A balloon-borne Michelson interferometer for solar spectroscopy in the 10-100 micron region.
Balloon-borne Michelson interferometer for far IR solar spectrometry
INFRARED SPECTRUM↗
SEARCH · Engineering Papers
Results for “INTERFEROMETER”
Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.
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SIM: An end-to-end simulation of the Space Interferometer Mission
We present the basic elements and first results of an end-to-end simulation package whose purpose is to test the validity of the Space Interferometer Mission design. The fundamental simulation time step is one millisecond, with substructure at 118 ms, and the total duration of the simulation is five years. The end product of a given wide-angle astrometry run is an estimated grid star catalog over the entire sky with an accuracy of about 4 micro-arcseconds.
SIM Space Interferometer Mission Space telescopes ↗
Overview of the control for the Keck Interferometer
This paper gives an overview of the control system that has been implemented for the single baseline operation of the Keck Interferometer and indicates how this will be extended to allow control of the future modes of the instrument.
Keck Interferometer interferometry real time contr↗
Optical alignment of the TES cryogenic interferometer
This paper describes the methodology used to align the interferometer optics in the TES cryogenic Fourier Transform Spectrometer.
alignment interferometer↗
Detecting extrasolar planets with the Keck Interferometer
We discuss the development of the Differential Phase detection technique for the Keck Interferometer Hot Jupiter Key Science Program.
infrared interferometer↗
Detection of extrasolar planets with the Keck Interferometer
We discuss the development of the Differential Phase detection technique for the Keck Interferometer Hot Jupiter Key Science Program.
extrasolar planets Keck interferometer Hot Jupiter↗
Spacecraft to Spacecraft Coherent Laser Tracking as a Xylophone Interferometer Detector of Gravitational Radiation
Searches for gravitational radiation can be performed in space with two spacecraft tracking each other with coherent laser light. This experimental technique could be implemented with two spacecraft carrying an appropriate optical payload, or with the proposed broad-band, space-based laser interferometer detectors of gravitational waves operated in this non-interferometric mode.
interferometer↗
POINTS (Precision Optical INTerferometer in Space)
POINTS is a high-precision, high-throughput interferometer intended for astromomy only. It can perform science compatable with astrophysics (AIM) and planet detection (TOPS-1). The spacecraft will be compact, lightweight, and suitable for high Earth orbit. It will employ the minimal number and complexity of mechanisms or deployable parts and be designed for a 10 year mission life.
interferometer astronomy satellite↗
Cancellation of Laser Noise in an Unequal-arm Interferometer Detector of Gravitational Radiation
In this paper we present a method for exactly cancelling the laser noise in a one-bounce unequal-arm Michelson interferometer. The method requries separate measurements of the phase difference in each arm, made by interfering the returning laser light in each arm with the outgoing light.
gravitational radiation laser noise unequal-arm Mi↗
Final laboratory integration and test of the Keck Interferometer nuller
Mid-infrared nulling is a key observing mode planned for the NASA-funded Keck Interferometer at the Keck Observatory on the summit of Mauna Kea in Hawaii.
extrasolar planet detection↗
Visibility science operations with the Keck Interferometer
The visibility science mode of the Keck Interferometer fully transitioned into operations with the successful completion of its operational readiness review in April, 2004. The goal of this paper is to describe this science mode and the operations structure that supports it.
interferometer↗
Keck Interferometer autoaligner : algorithms and techniques
The Keck Interferometer includes an autoalignment system consisting of pop-up targets located at strategic locations along the beam trains of each arm of the instrument along with a sensor and control system. We briefly describe the hardware of the system and then proceed to a description of the two operational modes of the system.
Interferometry↗
Remote sensing of sea ice thickness by a combined spatial and frequency domain interferometer : formulations, instrument design & development
The thickness of Arctic sea ice plays a critical role in Earth's climate and ocean circulation. An accurate measurement of this parameter on synoptic scales at regular intervals would enable characterization of this important component for the understanding of ocean circulation and the global heat balance. Presented in this paper is a low frequency VHF interferometer technique and associated radar instrument design to measure sea ice thickness based on the use of backscatter correlation functions. The sea ice medium is represented as a multi-layered medium consisting of snow, seaice and sea water, with the interfaces between layers characterized as rough surfaces. This technique utilizes the correlation of two radar waves of different frequencies and incident and observation angles, scattered from the sea ice medium. The correlation functions relate information about the sea ice thickness. Inversion techniques such as the genetic algorithm, gradient descent, and least square methods, are used to derive sea ice thickness from the phase information related by the correlation functions.
