Space-Time Projection Optical Tomography: Search Space and Orbit Determination

In a companion article, we discussed the radiometric sensitivity and resolution of a new passive optical sensing technique, Space-Time Projection Optical Tomography (SPOT), to detect and track sub-cm and larger space debris for Space Situational Awareness. SPOT is based on the principle that long synthetic exposure can be achieved if the phase-space trajectory of a hypothetical point-source is precisely predictable within a very wide telescope field-of-view, which is the case for orbiting debris. This article discusses the computational search space for debris mining as well as a recursive measure-and-fit algorithm based on a generalized Hough transform for orbit determination.Comment: Space Situational Awarenes

Radio Aurora Explorer: A Mission Overview

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/140647/1/1.a32436.pd

Magnetic Sensor Calibration and Residual Dipole Characterization for Application to Nanosatellites

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/83632/1/AIAA-2010-7518-617.pd

Radar and rocket comparison of UHF radar scattering from auroral electrojet irregularities: Implications for a nanosatellite radar

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/95174/1/jgra19910.pd

Space-Time Projection Optical Tomography: Search Space and Orbit Determination

In a companion article, we discussed the radiometric sensitivity and resolution of a new passive optical sensing technique, Space-Time Projection Optical Tomography (SPOT), to detect and track sub-cm and larger space debris for Space Situational Awareness. SPOT is based on the principle that long synthetic exposure can be achieved if the phase-space trajectory of a hypothetical point-source is precisely predictable within a very wide telescope field-of-view, which is the case for orbiting debris. This article discusses the computational search space for debris mining as well as a recursive measure-and-fit algorithm based on a generalized Hough transform for orbit determination

Initial Flight Assessment of the Radio Aurora Explorer

We present initial flight data from the first Radio Aurora Explorer (RAX) satellite. Launched on 20 November 2011, RAX-1 was a joint venture between the University of Michigan and SRI International. Its primary mission objective was to study small-scale plasma density irregularities in the Earth’s ionosphere. Several electrostatic ion plasma instabilities are known to spawn magnetic field-aligned irregularities (FAI), or dense plasma clouds that can disrupt communication between Earth and orbiting spacecraft. The RAX mission utilized a bistatic radar configuration; the RAX spacecraft is the radar receiver and the transmitters are several world-wide incoherent scatter radars. The primary radar is located in Poker Flat, Alaska. We describe initial flight results from the mission. The radar receiver was successfully operated and performed better than estimated on orbit. RAX-1 bus performance was also successful except for the solar power generation system. A systematic fault in the panels resulted in loss of power about sixty days into the mission. Despite this failure, RAX-1 demonstrated that novel science is possible and useful on small nanosatellite platforms. We describe lessons learned from the mission. We also give a brief overview of our continued development effort on the RAX mission in preparation for a late 2011 launch of a second spacecraft, RAX-2