Late metal–silicate separation on the IAB parent asteroid: Constraints from combined W and Pt isotopes and thermal modelling
Earth and Planetary Science Letters Elsevier BV 482 (2018) 490-500
Computational Microscopy at 5 Meters using Symmetric Fourier Sampling
Nowicki, Keith Joseph. "Computational Microscopy at 5 Meters using Symmetric Fourier Sampling." PhD diss., University of Colorado at Boulder, 2018.
Abstract:
Robotic planetary exploration relies upon a suite of scientific instruments to measure and record the environment under study, with the most ubiquitous instrument being some form of imager. This work describes the development of a microscope that can be mounted to the mast of planetary rover and obtain images with 10 μm spatial resolution at an unprecedented 5 meter distance. Rather than using traditional optics to generate images on a 2D focal plane array, this “remote microscope” uses a computation imaging technique to reconstruct images of targets. A set of four electronically programmable, frequency-shifted collimated laser beams that are symmetric about the axis of the optical system are projected to overlap at a distance of 5 meters and generate moving interference fringes which are used to probe the matched spatial Fourier components of the 2D intensity reflectivity function of the target surface. By probing and collecting a large set of these Fourier measurements, an image of the target is reconstructed using Fourier synthesis. This document provides a detailed description of the optical designs, electronic control requirements,
opto-mechanical structures, operational conditions and algorithmic techniques used to generate a functioning computational remote microscope. I describe and analyze a novel optical design capable of achieving the operational requirements of the system and derive the optical parameters and relevant aberrations. A novel optical surface testing technique useful for high departure aspheres is derived and demonstrated with experimental measurements. I describe in detail the optical procedures and electronics components of the laboratory implementation of the computational microscope. I report the images obtained using the microscope of scattering and reflective targets. Finally, calculation of the effects of a turbulent atmosphere on the operation of the microscope are derived and demonstrated with experimental data, and a new approach to measuring the turbulent atmosphere was developed.
opto-mechanical structures, operational conditions and algorithmic techniques used to generate a functioning computational remote microscope. I describe and analyze a novel optical design capable of achieving the operational requirements of the system and derive the optical parameters and relevant aberrations. A novel optical surface testing technique useful for high departure aspheres is derived and demonstrated with experimental measurements. I describe in detail the optical procedures and electronics components of the laboratory implementation of the computational microscope. I report the images obtained using the microscope of scattering and reflective targets. Finally, calculation of the effects of a turbulent atmosphere on the operation of the microscope are derived and demonstrated with experimental data, and a new approach to measuring the turbulent atmosphere was developed.
Plume Origins and Plumbing (Ocean to Surface)
Chapter in Enceladus and the Icy Moons of Saturn, University of Arizona (2018)
Ring and Magnetosphere Interactions with Satellite Surfaces
Chapter in Enceladus and the Icy Moons of Saturn, University of Arizona (2018)
Surface Composition of Icy Moons
Chapter in Enceladus and the Icy Moons of Saturn, University of Arizona (2018)