Publications
High-efficiency large-angle Pancharatnam phase deflector based on dual-twist design
Summary
Summary
We have previously shown through simulation that an optical beam deflector based on the Pancharatnam (geometric) phase can provide high efficiency with up to 80° deflection using a dual-twist structure for polarization-state control [Appl. Opt. 54, 10035 (2015)]. In this report, we demonstrate that its optical performance is as predicted...
Optical phased-array ladar
Summary
Summary
We demonstrate a ladar with 0.5 m class range resolution obtained by integrating a continuous-wave optical phased-array transmitter with a Geiger-mode avalanche photodiode receiver array. In contrast with conventional ladar systems, an array of continuous-wave sources is used to effectively pulse illuminate a target by electro-optically steering far-field fringes. From...
Comparisons between the extended Kalman filter and the state-dependent Riccati estimator
Summary
Summary
The state-dependent Riccati equation-based estimator is becoming a popular estimation tool for nonlinear systems since it does not use system linearization. In this paper, the state-dependent Riccati equation-based estimator is compared with the widely used extended Kalman filter for three simple examples that appear in the open literature. It is...
Bioinspired resource management for multiple-sensor target tracking systems
Summary
Summary
We present an algorithm, inspired by self-organization and stigmergy observed in biological swarms, for managing multiple sensors tracking large numbers of targets. We devise a decentralized architecture wherein autonomous sensors manage their own data collection resources and task themselves. Sensors cannot communicate with each other directly; however, a global track...
Time delay integration and in-pixel spatiotemporal filtering using a nanoscale digital CMOS focal plane readout
Summary
Summary
A digital focal plane array (DFPA) architecture has been developed that incorporates per-pixel full-dynamic-range analog-to-digital conversion and orthogonal-transfer-based realtime digital signal processing capability. Several long-wave infrared-optimized pixel processing focal plane readout integrated circuit (ROIC) designs have been implemented, each accommodating a 256 x 256 30-um-pitch detector array. Demonstrated in this...
Design approaches for digitally dominated active pixel sensors: leveraging Moore's law scaling in focal plane readout design
Summary
Summary
Although CMOS technology scaling has provided tremendous power and circuit density benefits for innumerable applications, focal plane array (FPA) readouts have largely been left behind due to dynamic range and signal-to-noise considerations. However, if an appropriate pixel front end can be constructed to interface with a mostly digital pixel, it...
The digital focal plane array (DFPA) architecture for data processing "on-chip"
Summary
Summary
The digital focal plane array (DFPA) project seeks to develop readout integrated circuits (ROICs) utilizing aggressively scaled and commercially available CMOS. Along with focal plane scaling and readout robustness benefits, the DFPA architecture provides a very simple way to implement processing algorithms directly on image data, in real-time, and prior...
Using filter banks to improve interceptor performance against weaving targets
Summary
Summary
It is well known that interceptor performance against a weaving or spiraling target can be improved by use of a special purpose weave guidance law. However the weave guidance law requires knowledge of the target weave frequency. When the target weave frequency is unknown an extended Kalman filter is usually...
Normalized analysis of interceptor missiles using the four-state optimal guidance system
Summary
Summary
Performance prediction of miss distance due to sensor measurement errors and random target manuevers for missiles using proportional navigation guidance has been analyzed using the adjoint technique; a normalization technique has been usedto reduce the solution of the set of differential equations describing the proportional navigationguidance problemto a set of...
Improving the high altitude performance of tail-controlled endoatmospheric missiles
Summary
Summary
It is demonstrated that at high altitude the performance of a tail-controlled aerodynamic missile can degrade because of the existence of low frequency right-half plane zeroes in the airframe transfer function when either proportional navigation or optimal guidance is used. A new guidance law that accounts for the airframe zeroes...