Scattered light in an externally occulted coronagraph.
Scattered light in externally occulted coronagraph
CORONAGRAPH↗
SEARCH · Search NASA
Results for “coronagraphs”
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.
Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.
Orbiting coronagraph Final report
Orbiting coronagraph feasibility study - optical design, telescope structure, and guidance and control of telescope
CORONAGRAPH↗
Use of the Moon to Distinguish the F from the K Corona Using a Rocket Coronagraph During an Eclipse
F and K corona observations by rocket coronagraph during solar eclipse
K CORONA↗
Modeling approach for the Terrestrial Planet Finder coronagraph mission
State of the art modeling for the Terrestrial Planet Finder Coronagraph mission are being developed that will combine thermal, structural, and optical modeling in one package. This tool is discussed as well as specific modeling results highlighting the capabilities of integrated modeling for TPF.
TPF Terrestrial Planet Finder coronagraph↗
Terrestrial Planet Finder coronagraph status and enabling technologies
The goal of the Terrestrial Planet Finder Project Mission is to find life-bearing planets around nearby stars. Two types of instruments are competing for flight in 2015: a visible coronagraph and an infrared interferometer.
large telescopes↗
Polarization compensating protective coatings for TPF-Coronagraph optics to control contrast degrading cross polarization leakage
We describe here the design approaches and performance analysis of the OTA in the wavelength band of interest. Coronagraph performance at 600nm wavelength based on a particular coating and occulting focal plane mask is also presented.
polarization↗
The Terrestrial Planet Finder coronagraph dynamics error budget
The Terrestrial Planet Finder Coronagraph (TPF-C) demands extreme wave front control and stability to achieve its goal of detecting earth-like planets around nearby stars. We describe the performance models and error budget used to evaluate image plane contrast and derive engineering requirements for this challenging optical system.
coronagraph↗
TPF coronagraph instrument design
For the past 2 years, NASA has invested substantial resources to study the design and performance of the Terrestrial Planet Finder Coronagraph (TPF-C). The work, led by the Jet Propulsion Laboratory with collaboration from Goddard Space Flight Center and several university and commercial entities, encompasses observatory design, performance modeling, materials characterization, primary mirror studies, and a significant technology development effort including a high-contrast imaging testbed that has achieved 1e-9 contrast in a laboratory experiment.
extra-solar planets↗
The visible nulling coronagraph -- progress towards mission and technology development
This paper describes a space mission for visible direct detection and spectroscopy of Earth like extrasolar planets using a nulling coronagraph instrument behind a moderately sized telescope in space.
coronagraph↗
Terrestrial Planet Finder Coronagraph Observatory summary
Creating an optical space telescope observatory capable of detecting and characterizing light from extra-solar terrestrial planets poses technical challenges related to extreme wavefront stability. The Terrestrial Planet Finder Coronagraph design team has been developing an observatory based on trade studies, modeling and analysis that has guided us towards design choices to enable this challenging mission. This paper will describe the current flight baseline design of the observatory and the trade studies that have been performed. The modeling and analysis of this design will be described including predicted performance and the tasks yet to be done.
space↗
Occulting focal plane masks for Terrestrial Planet Finder Coronagraph: design, fabrication, simulations and test results
Occulting focal plane masks for the Terrestrial Planet Finder Coronagraph (TPF-C) could be designed with continuous gray scale profile of the occulting pattern such as 1-sinc2 on a suitable material or with micron-scale binary transparent and opaque structures of metallic pattern on glass. We have designed, fabricated and tested both kinds of masks. The fundamental characteristics of such masks and initial test results from the High Contrast Imaging Test bed (HCIT) at JPL are presented.
adaptive optics↗
Terrestrial Planet Finder Coronagraph 2005: Overview of Technology Development and System Design Studies
Technology research, design trades, and modeling and analysis guide the definition of a Terrestrial Planet Finder Coronagraph Mission that will search for and characterize earth-like planets around near-by stars. Operating in visible wavebands, this mission will use coronagraphy techniques to suppress starlight to enable capturing and imaging the reflected light from a planet orbiting in the habitable zone of its parent star. The light will be spectrally characterized to determine the presence of life-indicating chemistry in the planet atmosphere.
coronagraph↗
Terrestrial Planet Finder Coronagraph and Enabling Technologies
Starlight suppression research is Stowed in Delta IV-H advancing rapidly to approach the required contrast ratio. The current analysis of the TPF Coronagraph system indicates that it is feasible to achieve the stability required by using developing technologies: a) Wave Front Sensing and Control (DMs, control algorithms, and sensing); b) Laser metrology. Yet needed: a) Property data measured with great precision in the required environments; b) Modeling tools that are verified with testbeds.
