Raytheon

About: Raytheon is a company organization based out in Waltham, Massachusetts, United States. It is known for research contribution in the topics: Signal & Antenna (radio). The organization has 15290 authors who have published 18973 publications receiving 300052 citations.

Feasibility Study of a Satellite Solar Power Station

Abstract: A feasibility study of a satellite solar power station (SSPS) was conducted to: (1) explore how an SSPS could be flown and controlled in orbit; (2) determine the techniques needed to avoid radio frequency interference (RFI); and (3) determine the key environmental, technological, and economic issues involved Structural and dynamic analyses of the SSPS structure were performed, and deflections and internal member loads were determined Desirable material characteristics were assessed and technology developments identified Flight control performance of the SSPS baseline design was evaluated and parametric sizing studies were performed The study of RFI avoidance techniques covered (1) optimization of the microwave transmission system; (2) device design and expected RFI; and (3) SSPS RFI effects The identification of key issues involved (1) microwave generation, transmissions, and rectification and solar energy conversion; (2) environmental-ecological impact and biological effects; and (3) economic issues, ie, costs and benefits associated with the SSPS The feasibility of the SSPS based on the parameters of the study was established

Mixed technology mems/sige bicmos digitizing analog front end with direct rf sampling

Abstract: A digitizing analog front end (DAFE) (50) using mixed technology on a single substrate is described. SiGe BiCMOS technology is implemented for the semiconductor components, which include a low noise amplifier (64) and an analog-to-digital converter (68). Micro Electro Mechanical System (MEMS) switches are used to change the filtering characteristics of several filters, including an anti-aliasing filter (66) and a pre-select and anti-jamming filter (62).

On-orbit performance of the Far Ultraviolet Spectroscopic Explorer (FUSE)

Abstract: The Far Ultraviolet Spectroscopic Explorer (FUSE) satellite was launched into orbit on June 24, 1999. FUSE is now making high resolution ((lambda) /(Delta) (lambda) equals 20,000 - 25,000) observations of solar system, galactic, and extragalactic targets in the far ultraviolet wavelength region (905 - 1187 angstroms). Its high effective area, low background, and planned three year life allow observations of objects which have been too faint for previous high resolution instruments in this wavelength range. In this paper, we describe the on- orbit performance of the FUSE satellite during its first nine months of operation, including measurements of sensitivity and resolution.© (2000) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

Directed infrared countermeasures (DIRCM) system and method

Abstract: An agile, high-power, reliable DIRCM system that is easily extended to address sophisticated UV or UV-visible capable multi-band threats includes a missile warner having missile warning receivers (MWRs), one or two-color suitably in the mid-IR range, that detect likely missile launch and pass the threat coordinates to a pointer-tracker having a Roll/Nod gimbal on which the IR laser transmitter is mounted. The pointer-tracker slews the gimbal to initiate tracking based on the threat coordinates and then uses its detector to continue to track and verify the threat. If the threat is verified, the pointer-tracker engages the laser to fire and jam the missile's IR seeker. By slewing the gimbal based on unverified threat coordinates to initiate tracking the system is highly agile and can respond to short and near simultaneous MANPADS shots.

Angular Distributions of Solar Energetic Particles

Abstract: We report observations, using data from the Wind spacecraft, of temporal variations in the angular distributions of H, He, O, and Fe ions at MeV energies during solar energetic particle (SEP) events under a variety of conditions. Detailed time-dependent angular distributions of O and Fe during SEP events are reported for the first time. Extended periods of particle streaming in small gradual events are consistent with continued acceleration that is expected at shock waves driven from the Sun by coronal mass ejections (CMEs). Particles accelerated from SEP events of moderate size show especially strong streaming along the magnetic fields inside an old CME. For the largest events, however, streaming rapidly diminishes, showing behavior that is qualitatively consistent with the theory of Ng et al. In very intense events, that theory predicts rapid growth of proton-generated Alfven waves, even near and beyond 1 AU, that soon scatter and isotropize the particles. We show, for the first time, cases where SEP streaming is organized by the value of the plasma beta βp, the ratio of the proton thermal energy to magnetic energy. Higher initial turbulence in the high-βp plasma may require less additional wave growth to reach significant levels of scattering in the largest SEP events.