Showing papers by "Daniel J. Hoppe published in 2004"
01 May 2004
TL;DR: The design and development of the low cost 6-meter breadboard antenna is described to be used as part of the interferometer to prove the performance and cost of a very large DSN array.
Abstract: Development of very large arrays of small antennas has been proposed as a way to increase the downlink capability of the NASA deep space network (DSN) by two or three orders of magnitude thereby enabling greatly increased science data from currently configured missions or enabling new mission concepts. The current concept is for an array of 400/spl times/12-m antennas at each of the three longitudes. The DSN array utilizes radio astronomy sources for phase calibration and has wide bandwidth correlation processing for this purpose. A program is currently underway to develop the technology and prove the performance and cost of a very large DSN array. The program includes a 3-element interferometer to be completed by late 2004. This paper describes the design and development of the low cost 6-meter breadboard antenna to be used as part of the interferometer.
8 citations
TL;DR: In this paper, a set of models that are used to predict the magnitude and functional form of a class of field-dependent systematic errors for the science and guide interferometers is presented.
Abstract: The Space Interferometer Mission (SIM) flight instrument will not undergo a full performance, end-to-end system test on the ground due to a number of constraints. Thus, analysis and physics-based models will play a significant role in providing confidence that SIM will meet its science goals on orbit. The various models themselves are validated against the experimental results of severl "picometer" testbeds. In this paper we describe a set of models that are used to predict the magnitude and functional form of a class of field-dependent systematic errors for the science and guide interferometers. This set of models is validated by comparing predictions with the experimental results obtained from the MicroArcsecond Metrology (MAM) testbed and the Diffraction testbed (DTB). The metric for validation is provided by the SIM astrometric error budget.
7 citations
06 Mar 2004
TL;DR: In this article, the authors describe the design and development of a low-cost 6-meter breadboard antenna to be used as part of the interferometer and demonstrate the performance and cost of a very large DSN array.
Abstract: Development of very large arrays of small antennas has been proposed as a way to increase the downlink capability of the NASA deep space network (DSN) by two or three orders of magnitude thereby enabling greatly increased science data from currently configured missions or enabling new mission concepts The current concept is for an array of 400/spl times/12-m antennas at each of the three longitudes The DSN array utilizes radio astronomy sources for phase calibration and has wide bandwidth correlation processing for this purpose A program is currently underway to develop the technology and prove the performance and cost of a very large DSN array The program includes a 3-element interferometer to be completed by late 2004 This paper describes the design and development of the low cost 6-meter breadboard antenna to be used as part of the interferometer
3 citations
30 Jan 2004
TL;DR: An analytical description of the scattered light from a 10 meter diameter Diffractive Optical Element lens-based telescope operating at 1 micron wavelength has been formulated in this article, where the specifics of the grating and blaze as well as physical manufacturing constraints were made a part of the problem to be solved.
Abstract: An analytical description of the scattered light from a 10 meter diameter Diffractive Optical Element lens-based telescope operating at 1 micron wavelength has been formulated. The specifics of the grating and blaze as well as physical manufacturing constraints were made a part of the problem to be solved. A major simplifying approximation made is that a 1 dimensional lens was assumed for the calculations. This simplified model still serves to illustrate the important effects and limitations of a high performance lens used as a telescope. Focal plane light scattering has been rigorously determined for simplified cases.
1 citations
07 Sep 2004
TL;DR: In this article, a NASA mission was proposed to find and characterize terrestrial exo-planets that might harbor life (like Earth) liquid water on the planet (habitable zone) and an atmosphere that indicates the presence of life water, oxygen, ozone, carbon dioxide, chlorophyll, and methane.
Abstract: Astronomers have discovered over 150 planets orbiting other stars. NASA mission; Find and characterize terrestrial (or rocky) exo-planets that might harbor life (like Earth)liquid water on the planet (habitable zone). An atmosphere that indicates the presence of life water, oxygen, ozone, carbon dioxide, chlorophyll, and methane. Two missions under development: A coronagraph and an interferometer.
1 citations