The Balloon-Borne Large Aperture Submillimeter Telescope Observatory
Ian Lowe, Gabriele Coppi, Peter A. R. Ade, Peter C. Ashton, Jason E. Austermann, James Beall, Susan Clark, Erin G. Cox, Mark J. Devlin, Simon Dicker, Bradley J.… 展开作者
Ian Lowe, Gabriele Coppi, Peter A. R. Ade, Peter C. Ashton, Jason E. Austermann, James Beall, Susan Clark, Erin G. Cox, Mark J. Devlin, Simon Dicker, Bradley J. Dober, Valentina Fanfani, Laura M. Fissel, Nicholas Galitzki, Jiansong Gao, Brandon Hensley, Johannes Hubmayr, Steven Li, Zhi-Yun Li, Nathan P. Lourie, Peter G. Martin, Philip Mauskopf, Federico Nati, Giles Novak, Giampaolo Pisano, L. Javier Romualdez, Adrian Sinclair, Juan D. Soler, Carole Tucker, Michael Vissers, Jordan Wheeler, Paul A. Williams, Mario Zannoni
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Presented at SPIE Ground-based and Airborne Telescopes VIII, December 13-18, 2020
The BLAST Observatory is a proposed superpressure balloon-borne polarimeter designed for a future ultra-long duration balloon campaign from Wanaka, New Zealand. To maximize scientific output while staying within the stringent superpressure weight envelope, BLAST will feature new 1.8m off-axis optical system contained within a lightweight monocoque structure gondola. The payload will incorporate a 300L $^4$He cryogenic receiver which will cool 8,274 microwave kinetic inductance detectors (MKIDs) to 100mK through the use of an adiabatic demagnetization refrigerator (ADR) in combination with a $^3$He sorption refrigerator all backed by a liquid helium pumped pot operating at 2K. The detector readout utilizes a new Xilinx RFSOC-based system which will run the next-generation of the BLAST-TNG KIDPy software. With this instrument we aim to answer outstanding questions about dust dynamics as well as provide community access to the polarized submillimeter sky made possible by high-altitude observing unrestricted by atmospheric transmission. The BLAST Observatory is designed for a minimum 31-day flight of which 70$\%$ will be dedicated to observations for BLAST scientific goals and the remaining 30$\%$ will be open to proposals from the wider astronomical community through a shared-risk proposals program.
The physical processes postulated to explain the high-energy emission mechanisms of compact astrophysical sources often yield polarised soft gamma rays (X-rays). PoGOLite is a balloon-borne polarimeter operating in the 25-80 keV energy band. The polarisation of incident photons is reconstructed using Compton scattering and photoelectric absorption in an array of phoswich detector cells comprising plastic and BGO scintillators, surrounded by a BGO side anticoincidence shield. The polarimeter is aligned to observation targets using a custom attitude control system. The maiden balloon flight is s…
We describe the development and implementation of a light-weight, fully autonomous 2-axis pointing and stabilization system designed for balloon-borne astronomical payloads. The system is developed using off-the-shelf components such as Arduino Uno controller, HMC 5883L magnetometer, MPU-9150 Inertial Measurement Unit (IMU) and iWave GPS receiver unit. It is a compact and rugged system which can also be used to take images/video in a moving vehicle, or in areal photography. The system performance is evaluated from the ground, as well as in conditions simulated to imitate the actual flight by u…
We present measurements of the electrical and thermal properties of new arrays of bolometeric detectors that were fabricated as part of a program to develop bolometers optimized for the low photon background of the EBEX balloon-borne experiment. An array consists of 140 spider-web transition edge sensor bolometers microfabricated on a 4" diameter silicon wafer. The designed average thermal conductance of bolometers on a proto-type array is 32 pW/K, and measurements are in good agreement with this value. The measurements are taken with newly developed, digital frequency domain multiplexer SQUID…
We use existing light weight balloon facility of Indian Centre for Space Physics to detect the X-ray radiation from Crab pulsar with a phoswich detector. We present the design considerations and characterization of the detector used for this purpose. We model the background radiation in the detector environment at various altitudes and use this in spectral analysis. The background radiation level and limitations on the detector allowed us to calculate minimum detection limit for extrasolar radiation sources with our set up.
