David So Keung Chan

Spatial-processing techniques for the detection of small targets in IR clutter

The detection of small targets in infrared (IR) clutter is a problem of critical importance to Infrared Search and Track (IRST) systems. This paper presents techniques for analyzing and improving the detection performance of IRST systems. Only spatial, or single-frame, processing will be addressed. For clutter with spatially slowly varying statistics, the approach is based on linear filtering. Models of target and cluttter are developed and used to analyze matched filter performance and sensitivity. This sensitivity analysis is used to improve filter bank design. A clutter classification scheme which can separate clutter of different types is presented. Finally, to improve system performance in the presence of large intensity gradients, such as cloud edges, an improved adaptive threshold scheme is presented.© (1990) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

Trajectory synchronization and negotiation in Trajectory Based Operations

Trajectory Based Operations (TBO) is a key component of both the US Next Generation Air Transport System (NextGen) and Europes Single European Sky ATM Research (SESAR). There is a significant amount of effort underway in both programs to advance this concept. Trajectory Synchronization and Negotiation are key required capabilities in both the NextGen and SESAR TBO concepts, and they provide the framework to improve the efficiency of airspace operations. In recognition of the importance of TBO, General Electric and Lockheed Martin have created a Joint Strategic Research Initiative (JSRI), which aims to generate technologies that accelerate adoption of TBO. This paper explores various trajectory synchronization and negotiation concepts, including existing gaps and shortfalls. This paper also presents the JSRI simulation and evaluation environment being developed, which embeds trajectory synchronization and negotiation concepts, and has the potential to address existing gaps and shortfalls.

Enabling Trajectory Based Operations through Air-Ground Data Exchange

Trajectory Based Operations (TBO), a key concept in the US Next Generation Air Transportation System (NextGen) and in Europe’s Single European Sky ATM Research (SESAR), allows for more efficient planning and execution of flight plans. The basis for TBO is to plan and perform operations using a shared view of the flight that takes into account user preferences and is expressed by a four-dimensional (4D) trajectory. Interoperability issues, due to dissimilar requirements that trajectories need to satisfy in the various automation systems involved in air traffic management, could limit the efficiency gains expected from TBO. Recognizing the importance to TBO of advancing trajectory synchronization and negotiation technologies, Lockheed Martin, GE Aviation Systems and GE Global Research have joined forces to develop and test trajectory synchronization strategies. We identified the steps and specific messages that need to be exchanged in order to resolve discrepancies between the trajectory used by the Flight Management System (FMS) to guide the aircraft and the trajectory used by Air Traffic Control (ATC) ground automation systems. Using real world FMS and ATC systems we developed trajectory synchronization and negotiation algorithms and methods to integrate the FMS trajectory directly into the ground automation systems used by ATC. The FMS trajectory takes into account operator preferences and has the benefit of the high fidelity aircraft performance models and flight specific parameters that affect the trajectory. In the process of synchronizing the air-ground trajectories, all the advantages of the FMS trajectory are now available to ground automation.

Air-ground trajectory synchronization — Metrics and simulation results

It has been established that Trajectory Based Operations are a key component of future Air Traffic Management systems as currently underway in the United States with NextGen and Europe with SESAR. One of the major goals of Trajectory Based Operations is to provide participants accurate 4-Dimensional Trajectories predicting the future location of the aircraft with a high level of certainty. This is not realizable without improving the coordination and interoperability of air and ground systems. By leveraging GEs Flight Management System and aircraft expertise with Lockheed Martins Air Traffic Control domain expertise, including the En Route Automation Modernization system, a research initiative has been formed to explore and evaluate means of better integrating air and ground systems to bring airspace operations closer to the business-optimal goal in a safe and efficient manner. The two main components of this effort are trajectory synchronization and trajectory negotiation. Trajectory synchronization will essentially result in a more complete flight plan in the air and a more accurate trajectory representation on the ground, which is a prerequisite for trajectory negotiation. This paper briefly discusses the high-level trajectory synchronization algorithm and its implementation in a fast-time simulation environment that incorporates actual Flight Management and Air Traffic Control software. It then focuses on the analysis of metrics and simulation results from several case studies. The conclusion of these studies shows that implementation of the trajectory synchronization algorithm using Controller-Pilot Data Link Communications messages as well as the Automatic Dependent Surveillance-Contract service (including the Extended Projected Profile application) achieves consistent trajectory predictions between the air and ground systems.

A high speed static CMOS PLA architecture

A static CMOS programmable-logic-array (PLA) architecture has been developed that enables the realization of high-speed control circuits while at the same time providing the low static power consumption inherent in CMOS technology. The PLA uses a novel circuit configuration and a two-phase clock to latch data between the AND and the OR planes. An 8-input, 13-output, 42-minterm finite state machine has been realized using an automatic generating system, in an area of 0.36 mm/sup 2/. This structure operates from near DC to above 80 MHz.<<ETX>>