A technique which combines the use of pseudo-noise (pn) codecorrelation and multilateration with another technique, termed "bandwidth synthesis" (bws), to significantly enhancethe accuracy of satellite orbit determination is the focus of this project. from a theoretical viewpoint, bws allows one to… More

A differential gps ground station associated with a data link is proposed as a potential source of instrument meteorological conditions navigation data for aircraft and as a source of dependent surveillance data in support of atc operations at expeditionary air fields served by matcals. obtainable… More

A research study is proposed that will lead to the development of a robust, survivable tactical communication network based on an adaptive beam antenna system. the performance of such a network will be determined and algorithms for beam acquisition and tracking developed for point-to-point (link)… More

A navigation data reporter (navrep) which provides the best estimate of user position from available nav aids is proposed as a source oftracking data for dependent su tsurveillance in oceanic airspace or areas with atc coverage gaps. navrep algorithms are to be developed for on board or ground-based… More

A study i proposed to begin the development of a software-based tool that will be useful in the specification and/or design of satellite communications at shf and ehf through nuclear-induced scintillation. the two prime objectives of the study are (1) to characterize the scintillation environment… More

An exploratory and innovative application of expert system methodology is proposed in which the framework is laid for the control of multiple expert system in a hierarchically structured architecture. the resulting system represents a flexible, adaptable mission support tool with broad spectrum… More

The stated power and bandwidth efficiency requirements dictate the use of a phase-coherent modulation format. recently, there has been intensive research into a variety of integrated coding/modulation systems, such as ungerboeck codes, trellis coding, and continuous phase modulation, which offer… More

High speed, high fidelity digital communication links have adire need for signal processing techniques that can reduce transmitter power requirements. one potential technique is convolutional coding coupled with viterbi algorithm (va) decoding. state-of-the-art va decoders can provide 5.0 db of… More

To support the increasing accuracy, speed and efficiency requirements of the orbit determination process for future low earth orbiting spacecraft missions, a growing need for improved signal processing techniques is becoming apparent. a principal need is the significant reduction in pseudo-noise… More

This project concerns a technique which combines the inherent time benefits of an analytic modeling approach for investigating communication channels with the flexibility of a monte carlo direct simulation approach into a single integrated software package. the resultant mathematical modeling tool… More

A methodology for evaluating satellite system survivability (as a function of control autonomy) is proposed. the methodology combines the proven effectiveness of analysis and simulation techniques for assessing jamming, nuclear scintillation and physical threats under control and guidance of an… More

There is a growing need to actively monitor radio communication channels and receiver circuits for the presence of intentional or unintentional interference that may degrade link quality. the multiplicity of signal formats and interference types makes the task of developing robust monitoring… More

Expert system technology is growing rapidly. commercially available packages (general purpose inference engines, knowledge/data representation schemes and development environments) are multiplying. custom real-time expert systems are now being fielded. real-time features are being added to general… More