Study of a navigation and traffic control technique employing satellites. Volume 5 - Addendum. Traffic control data links Final report

Data links for air traffic control capability by satellites of NAVSTAR syste

Navigation/traffic control satellite mission study. Volume 3 - System concepts

Satellite network for air traffic control, solar flare warning, and collision avoidanc

The First Multichroic Receiver and Results from ACTPol.

The Cosmic Microwave Background (CMB) is a unique and powerful tool for the study of cosmology and fundamental physics. The next frontier of CMB research is to extract the wealth of cosmological information available from its polarization. Accurate measurement of this polarization signal will enable us to probe inflation, provide an alternative means to measure the neutrino mass sum and number of neutrino species; improve our understanding of dark energy; explore the reionization history of our Universe; probe the large scale structure through gravitational lensing; and enable a multitude of other astrophysical studies. The polarized signatures of the early universe are extremely weak, dominated by foregrounds, and its measurement is susceptible to instrumental effects. Extracting the information contained in these faint signals requires instruments with high sensitivity, excellent control over systematic errors, and careful data analysis. The Atacama Cosmology Telescope Polarimeter (ACTPol) is a state-of-the-art experiment that measures CMB polarization over finer angular scales from the Atacama desert in Chile. In this thesis, I present an overview of this project and then describe my work on the project including development of a new polarization sensitive dichroic camera for ACTPol designed to increase the sensitivity of CMB telescopes and enable high precision measurements of CMB polarization; the development of novel metamaterial antireflection coatings for silicon lenses; diffraction from panel gaps; calibration of detector pass-bands; and a detailed description of my analysis of the polarization properties of extragalactic point sources discovered with the ACTPol data. I conclude with a discussion of the science of ACTPol, and the impact of my technical work on future CMB experiments.PHDPhysicsUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/135767/1/dattar_1.pd

Single and Multiple-Band Bandpass Filters Using Bandstop Resonator Sections

In this paper, the design methodology and implementation of single-band and multiple-band elliptic function bandpass filters (BPFs) are presented, based on the concept of bandstop resonator (BSR) sections. One or more single-mode and multiple-mode BSRs can be dangled from a non-resonant node. Each BSR can generate one reflection zeroes (RZ) and one transmission zeroes (TZ). Multiple BSR sections are used to flexibly and independently control the location and bandwidth of the stop bands and therefore the same of the passbands. The method to design single- and multiple-band elliptic function BPFs has been detailed using a number of examples based on waveguide technology. For proof of concept, a 6th-order single-band BPF with six BSR&amp;#x00A0;&amp;#x003D;&amp;#x00A0;2 sections and a 3rd-order dual-band BPF using three BSR&amp;#x00A0;&amp;#x003D;&amp;#x00A0;3 sections are designed and fabricated monolithically using a selective-laser-melting (SLM) 3-D printing technique. Excellent agreement between simulated and measured results verifies the proposed design methodology and its versatility as well as the additive-manufacture approach.</p

A Quasi-Optical Astronomical Receiver.

PhDThis thesis describes the work undertaken in producing the passive radio-frequency section of a heterodyne receiver for use on the United Kingdom Infra-Red Telescope at signal frequencies in the 200-300 GHz range. This is a Quasi-Optical system, comprised of a Martin-Puplet polarising interferometer employed as a diplexer and the lenses and feed horns by which the diplexer was coupled to the telescope, local oscillator, and mixer. The Gaussian beam-mode approach was employed to develop a theoretical basis for understanding the operation of such a system upon coherent paraxial beams. Quasi-Optical systems were then designed and their performance predicted by the application of this extension of Gaussian optics. Two such systems were constructed and their performance determined by laboratory measurements to be as predicted. One of these systems was then installed on the telescope where it was shown to function as designed. As part of the calibration and test routine on the telescope a number of astronomical measurements were made, including a determination of the apparent temperatures of the planets Jupiter and Saturn by a method different to that employed for results previously published. The Quasi-Optical receiver was successfully calibrated and commissioned as a common-user instrument. As such it will continue to be used in a variety of astronomical research programs undertaken by various groups.Science Research Counci

Advanced Syncom - Syncom II summary report

Spacecraft systems design, reliability, support equipment, alternate configurations, and radiation instrumentation payload for Syncom I

Design/cost tradeoff studies. Appendix A. Supporting analyses and tradeoffs, book 1. Earth Observatory Satellite system definition study (EOS)

A listing of the Earth Observatory Satellite (EOS) candidate missions is presented for use as a baseline in describing the EOS payloads. The missions are identified in terms of first, second, and third generation payloads. The specific applications of the EOS satellites are defined. The subjects considered are: (1) orbit analysis, (2) space shuttle interfaces, (3) thematic mapping subsystem, (4) high resolution pointable imager subsystem, (5) the data collection system, (6) the synthetic aperture radar, (7) the passive multichannel microwave radiometer, and (8) the wideband communications and handling equipment. Illustrations of the satellite and launch vehicle configurations are provided. Block diagrams of the electronic circuits are included

Observations of Upper Mesosphere Temperatures on Venus and Evaluation of Mid-Infrared Detectors for the Tuneable Infrared Heterodyne Spectrometer (THIS)

Infrared heterodyne spectroscopy today is an inherent part in planetary atmosphere observations. It is based on the superposition of the observed signal to a local oscillator and provides highest possible spectral resolution. Non-thermal emission of CO2 in the upper mesosphere of Venus was discovered by the NASA Infrared Heterodyne Spectrometer (IRHS) in the 1970s and was repeatedly target of observations since then. In the course of this thesis, data of with IRHS, its successor HIPWAC and the Cologne Tuneable Heterodyne Infrared Spectrometer (THIS) was taken or analysed. From the measured line widths the kinetic temperature of the atmosphere at the emission altitude of around 115 km could be determined. Observed temperatures are generally higher than predicted by the Venus International Reference Atmosphere (VIRA). VIRA is a empirical model mainly based on data of the Pioneer Venus space mission and exhibits only a limited data set. Other ground-based observations as well as results from Venus Express confirm the warm atmosphere at similar altitudes. At the day side of Venus and at this specific altitude, infrared heterodyne spectroscopy is currently the only method to observe temperatures. Another result is the high variability of the observed atmosphere which is not expected by the VIRA model but which was also seen in earlier mm-wavelength observations. The obtained results also set new constraints for modern global circulation models. Improving those models will lead to a improved knowledge of planetary atmospheres. As all those models are based on the Earth atmosphere model, our observations might subsequently lead to a better understanding of the terrestrial climate as well. The second part of this thesis deals with the evaluation of possible detectors for THIS to expand the wavelength coverage to longer wavelengths. Many atomic and molecular lines could be targeted within the solar system and beyond. The main target will be cold molecular hydrogen in the interstellar medium which is of highest importance in astrophysical questions concerning star forming, dark matter and cosmology. For this reason first tests at 17 micrometer wavelength were done in the course of this work