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This study investigates the real life feasibility of applying modern estimation theory to target angular measurement information provided by a short to medium range, lightweight, tactical, tracking radar. Techniques are considered in terms of their computational demand and their effectiveness in filtering practically obtained measurement data. With the aid of a mathematical model, the angular measurement operation of the radar is shown to be unlikely to provide the desired measurement information for these operating conditions. This deficiency is due to multisource noise and encompasses such well known phenomena as glint. Analysis of measurement data obtained from T.V. and radar trials conducted using the Marconi ST802 radar to track a light aircraft, demonstrates these phenomena. Standard Kalman solutions proposed in the literature are applied to these measurements and shown to be ineffective against multisource noise. Consequently modifications are proposed and shown to be considerably more effective. The Success of these modifications led to their application to a low elevation angle tracking example, where multisource noise can severely degrade the performance of the radar. As a result, further tests with low angle data are recommended.

The investigation of the high-latitude aurora by means of the V.H.F. auroral radar SABRE, (Swedish And British auroral Radar Experiment), developed by the Leicester University Ionospheric Physics group, is described. The first two chapters review previous studies of the atmosphere by radar techniques and includes a description of the SABRE radar. The basic radar equation and velocity relationships are derived and the various loss factors examined. From analysis of the echo signal data for the diffuse aurora, and examination of signal data from a radio star, the SABRE radar parameters are established. An investigation is then undertaken of the variation of the electrojet parameters, (derived from application of the radar equation to the SABRE data), with height, electric field strength and geomagnetic conditions. Evidence is found of backscattering from irregularities generated by both two-stream and gradient drift processes. An examination is also made of the echo signals detected at relatively short ranges, of below 370 km, and several causal mechanisms are investigated including scattering processes in the neutral atmosphere. It is evident that aircraft are predominantly the cause of these short-range echoes. This investigation also reveals a number of software and hardware faults in the initial radar configuration. This Thesis is concluded with suggestions for future development of the radar system, which include the implementation of a height-finding facility and improved spectral resolution.

Remote sensing is becoming an increasingly important tool for ocean wave measurement, and over the past decade much progress has been made in the development of the wave measuring capabilities of HF (High Frequency) radar. This system is able to make detailed and near continuous observations of the sea surface over a wide area. However, because the mathematics of the data extraction process is rather difficult, the statistical properties of the observed data have to date been poorly understood. In this study, the approximate sampling distributions of a variety of measurements from HF radar (including significant waveheight, mean wave period, wind direction, and various spectral parameters) are derived in terms of quantities that are either known or estimable. The resulting confidence intervals are, in the case of significant waveheight and mean wave period, of comparable width to those obtained from the corresponding NURWEC2 (Netherlands UK Radar Wave buoy Experimental Comparison) wave buoy measurements, and in the case of spectral power, they are narrower. Furthermore, methods are derived by which such radar measurements may be compared with their corresponding wave buoy measurements in a statistically valid manner, and their relative biases estimated. These methods are then applied to data taken during the NURWEC2 field trial, which suggest that the radars and the wave buoy show good correspondence for measurements of significant waveheight and of spectral power (over 85 - 125mHz - the frequencies with most wave power, and hence those of most importance). There is also a fair correspondence for mean period measurements in the range 6.8 - 11.0secs. Spectral mean direction shows good correspondence over 85 - 155mHz over the somewhat limited directional range (i. e. as observed during the NURWEC2 storm) of the data.

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