scholarly journals Comparison of wavefront control algorithms and first results on the high-contrast imager for complex aperture telescopes (hicat) testbed

Author(s):  
L. Leboulleux ◽  
S. Egron ◽  
M. N'Diaye ◽  
J. Mazoyer ◽  
L. Pueyo ◽  
...  
2003 ◽  
Author(s):  
Scott A. Basinger ◽  
Joseph J. Green ◽  
Stuart B. Shaklan ◽  
David C. Redding

Author(s):  
Jorge Llop Sayson ◽  
Garreth Ruane ◽  
Nemanja Jovanovic ◽  
Dimitri Mawet ◽  
Daniel Echeverri ◽  
...  

2018 ◽  
Vol 14 (S345) ◽  
pp. 316-317 ◽  
Author(s):  
M. Mugrauer ◽  
C. Ginski ◽  
N. Vogt ◽  
R. Neuhäuser ◽  
C. Adam

AbstractIn order to determine the true impact of stellar multiplicity on the formation and evolution of planets, we initiated direct imaging surveys to search for (sub)stellar companions of exoplanet host stars on close orbits, as their gravitational impact on the planet bearing disk at first and on formed planets afterwards is expected to be maximal. According to theory these are the most challenging environments for planet formation and evolution but might occur quite frequently in the milky way, due to the large number of multiple stars within our galaxy. On this poster we showed results, obtained so far in the course of our AO and Lucky-imaging campaigns of exoplanet host stars, conducted with NACO/ESO-VLT for southern and with AstraLux/CAHA2.2m for northern targets, respectively. In addition, we introduced our new high contrast imaging survey with SPHERE/ESO-VLT to search for close companions of southern exoplanet host stars, and presented some first results.


Micromachines ◽  
2019 ◽  
Vol 10 (6) ◽  
pp. 366 ◽  
Author(s):  
Rachel E. Morgan ◽  
Ewan S. Douglas ◽  
Gregory W. Allan ◽  
Paul Bierden ◽  
Supriya Chakrabarti ◽  
...  

Micro-Electro-Mechanical Systems (MEMS) Deformable Mirrors (DMs) enable precise wavefront control for optical systems. This technology can be used to meet the extreme wavefront control requirements for high contrast imaging of exoplanets with coronagraph instruments. MEMS DM technology is being demonstrated and developed in preparation for future exoplanet high contrast imaging space telescopes, including the Wide Field Infrared Survey Telescope (WFIRST) mission which supported the development of a 2040 actuator MEMS DM. In this paper, we discuss ground testing results and several projects which demonstrate the operation of MEMS DMs in the space environment. The missions include the Planet Imaging Concept Testbed Using a Recoverable Experiment (PICTURE) sounding rocket (launched 2011), the Planet Imaging Coronagraphic Technology Using a Reconfigurable Experimental Base (PICTURE-B) sounding rocket (launched 2015), the Planetary Imaging Concept Testbed Using a Recoverable Experiment - Coronagraph (PICTURE-C) high altitude balloon (expected launch 2019), the High Contrast Imaging Balloon System (HiCIBaS) high altitude balloon (launched 2018), and the Deformable Mirror Demonstration Mission (DeMi) CubeSat mission (expected launch late 2019). We summarize results from the previously flown missions and objectives for the missions that are next on the pad. PICTURE had technical difficulties with the sounding rocket telemetry system. PICTURE-B demonstrated functionality at >100 km altitude after the payload experienced 12-g RMS (Vehicle Level 2) test and sounding rocket launch loads. The PICTURE-C balloon aims to demonstrate 10 - 7 contrast using a vector vortex coronagraph, image plane wavefront sensor, and a 952 actuator MEMS DM. The HiClBaS flight experienced a DM cabling issue, but the 37-segment hexagonal piston-tip-tilt DM is operational post-flight. The DeMi mission aims to demonstrate wavefront control to a precision of less than 100 nm RMS in space with a 140 actuator MEMS DM.


2017 ◽  
Vol 59 (1) ◽  
Author(s):  
David Steber

AbstractThe further integration of storage into the electric power system is unavoidable regarding the still increasing share of renewables and current market developments. Therefore a lot of different storage technologies are available today. The presented PhD-Thesis project will focus on integrating battery storage to the power system under different system and market conditions. Therefore, coupled control algorithms for single and virtual battery storage systems have to be developed depending on the battery's scope. For analyzing the reliability of different battery's scopes, the developed models will be integrated into an electric power system model for studying their influence on the power system and market concerning different development scenarios (renewables, nuclear phase-out). First actions dealt with the provision of Frequency Containment Reserve (FCR) power by a virtual battery storage under certain conditions in Germany. First results show appropriate working of implemented control algorithms and reliability for different shareholders.


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