Clement Lee

Lunar topographic mapping using a new high resolution mode for the GSSR radar

Mapping the Moons topography using Earth based radar interferometric measurements by the Goldstone Solar System Radar (GSSR) has been done several times since the mid 1990s. In 2008 we reported at this conference the generation of lunar topographic maps having approximately 4 m height accuracy at a horizontal posting of 40 m. Since then GSSR radar has been improved to allow 40 MHz bandwidth imaging and consequently obtained images and interferograms with a resolution of about 4 m in range by 5 m in azimuth. The long synthetic aperture times of approximately 90 minutes in duration necessitated a migration from range/Doppler image formation techniques to spotlight mode processing and autofocusing methods. The improved resolution imagery should permit the generation of topographic maps with a factor of two better spatial resolution with about same height accuracy. Coupled the with the recent availability of new lidar topography maps of the lunar surface made by orbiting satellites of Japan and the United States the geodetic control of the radar generated maps products can be improved dramatically. This paper will discuss the hardware and software improvements made to the GSSR and present some of the new high resolution products.

Photon counting techniques for the bandlimited optical channel

Two methods of estimating received photon counts given a realistic noisy and bandlimited optical channel are presented. The function of estimating photon counts is critical in any optical communications receiver. The purpose of this work is to compare two methods - neither of which is generically optimal with realistic channels - for the purpose of assessing which is more appropriate for application in a hardware receiver given the current state-of-the art

Space-based autonomous reconfigurable protocol chip

In this paper, we present an architecture for a reconfigurable protocol chip for space-based applications. We present a model for examining various stimuli for reconfiguration in space, and identify some approaches to operating on the stimuli. In particular, we examine fault tolerant schemes and reconfiguration based on detection of a link layer framing format