconstructing full spectral images with original FPA resolution from spatially subsampled and incomplete spectral data acquired with the choice of filter array pattern. To the best of authors knowledge, the demosaicking algorithms for nine or more equally sampled bands have not been reported before. Moreover all existing algorithms developed for demosaicking visible color filter arrays with less than nine colors assume either certain relationship between the visible colors, which are not valid for SWIR imaging, or presence of one color band with higher sampling rate compared to the rest of the bands, which does not conform to our spectral filter pattern. We will discuss and present results for two novel approaches to demosaicking: interpolation using multi-band edge information and application of multi-frame super-resolution to a single frame resolution enhancement of multi-spectral spatially multiplexed images.

Application of rich feature descriptors to small target detection in wide-area persistent ISR systems

One of the desired capabilities for wide-area persistent ISR systems is to reliably locate and subsequently track the movement of targets within the field of view. Current wide-area persistent ISR systems are characterized by large pixel overall counts and very large fields of view. This leads to a large ground sample distance with few pixels-on-target. Locating targets under these constraints is extremely difficult due to the fact that the targets present very little detailed structure. In this paper we will present the application of rich image feature descriptors combined with advanced statistical target detection methodologies to the airborne ISR problem. We will demonstrate that these algorithms can reliably locate targets in the scene without relying on the targets motion to form a detection. This is useful in ISR application where it is desirable to be able to continuously track a target through stops and maneuvers.

Optical Signatures and Detection Strategy for a Finned Bioinspired Unmanned Undersea Vehicle

The surface expressions for a submerged finned bioinspired unmanned underwater vehicle (UUV) were examined using VNIR and longwave infrared sensors as the system maneuvered in laboratory and field environments. Laboratory experiments revealed that the eddies generated by the flapping of the finned propulsion and attitude control system initially appeared as discrete thermal boils on the water surface. As these boils evolved, expanded, and merged into one another, two parallel thermal tracks were observed. The tracks cross-linked forming a single thermal swath or footprint behind the trajectory of the vehicle. Similar thermal disruptions were observed when experiments were performed in an uncontrolled harbor environment under daytime and nighttime lighting conditions. Estimates for the background clutter, system signal, and detection statistic were generated using probabilistic models to demonstrate the feasibility of extracting signals from complex environments in both laboratory and harbor experiments. Performance of the detection model was presented in the form of receiver operating characteristic curves. Results clearly demonstrate that we can achieve > 99% probability of detecting the presence of the UUV with a very low probability of false alarm (< 0.005%) in a real harbor environment, where we estimate

Pulsed holographic system for imaging through spatially extended scattering media

\text{signal-to-noise ratio}=21.5

Increasing Resolution of Multi-Spectral Mosaic-Array Cameras

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9-band SWIR multispectral sensor providing full-motion video

Imaging through scattering media is a highly sought capability for military, industrial, and medical applications. Unfortunately, nearly all recent progress was achieved in microscopic light propagation and/or light propagation through thin or weak scatterers which is mostly pertinent to medical research field. Sensing at long ranges through extended scattering media, for example turbid water or dense fog, still represents significant challenge and the best results are demonstrated using conventional approaches of time- or range-gating. The imaging range of such systems is constrained by their ability to distinguish a few ballistic photons that reach the detector from the background, scattered, and ambient photons, as well as from detector noise. Holography can potentially enhance time-gating by taking advantage of extra signal filtering based on coherence properties of the ballistic photons as well as by employing coherent addition of multiple frames. In a holographic imaging scheme ballistic photons of the imaging pulse are reflected from a target and interfered with the reference pulse at the detector creating a hologram. Related approaches were demonstrated previously in one-way imaging through thin biological samples and other microscopic scale scatterers. In this work, we investigate performance of holographic imaging systems under conditions of extreme scattering (less than one signal photon per pixel signal), demonstrate advantages of coherent addition of images recovered from holograms, and discuss image quality dependence on the ratio of the signal and reference beam power.

Video rate nine-band multispectral short-wave infrared sensor

We present approaches to spatial resolution recovery of multi-spectral mosaic-array sensors based on pixel size filter arrays. Resolution enhancement is demonstrated using imagery collected with 9-band SWIR full motion video camera.