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Statistical Estimation and Tracking of Refractivity from Radar Clutter

Statistical Estimation and Tracking of Refractivity from Radar Clutter

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Figure 3.6: Convergence in GA: Effect <strong>of</strong> GA sample size on 1-D marginal<br />

posterior densities for a 40k Gibbs sample size. Distributions<br />

calculated using (a) exhaustive search <strong>and</strong> the hybrid method<br />

with (b) 1k, (c) 5k, <strong>and</strong> (d) 15k GA samples. . . . . . . . . . . 81<br />

Figure 3.7: Convergence in GS: Effect <strong>of</strong> GS sample size on 1-D marginal<br />

posterior densities for a 15k GA sample size. Distributions calculated<br />

using (a) exhaustive search <strong>and</strong> the hybrid method with<br />

(b) 1k, (c) 5k, <strong>and</strong> (d) 20k Gibbs samples. . . . . . . . . . . . . 82<br />

Figure 3.8: Convergence <strong>of</strong> the hybrid method. D for each parameter as<br />

a function <strong>of</strong> (a) GA sample size for a 40k Gibbs sample size<br />

<strong>and</strong> (b) Gibbs sample size for a 15k GA sample size . . . . . . . 83<br />

Figure 3.9: An example <strong>of</strong> range-dependent sixteen parameter M-pr<strong>of</strong>ile<br />

with four parameters per 20 km. Vertical pr<strong>of</strong>ile at any given<br />

range is calculated by linear interpolation <strong>of</strong> both the slopes <strong>and</strong><br />

the layer thicknesses. . . . . . . . . . . . . . . . . . . . . . . . . 84<br />

Figure 3.10: Results for the Wallops data. (a) estimated <strong>and</strong> helicoptermeasured<br />

pr<strong>of</strong>iles at various ranges <strong>and</strong> (b) SPANDAR clutter<br />

together with the clutter that one would obtain <strong>from</strong> the estimated<br />

range-dependent <strong>and</strong> independent environments. . . . . . 85<br />

Figure 3.11: Marginal <strong>and</strong> conditional distributions. (a)1-D (diagonal)<br />

<strong>and</strong> 2-D (upper diagonal) posterior probability distributions in<br />

terms <strong>of</strong> percent HPD, for the range-dependent SPANDAR data<br />

inversion. (b) Error function for conditional planes. . . . . . . . 88<br />

Figure 3.12: Posterior densities for propagation factor F at three different<br />

ranges. Color plots show the PPD <strong>of</strong> F for height values between<br />

0 m <strong>and</strong> 200 m in terms <strong>of</strong> percent HPD, with the MAP solution<br />

(dashed white). . . . . . . . . . . . . . . . . . . . . . . . . . . . 89<br />

Figure 3.13: Posterior probability densities for propagation factor F at<br />

(a) 20 <strong>and</strong> (b) 100 m altitudes. Color plots show the PPD <strong>of</strong> F<br />

for ranges between 0–90 km in terms <strong>of</strong> percent HPD, with the<br />

dashed white line showing the MAP solution. . . . . . . . . . . 92<br />

Figure 4.1: Ten 2-D M-pr<strong>of</strong>iles measured by JHU helicopter, Wallops’98<br />

experiment (gray) <strong>and</strong> best trilinear pr<strong>of</strong>ile fit for each measurement<br />

(black). . . . . . . . . . . . . . . . . . . . . . . . . . . . . 103<br />

Figure 4.2: Case study I. (a) Regional map <strong>and</strong> the location <strong>of</strong> the station<br />

(×), (b) average spring M-pr<strong>of</strong>ile, (c) 100 Monte Carlo trajectories,<br />

<strong>and</strong> (d) RMS errors <strong>of</strong> the EKF, UKF, <strong>and</strong> 200-particle<br />

PF along with the square root <strong>of</strong> the posterior CRLB. . . . . . 115<br />

Figure 4.3: Efficiency <strong>of</strong> the PF as a function <strong>of</strong> the number <strong>of</strong> particles. 117<br />

Figure 4.4: Case Study II: Temporal evolution <strong>of</strong> the range-independent<br />

duct. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 117<br />

Figure 4.5: Evolution <strong>of</strong> the highly nonlinear relative radar clutter y k<br />

(dB) computed for the true environment without w k . . . . . . . 118<br />

x

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