The PoGO mission, including the PoGOLite Pathfinder and PoGO+, aims to provide polarimetric measurements of the Crab system and Cygnus X-1 in the hard X-ray band. Measurements are conducted from a stabilized balloon-borne platform, launched on a 1 million cubic meter balloon from the Esrange Space Center in Sweden to an altitude of approximately 40 km. Several flights have been conducted, resulting in two independent measurements of the Crab polarization and one of Cygnus X-1. Here, a review of the PoGO mission is presented, including a description of the payload and the flight campaigns, and …
Balloon-borne astronomy is a unique tool that allows for a level of image stability and significantly reduced atmospheric interference without the often prohibitive cost and long development time-scale that are characteristic of space-borne facility-class instruments. The Super-pressure Balloon-borne Imaging Telescope (SuperBIT) is a wide-field imager designed to provide 0.02" image stability over a 0.5 degree field-of-view for deep exposures within the visible-to-near-UV (300-900 um). As such, SuperBIT is a suitable platform for a wide range of balloon-borne observations, including solar and …
Detecting the first electron pairs with nuclear emulsion allows a precise measurement of the direction of incident gamma-rays as well as their polarization. With recent innovations in emulsion scanning, emulsion analyzing capability is becoming increasingly powerful. Presently, we are developing a balloon-borne gamma-ray telescope using nuclear emulsion. An overview and a status of our telescope is given.
We promote the precise gamma-ray observation project Gamma-Ray Astro-Imager with Nuclear Emulsion (GRAINE), which uses balloon-borne emulsion gamma-ray telescopes. The emulsion telescope realizes observations with high angular resolution, polarization sensitivity, and large aperture area in the 0.01--100 GeV energy region. Herein, we report the data analysis of emulsion tracks and the first demonstration of gamma-ray imaging via an emulsion telescope by using the flight data from the balloon experiment performed in 2015 (GRAINE 2015). The emulsion films were scanned by the latest read-out syst…
We report results obtained during the characterization of a commercial front-illuminated progressive scan interline transfer CCD camera. We demonstrate that the unmodified camera operates successfully in temperature and pressure conditions (-40C, 4mBar) representative of a high altitude balloon mission. We further demonstrate that the centroid of a well-sampled star can be determined to better than 2% of a pixel, even though the CCD is equipped with a microlens array. This device has been selected for use in a closed-loop star-guiding and tip-tilt correction system in the BIT-STABLE balloon mi…
We present the results of a study along with a first prototype of a high precision system (? 1 arcsec) for pointing and tracking light (near-infrared) telescopes on board stratospheric balloons. Such a system is essentially composed by a star sensor and by a star tracker, able to recognize the field and to adequately track the telescope, respectively. We present the software aimed at processing the star sensor image and the predictive algorithm that allows the fine tracking of the source at a sub-pixel level. The laboratory tests of the system are described and its performance is analyzed. We …
PoGOLite is a hard X-ray polarimeter operating in the 25-100 keV energy band. The instrument design is optimised for the observation of compact astrophysical sources. Observations are conducted from a stabilised stratospheric balloon platform at an altitude of approximately 40 km. The primary targets for first balloon flights of a reduced effective area instrument are the Crab and Cygnus-X1. The polarisation of incoming photons is determined using coincident Compton scattering and photo-absorption events reconstructed in an array of plastic scintillator detector cells surrounded by a bismuth g…
By detecting the beginning of electron pairs with nuclear emulsion, precise gamma-ray direction and gamma-ray polarization can be detected. With recent advancement in emulsion scanning system, emulsion analyzing capability is becoming powerful. Now we are developing the balloon-borne gamma-ray telescope with nuclear emulsion. Overview and status of our telescope is described.
