A multidisciplinary analysis is demonstrated for the NEXUS space telescope precursor mission. This mission was originally designed as an in-space technology testbed for the Next Generation Space Telescope (NGST). One of the main challenges is to achieve a very tight pointing accuracy with a sub-pixel line-of-sight (LOS) jitter budget and a root-mean-square (RMS) wavefront error smaller than =50...

Recently some pessimism has been expressed about our lack of progress in understanding quasars over the 50+ year since their discovery (Antonucci, 2013). It is worthwhile to look back at some of the progress that has been made—but still lies under the radar—perhaps because few people are working on optical/UV spectroscopy in this field. Great advances in understanding quasar phenomenology have ...

We have analyzed the behavior of a multiple element antenna system in an indoor environment based on the measurements taken in the Lucent Crawford Hill building with a system of 12 transmitters and 15 receivers. The parameters that we investigated were the distance between the transmitting and the receiving arrays, and the polarization of the transmitter/ receiver elements. Our measurements sho...

The classical concept of extrapolating the photospheric magnetic field from line-of-sight measurements B` assuming a pure force-free field is revisited and a new procedure is proposed which is based on: 1) non-vanishing magnetic forces, 2) known horizontal forces from direct measurement of pressure or a related quantity (continuum brightness), 3) a small perturbation to the potential or linear ...

Multiple-input–multiple-output (MIMO) systems have the potential to achieve very high capacities, depending on the propagation environment. Capacity increases as signal correlation decreases. We present the measurements of a MIMO system under strong and weak line-of-sight conditions. The system capacity decreases as the distance from the transmitter increases. Indeed the transmitter correlation...

Channel modelling and performance of non-line-of-sight ultraviolet scattering communications Report Title The solar blind ultraviolet (UV) spectrum shows unique properties for wireless communication and sensing. Sufficient scattering in UV spectrum can make a non-line-of-sight (NLOS) communication scenario feasible. We present recent experimental and analytical results in non-line-of-sight UV c...

Abstract-A MIMO channel measurement campaign with a moving mobile has been conducted in Vienna. The measured data will be used to investigate covariance matrices with respect to their dependence on time and frequency. This document focuses on the description of the evaluation techniques which will be applied to the measurement data in the future. The F-eigen-ratio is defined expressing the degr...

International Journal of Systems Science Publication details, including instructions for authors and subscription information: http://www.informaworld.com/smpp/title~content=t713697751 Real-time neural-network-based control of a gyro-mirror line-of-sight stabilization platform T. H. Lee a; S. S. Ge a; C. C. Hang a; Q. Zhao a; A. S. Au a a Department of Electrical Engineering, National Universit...

In this paper we propose a new shadowed Rice model for land mobile satellite channels. In this model the amplitude of the line-of-sight is characterized by the Nakagami distribution. The model provides closed-form mathematically-tractable expressions for the fundamental channel statistics such as envelope probability density function and envelope-squared moment generating function. The model is...