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High resolution frequency to time domain transformations applied to the stepped carrier mris measurements
| Content Provider | NASA Technical Reports Server (NTRS) |
|---|---|
| Author | Ardalan, Sasan H. |
| Copyright Year | 1992 |
| Description | Two narrow-band radar systems are developed for high resolution target range estimation in inhomogeneous media. They are reformulations of two presently existing systems such that high resolution target range estimates may be achieved despite the use of narrow bandwidth radar pulses. A double sideband suppressed carrier radar technique originally derived in 1962, and later abandoned due to its inability to accurately measure target range in the presence of an interfering reflection, is rederived to incorporate the presence of an interfering reflection. The new derivation shows that the interfering reflection causes a period perturbation in the measured phase response. A high resolution spectral estimation technique is used to extract the period of this perturbation leading to accurate target range estimates independent of the signal-to-interference ratio. A non-linear optimal signal processing algorithm is derived for a frequency-stepped continuous wave radar system. The resolution enhancement offered by optimal signal processing of the data over the conventional Fourier Transform technique is clearly demonstrated using measured radar data. A method for modeling plane wave propagation in inhomogeneous media based on transmission line theory is derived and studied. Several simulation results including measurement of non-uniform electron plasma densities that develop near the heat tiles of a space re-entry vehicle are presented which verify the validity of the model. |
| File Size | 4629367 |
| Page Count | 133 |
| File Format | |
| Alternate Webpage(s) | http://archive.org/details/NASA_NTRS_Archive_19920018277 |
| Archival Resource Key | ark:/13960/t3b042r3c |
| Language | English |
| Publisher Date | 1992-06-24 |
| Access Restriction | Open |
| Subject Keyword | Communications And Radar High Resolution Fourier Transformation Radar Data Signal To Noise Ratios Continuous Wave Radar Reentry Vehicles Computerized Simulation Frequencies Plasma Density Rangefinding Narrowband Wave Propagation Plane Waves Signal Processing Double Sideband Transmission Ntrs Nasa Technical Reports Server (ntrs) Nasa Technical Reports Server Aerodynamics Aircraft Aerospace Engineering Aerospace Aeronautic Space Science |
| Content Type | Text |
| Resource Type | Technical Report |
