When
April 8, 2026, 2:30 – 5:30 a.m.
Where
Meinel 821
Title
Coherent Effects And Radiometry Considerations In Active Imaging
Abstract
Active imaging employs coherent laser illumination to form images from target-reflected photons, enabling improved performance in long-range, low-light, and degraded visual environments compared to passive systems. These gains come with increased system complexity and additional noise sources that must be quantified to demonstrate performance benefits. System performance is governed by resolution and sensitivity, both of which degrade in the presence of focal-plane motion, or line-of-sight (LOS) jitter, leading to image blur and signal spreading.
This dissertation investigates three primary contributors to LOS jitter: radiometric jitter driven by signal-to-noise ratio (SNR), turbulence-induced jitter, and coupling between turbulence and speckle. We derive general SNR expressions for laser range-gated systems with range-dependent divergence and receiver zoom, enabling prediction of radiometric jitter. We develop single-integral solutions in the weak-to-moderate scintillation regime for noise-equivalent angle (NEA) and G-tilt/C-tilt error, yielding validated scaling laws. A scaled laboratory experiment reproduces representative speckle and turbulence statistics, confirming theory and informing an integrated error budget for active imaging performance.
Please email Jini at jini@optics.arizona.edu or Eric at emitchell1@arizona.edu for a Zoom link.