The Balloon-Borne Cryogenic Telescope Testbed (BOBCAT) is a stratospheric balloon payload to develop technology for a future cryogenic suborbital observatory. A series of flights are intended to establish ultra-light dewar performance and open-aperture observing techniques for large (3--5 meter diameter) cryogenic telescopes at infrared wavelengths. An initial flight in 2019 demonstrated bulk transfer of liquid nitrogen and liquid helium at stratospheric altitudes. An 827 kg payload carried 14 liters of liquid nitrogen (LN2) and 268 liters of liquid helium (LHe) in pressurized storage dewars t…
Polarimetric observations of celestial sources in the hard X-ray band stand to provide new information on emission mechanisms and source geometries. PoGO+ is a Compton scattering polarimeter (20-150 keV) optimised for the observation of the Crab (pulsar and wind nebula) and Cygnus X-1 (black hole binary), from a stratospheric balloon-borne platform launched from the Esrange Space Centre in summer 2016. Prior to flight, the response of the polarimeter has been studied with polarised and unpolarised X-rays allowing a Geant4-based simulation model to be validated. The expected modulation factor f…
A precision measurement of the cosmic-ray positron spectrum may help to solve the puzzle of the nature of dark matter. Pairwise annihilation of neutralinos, predicted by some supersymmetric extensions to the standard model of particle physics, may leave a distinct feature in the cosmic-ray positron spectrum. As the available data are limited both in terms of statistics and energy range, we are developing a balloon-borne detector (PEBS) with a large acceptance of 4000 cm^2 sr. A superconducting magnet creating a field of 0.8 T and a tracking device consisting of scintillating fibers of 0.25 mm …
We describe here a focal plane array of Cold-Electron Bolometer (CEB) detectors integrated in a Frequency Selective Surface (FSS) for the 350 GHz detection band of the OLIMPO balloon-borne telescope. In our architecture, the two terminal CEB has been integrated in the periodic unit cell of the FSS structure and is impedance matched to the embedding impedance seen by it and provides a resonant interaction with the incident sub-mm radiation. The detector array has been designed to operate in background noise limited condition for incident powers of 20 pW to 80 pW, making it possible to use the s…
Indian Centre for Space Physics is engaged in pioneering balloon borne experiments with typical payloads less than ~ 3.5kg. Low cost rubber balloons are used to fly them to a height of about 40km. In a double balloon system, the booster balloon lifts the orbiter balloon to its cruising altitude where data is taken for a longer period of time. In this Paper, we present our first scientific report on the variation of Cosmic Rays and muons with altitude and detection of several solar flares in X-rays between 20keV and 100keV. We found the altitude of the Pfotzer maximum at Tropic of Cancer for co…
High energy polarization can be an indication of geometry, orientation, and other physical phenomena for a variety of sources, but has heretofore been a virtually unmeasured phenomenon. PoGOLite is a balloon-borne instrument intended to measure the polarization of X-rays between 25 and 100 keV. The pathfinder version of the instrument is scheduled to be launched from northern Sweden in summer 2013. The primary targets are the Crab pulsar and nebula and Cygnus X-1.
Balloon-borne astronomy is unique in that it allows for a level of image stability, resolution, and optical backgrounds that are comparable to space-borne systems due to greatly reduced atmospheric interference, but at a fraction of the cost and over a significantly reduced development time-scale. Instruments operating within visible-to-near-UV bands ($300$ - $900$ um) can achieve a theoretical diffraction limited resolution of $0.01"$ from the stratosphere ($35$ - $40$ km altitude) without the need for extensive adaptive optical systems required by ground-based systems. The {\it Superpressure…
The Balloon-borne Large Aperture Submillimeter Telescope (BLAST) operated successfully during a 250-hour flight over Antarctica in December 2006 (BLAST06). As part of the calibration and pointing procedures, the red hypergiant star VY CMa was observed and used as the primary calibrator. Details of the overall BLAST06 calibration procedure are discussed. The 1-sigma absolute calibration is accurate to 10, 12, and 13% at the 250, 350, and 500 micron bands, respectively. The errors are highly correlated between bands resulting in much lower error for the derived shape of the 250-500 micron contin…
The Balloon-borne Large Aperture Submillimeter Telescope for Polarimetry (BLASTPol) is a suborbital mapping experiment, designed to study the role played by magnetic fields in the star formation process. BLASTPol observes polarized light using a total power instrument, photolithographic polarizing grids, and an achromatic half-wave plate to modulate the polarization signal. During its second flight from Antarctica in December 2012, BLASTPol made degree scale maps of linearly polarized dust emission from molecular clouds in three wavebands, centered at 250, 350, and 500 microns. The instrumenta…
Balloon-borne astronomy offers an attractive option for experiments that require precise pointing and attitude stabilization, due to a large reduction in the atmospheric interference observed by ground-based systems as well as the low-cost and short development time-scale compared to space-borne systems. The Balloon-borne Imaging Testbed (BIT) is an instrument designed to meet the technological requirements of high precision astronomical missions and is a precursor to the development of a facility class instrument with capabilities similar to the Hubble Space Telescope. The attitude determinat…
