Proposal Number: 0841334 Proposal Title: SGER: Adaptive Intelligent Interferometric Imaging System PI Name: Suman Chakravorty PI Institution: Texas A&M University - Texas Engineering Experiment Station
Objective: The PI will develop new technology to improve our ability (and reduce the cost) to perform high resolution imaging of distant astronomical targets such as exo-solar systems and protoplanetary disks. These high resolution imaging tasks will be addressed by using multi-spacecraft interferometric imaging systems (MSIIS). Such systems synthesize a large optical aperture by interfering the light collected by smaller aperture telescopes carried by the component spacecraft of such systems. The state of the art for the maneuver design of such systems attempts to uniformly fill the Fourier/u-v plane of the image. However, such maneuvers lead to an exceedingly wasteful expenditure of resources since the Fourier plane of any image is quite sparse. The new methodology proposed here is intended to reduce that waste, and thereby substantially reduce the cost of achieving ambitious goals in astronomical imaging.
Intellectual merit of proposal: The intelligent imagining methodology is formulated as a stochastic adaptive control problem. It consists of: (a) intensity correlation interferometry based on the Hanbury-Brown-Twiss (HB-T) quantum optic effect; (b) forming a constant probabilistic estimate of the image using noisy interferometric measurements made by the component spacecraft; and (c) utilizing this probablilistic estimate of the image to guide the motion of the component spacecraft such that most of the resources of the system are utilized in exploring the "information rich" areas of the u-v plane. Intensity correlation interferometry (ICI) based on the HB-T effect results in relaxation of the precision control requirements by several orders of magnitude. The image estimation problem will be addressed by a new methodology grounded in frequentist statistics. The motion planning of the spacecraft is proposed to be solved using approximate dynamic programming (ADP) utilizing the probabilistic estimates of the image content from the estimation algorithm.
Broad impact of proposal: This new technology should permit the development of high resolution imaging systems with effective aperture sizes that are heretofore unheard of. For example, it may make it far more feasible and affordable for us to detect the spectral signature of plant life in earth-sized planets within 100 to 100 light years of earth. The recruitment of graduate, undergraduate and high school students to participate in the research performed at the ground-based observatory in TAMU as part of this project will literally opn new worlds for these students. Among these students will be underrepresented minority students who will be actively recruited from Bryan High School (BHS).
