Publications

This report describes several scheduling algorithms that may form part of the interrogation management function of a discrete address beacon system. These include scheduling algorithms that can handle unequal message lengths and types which can schedule a message very rapidly (dynamic scheduling). The algorithms are evaluated in terms of the...

This report presents a novel procedure for determining the accuracy of range-range (or spherical) multilateration systems. The procedure is a generalization of one previously described for hyperbolic multilateration systems. A central result is a demonstration that the inverse of the covariance matrix for positional errors corresponds to the moment of...

In the application of the Discrete Address Beacon System (DABS) concept to Air Traffic Control (ATC) surveillance, estimates of aircraft position must be made using as few replies as possible, preferably one. This requires the use of monopulse techniques. Since the beacon system provides high signal-to-noise ratios (SNR), the fundamental...

This report reviews the performance of operational ASR's, discusses each type of clutter with which the target must compete, examines presently employed methods of overcoming clutter and several state-of-the-art techniques which have not found their way into the ASR's for one reason or another. It concludes by describing two radars...

Increased air traffic coupled with the proliferation of sophisticated avionics can be expected to stimulate increased demand for air traffic control (ATC) services over the next few decades. New challenges for the design of communication, surveillance, and navigation subsystems is an anticipated consequence. Since it is unlikely that significantly larger...

The effects of sensor accuracy, data rate, and message delivery delay upon automated conflict detection,and resolution processing is analyzed and particular considerations for DABS/IPC operation are discussed. Various options in the design of the algorithmic logic are enumerated and a particular logic is chosen for quantitative inspection. Performance sensitivity calculations...

Long-range surveillance radars use MTI techniques to detect moving targets in a clutter background. The transmitter PRF is usually staggered to eliminate the blind speeds due to aliasing of the target and clutter spectra. A spectral analysis of the target and clutter signals is performed for the case of nonuniform...

In the report, "A Theory for Optimal MTI Digital Signal Processing. Part I. Receiver Synthesis," (1), the problem of eliminating scanning ground clutter from an aircraft surveillance radar was examined from a statistical decision theoretical point of view. An optimum processor was derived which could be approximated by a clutter...

The performance of three candidate modulation schemes for DABS is analyzed in this report and a comparison on the basis of probability of error per bit is made. The three types of modulation are PAM, DPSK, and FSK. The results show that, at a given level of interference and signal-to-noise...

This report investigates the requirements imposed on a surveillance system for supporting independent approaches to closely spaced parallel runways. Based on a proposed procedure for monitoring aircraft approach paths and controlling deviations from proper approach paths, the required spacing between runway centerlines is derived as a function of surveillance system...