Terrestrial Planet Finder↗
Design and Performance of the Terrestrial Planet Finder Coronagraph
Terrestrial Planet Finder Coronagraph, one of two potential architectures, is described. The telescope is designed to make a visible wavelength survey of the habitable zones of at least thirty stars in search of earth-like planets. The preliminary system requirements, optical parameters, mechanical and thermal design, operations scenario and predicted performance is presented. The 6-meter aperture telescope has a monolithic primary mirror, which along with the secondary tower, are being designed to meet the stringent optical tolerances of the planet-finding mission. Performance predictions include dynamic and thermal finite element analysis of the telescope optics and structure, which are used to make predictions of the optical performance of the system.
designs↗
The Terrestrial Planet Finder Coronagraph Optical Surface Requirements
Coronagraph telescope and instrument optics for spatial frequencies within and beyond the spatial control bandwidth of the wave front control system. Three different wave front control systems are considered: a zero-path difference Michelson interferometer with two deformable mirrors at a pupil image; a sequential pair of deformable mirrors with one placed at a pupil image; and the Visible Nuller spatially-filtered controller. We show that the optical bandwidth limits the useful outer working angle.
telescope requirements↗
Fabrication and Characteristics of Free Standing Shaped Pupil Masks for TPF-Coronagraph
Direct imaging and characterization of exo-solar terrestrial planets require coronagraphic instruments capable of suppressing star light to 10-10. Pupil shaping masks have been proposed and designed1 at Princeton University to accomplish such a goal. Based on Princeton designs, free standing (without a substrate) silicon masks have been fabricated with lithographic and deep etching techniques. In this paper, we discuss the fabrication of such masks and present their physical and optical characteristics in relevance to their performance over the visible to near IR bandwidth.
terrestrial planet finder↗
Effects of Optical-density and Phase Dispersion of an Imperfect Band-limited Occulting Mask on the Broadband Performance of a TPF Coronagraph
Practical image-plane occulting masks required by high-contrast imaging systems such as the TPF-Coronagraph introduce phase errors into the transmitting beam., or, equivalently, diffracts the residual starlight into the area of the final image plane used for detecting exo-planets. Our group at JPL has recently proposed spatially Profiled metal masks that can be designed to have zero parasitic phase at the center wavelength of the incoming broadband light with small amounts of' 00 and phase dispersions at other wavelengths. Work is currently underway to design. fabricate and characterize such image-plane masks. In order to gain some understanding on the behaviors of these new imperfect band-limited occulting masks and clarify how such masks utilizing different metals or alloys compare with each other, we carried out some modeling and simulations on the contrast performance of the high-contrast imaging testbed (HCIT) at .JPL. In this paper we describe the details of our simulations and present our results.
integrated modeling↗
The Visible Nulling Coronagraph--Architecture Definition and Technology Development
This paper describes the advantages of visible direct detection and spectroscopy of Earth-like extrasolar planets using a nulling coronagraph instrument behind a moderately sized single aperture space telescope. Our concept synthesizes a nulling interferometer by shearing the telescope pupil, with the resultant producing a deep null. We describe nulling configurations that also include methods to mitigate stellar leakage, such as spatial filtering by a coherent array of single mode fibers, and post-starlight suppression wavefront sensing and control. With diffraction limited telescope optics and similar quality components in the optical train (lambda/20), suppression of the starlight to 1e-10 is readily achievable. We describe key features of the architecture and analysis, present latest results of laboratory measurements demonstrating achievable null depth and component development, and discuss future key technical milestones.
nulling interferometer↗