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Space Interferometer Mission (SIM) scheduled for launch in 2006, is one of the premiere missions in the Origins Program, NASA's endeavor to understand the origins of the galaxies, of planetary systems around distant stars, and perhaps the origins of life itself.
In this paper, we discuss artificial intelligence planning and scheduling technology and how it can be applied to interferometer configuration and control.
A multi-channel heterodyne laser interferometer is proposed for measurement of optical surface deformations at the sub-nanometer level.
A general methodology for damper placement in spaceborne interferometers is introduced.
The last 15 years has seen considerable progress in the conception and development of ideas for multi-spacecraft optical interferometers.
This paper describes the development of the wavefront tilt (pointing) control system for the JPL Micro-Precision Interferometer (MPI). This control system employs piezo-electric actuators and a digital imaging sensor with feedback compensation to reject errors in instrument pointing. Stringent performance goals require large feedback, however, several characteristics of the plant tend to restrict the available bandwidth. A robust 7th-order wavefront tilt control system was successfully implemented on the MPI instrument, providing sufficient disturbance rejection performance to satisfy the established interference fringe visibility.
Measurements were made with the Mark III stellar interferometer in order to verify predictions for the accuracy fo very-narrow-angle interferometric astrometry. The Mark III was modified to observe simultaneously on its 12-m baseline the phase of the fringe packets of the primary and secondary of the 3.3.
A multi-channel heterodyne laser interferometer is proposed for the JPL Thermo-Opto-Mechanical Testbed, which requires the measurement of optical surface deformations at the sub-nanometer level.
We present an interferometer that provides a null at the star and a direct measurement of both visibility amplitude and phase of the planets.
The Keck Interferometer is being developed by JPL and CARA as one of the ground-based components of NASA's Origins Program.
The Palomar Testbed Interferometer (PTI) has been used for several years with a 110 m baseline, at 2.2 pm observing wavelength.
Among the Keck Interferometer's high priority science programs will be the differential astrometric detection of planetary companions to nearby stars.
The Keck Interferometer Nuller (KIN) will be used to examine nearby stellar systems for the presence of circumstellar exozodiacal emission.
Now that regular visibility squared measurements are routinely achieved, mid-infrared nulling is the next observing mode to be implemented on the Keck Interferometer. This mode's main objective is the characterization of exo-zodiacal dust disks around nearby main sequence stars in support of the TPF space mission. Keck Nuller also shares numerious characteristics with an interferometric TPF, and will then serve as a technical precursor for this mission. We report here the results obtained in the laboratory with the KI mid-IR nulling beam combiner, which is based on a dual polarization Modified Mach Zender combiner and dispersion and achromatic nulling through zinc-selenide dielectric plates.
The first high dynamic range interferometry mode planned to come on line at the Keck Observatory is mid-infrared nulling interferometry. In this paper, an overview is given of the goals and experimental configuration of the Keck Interferometer Nuller (KIN).
High accuracy feedback control systems might employ tiers of actuators with different properties. Such systems performance can be estimated in advance using Bode integrals. The systems can be made globally stable with good transient responses and close to the best possible disturbance rejection when controllers include high-order linear links and multiple nonlinear dynamic links. The design approach is exemplified by designing conb-ol system for an interferometer optical delay line.
The Terrestrial Planet Finder formation flying Interferometer (TPF-I) will be a five-spacecraft, precision formation operating near the second Sun-Earth Lagrange point. As part of technology development for TPF-I, a formation and attitude control system (FACS) is being developed that achieves the precision and functionality needed for the TPF-I formation and that will be demonstrated in a distributed, real-time simulation environment. In this paper we present an overview of FACS and discuss in detail its formation estimation, guidance and control architectures and algorithms. Since FACS is currently being integrated into a high-fidelity simulation environment, component simulations demonstrating algorithm performance are presented.
We investigated the use of a simultaneous-phase acquisition interferometer (a 4D FizCamTM 1500) for determining the PSD of the extremely-high aspect ratio (500: 1) glass mirrors for the Constellation-X SXT telescope. We found that the results obtained are strongly influenced by the methodology employed while collecting the data and outline a best method for this type of measurement.