remote sensing↗
Sub-nanometer Level Model Validation of the SIM Interferometer
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 obtained from the MicroArcsecond Metrology (MAM) testbed adn the Diffraction testbed (DTB). The metric for validation is provided by the SIM astrometric error budget.
modeling↗
Adaptive Nulling for the Terrestrial Planet Finder Interferometer
A description of adaptive nulling for Terrestrial Planet Finder Interferometer (TPFI) is presented. The topics include: 1) Nulling in TPF-I; 2) Why Do Adaptive Nulling; 3) Parallel High-Order Compensator Design; 4) Phase and Amplitude Control; 5) Development Activates; 6) Requirements; 7) Simplified Experimental Setup; 8) Intensity Correction; and 9) Intensity Dispersion Stability. A short summary is also given on adaptive nulling for the TPFI.
adaptive nulling↗
Spectrally Resolved Synthetic Aperture Imaging Interferometer: Final Report of NASA Innovative Advanced Concepts - Phase 1 Study
The Spectrally Resolved Synthetic-Aperture Imaging Interferometer (SRSAII) is a system proposed to provide high-resolution and high-sensitivity measurements of astronomical objects. SRSAII uses long baseline interferometric methods to achieve the resolution and low-noise, high time-precision detection to achieve the sensitivity. The primary goal of the SRSAII study was to lay out a framework for using new optical physics technologies to directly resolve, both spatially and spectrally, the disk of an exoplanet. In addition to the ambitious goal of directly resolving an exoplanet, the SRSAII team also sought to identify science opportunities achievable with intermediate system configurations which may offer resolution significantly higher than the current state of the art, but insufficient for direct resolution of an exoplanetary disk. An operational SRSAII system can function with essentially arbitrarily large baselines, achieving correspondingly high angular resolution. The primary limitation occurs in the system sensitivity, which became the major technical focus for study. In this report, we compare the predicted performance (sensitivity in SNR (Signal-to-Noise Ratio) along with angular resolution) of three interferometric techniques: direct detection (also known as homodyne interferometry), multi-channel intensity interferometry (using the Hanbury Brown and Twiss effect), and multi-channel heterodyne interferometry (using an optical frequency comb as a local oscillator). Additionally, quantum-assisted interferometry is also explored as a prospective enhancement of established methods. This report presents a survey of the technologies that enable the SRSAII techniques - optical frequency combs, single photon detectors, and photonic integrated circuits. These technologies are the basis of methods critical to SRSAII's success: precision timing, length and frequency metrology, sensitive photodetection, fine-scale wavelength filtering, and dense multi-channel operation. Lastly, we give some notional performance metrics and propose some possible experimental observations.
High Resolultion↗
Analysis of the Amplitude Response of a Two-Point and a Two-Line/Multi-Point Focused Laser Differential Interferometer
Experiments were performed with two different focused laser differential interferometer (FLDI) instruments to assess the amplitude response of each instrument to a traveling shock-wave generated by a laser spark. The first FLDI instrument generated two measurement points, with each measurement point providing sensitivity to density fluctuations induced by the shockwave. By performing a cross-correlation between the signals obtained from each measurement point, the phase velocity of density fluctuations can be obtained. The second FLDI instrument generated two measurement lines that are oriented either parallel or orthogonal to the shockwave direction of travel with the resulting interference pattern sampled at multiple equally-spaced points along each line. As a result, this instrument provides density fluctuation measurement capability at multiple points simultaneously. When the measurement lines are oriented parallel to the shockwave direction of travel, the phase velocity, rate of change of the phase velocity, and acceleration of density fluctuations traveling along each line can be obtained by performing a cross-correlation between points along a single line. When the measurement lines are oriented orthogonal to the shockwave direction of travel, the spatially-varying phase velocity can be obtained by performing a cross-correlation between points at the same relative location on each measurement line. Computations of the shockwave generated by the laser spark are used to simulate the response of each instrument and are compared to the experimental results. High-speed Schlieren imaging has also been performed and is compared with the FLDI measurements and computational results.
Focused Laser Differential Interferometer↗
Antarctic Planet Interferometer
The Antarctic Planet Interferometer (API) is a concept designed to detect and characterize extrasolar planets by exploiting the unique potential of the best accessible site on Earth for thermal infrared interferometry.
interferometer↗