Masters Theses

Date of Award

8-2001

Degree Type

Thesis

Degree Name

Master of Science

Major

Aviation Systems

Major Professor

Fred Stellar

Committee Members

Ralph D. Kimberlin, Frank S. Collins

Abstract

There is a need to measure the effects of radar jamming on modern military radar systems. An advanced Doppler video system designed to measure the effects of jammers on radar systems was developed by the United States Air Force Electronic Warfare Division. This thesis develops a methodology that can be used to effectively validate such an instrumentation system. The Doppler video instrumentation system was an advanced system geared specifically towards developing counter-jamming techniques by capturing the raw RF data entering the radarThe methodology developed was a process of sequenced tests designed to evaluate the Doppler video instrumentation system. Applications into the development of electronic counter-countermeasures are described to illustrate the processes required by this methodology.

The typical radar instrumentation connects only to the radar processor, recording the various operating modes or calculated range and closing rates of targets, and does not capture the RF spectrum. That type of system is easily validated through the comparison of radar processor data to target tracking data from a surveyed ground radar or other truth source. The challenge of validating the Doppler video instrumentation was in selecting specific tests to determine the accuracy of the frequency and intensity measurements of the RF spectrum.

The methodology used a building block approach, starting with ground tests and advancing to flight tests. Ground-testing involved direct injection of a signal into the radar, exercising the full range of bandwidth and intensity. Flight testing assessed radar baseline performance to determine the impact of the instrumentation system's insertion loss on detection and lock-on range. Flight testing included examining the effects of Doppler shifts and frequency roll-off at radar gimbal. Flight tests against a target equipped with a programmable radar jammer were designed to evaluate performance against techniques such as noise, range gate pull-off and velocity gate pull-off.

The methodology demonstrated that the Doppler video instrumentation system met the accuracy requirements for monitoring the frequency and intensity data from the radar under test in both ground and flight phases. Flight testing also successfully assessed the capability of the instrumentation system to capture jamming techniquesThe radar under test was observed in jamming runs to apply an attenuating filter to manage the power levels for the receiver and in the process lose the faint skin returnAdditional testing in an anechoic chamber or with a calibrated airborne signal collector was recommended to enhance the measurement of intensity error.

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