The Next Generation Balloon-borne Large Aperture Submillimeter Telescope (BLAST-TNG) is a submillimeter mapping experiment planned for a 28 day long-duration balloon (LDB) flight from McMurdo Station, Antarctica during the 2018-2019 season. BLAST-TNG will detect submillimeter polarized interstellar dust emission, tracing magnetic fields in galactic molecular clouds. BLAST-TNG will be the first polarimeter with the sensitivity and resolution to probe the $\sim$0.1 parsec-scale features that are critical to understanding the origin of structures in the interstellar medium. With three detector ar…
PoGOLino is a balloon-borne scintillator-based experiment developed to study the largely unexplored high altitude neutron environment at high geomagnetic latitudes. The instrument comprises two detectors that make use of LiCAF, a novel neutron sensitive scintillator, sandwiched by BGO crystals for background reduction. The experiment was launched on March 20th 2013 from the Esrange Space Centre, Northern Sweden (geomagnetic latitude of $65^\circ$), for a three hour flight during which the instrument took data up to an altitude of 30.9 km. The detector design and ground calibration results are …
This paper describes the wave-front correction system developed for the Sunrise balloon telescope, and provides information about its in-flight performance. For the correction of low-order aberrations, a Correlating Wave-Front Sensor (CWS) was used. It consisted of a six-element Shack-Hartmann wave-front sensor (WFS), a fast tip-tilt mirror for the compensation of image motion, and an active telescope secondary mirror for focus correction. The CWS delivered a stabilized image with a precision of 0.04 arcsec (rms), whenever the coarse pointing was better than 90 arcsec peak-to-peak. The automat…
The Balloon-borne VLBI Experiment (BVEX) Radio Telescope and Position Tracking System
Queen’s University（女王大学）；Center for Astrophysics — Harvard & Smithsonian（哈佛-史密森尼天体物理中心）；Black Hole Initiative, Harvard University（哈佛大学黑洞倡议）；Dalhousie University（达尔豪斯大学）；Queen’s University, Smith School of Engineering（女王大学史密斯工程学院）；Queen’s University, Department of Mathematics and Statistics（女王大学数学与统计系）；MIT Haystack Observatory（麻省理工学院海斯塔克天文台）；Trottier Space Institute, McGill University（麦吉尔大学特罗蒂尔太空研究所）；McGill University（麦吉尔大学）；McMaster University（麦克马斯特大学）；StarSpec Technologies Inc.（StarSpec科技有限公司）；Johns Hopkins University（约翰斯·霍普金斯大学）；University of British Columbia（不列颠哥伦比亚大学）
The Debris Disk Explorer (DDX) is a proposed balloon-borne investigation of debris disks around nearby stars. Debris disks are analogs of the Asteroid Belt (mainly rocky) and Kuiper Belt (mainly icy) in our Solar System. DDX will measure the size, shape, brightness, and color of tens of disks. These measurements will enable us to place the Solar System in context. By imaging debris disks around nearby stars, DDX will reveal the presence of perturbing planets via their influence on disk structure, and explore the physics and history of debris disks by characterizing the size and composition of …
An attitude determination system for balloon-borne experiments is presented. The system provides pointing information in azimuth and elevation for instruments flying on stratospheric balloons over Antarctica. In-flight attitude is given by the real-time combination of readings from star cameras, a magnetometer, sun sensors, GPS, gyroscopes, tilt sensors and an elevation encoder. Post-flight attitude reconstruction is determined from star camera solutions, interpolated by the gyroscopes using an extended Kalman Filter. The multi-sensor system was employed by the Balloon-borne Large Aperture Sub…
This thesis discusses two different approaches for the measurement of cosmic-ray antiparticles in the GeV to TeV energy range. The first part of this thesis discusses the prospects of antiparticle flux measurements with the proposed PEBS detector. The project allots long duration balloon flights at one of Earth's poles at an altitude of 40 km. GEANT4 simulations were carried out which determine the atmospheric background and attenuation especially for antiparticles. The second part covers the AMS-02 experiment which will be installed in 2010 on the International Space Station at an altitude of…
We describe the design of the Sunrise Filter Imager (SuFI) and the Image Stabilization and Light Distribution (ISLiD) unit onboard the Sunrise balloon borne solar observatory. This contribution provides the necessary information which is relevant to understand the instruments working principles, the relevant technical data, and the necessary information about calibration issues directly related to the science data.
We investigate the observation of meteors with video cameras in stratospheric balloons, overcoming tropospheric handicaps like weather and extinction. We have studied the practical implementation of the idea, designed and tested instrumentation for balloon-borne missions. We have analysed the data of the Geminids 2016 campaign, determining the meteoroid flux just before the maximum. This text is an adaption of the work by the first author for his PhD Thesis: Techniques for near-Earth interplanetary matter detection and characterisation from optical ground-based observatories (Ocaña, 2017). Ref…
We present the thermal model of the Balloon-borne Large-Aperture Submillimeter Telescope for Polarimetry (BLASTPol). This instrument was successfully flown in two circumpolar flights from McMurdo, Antarctica in 2010 and 2012. During these two flights, BLASTPol obtained unprecedented information about the magnetic field in molecular clouds through the measurement of the polarized thermal emission of interstellar dust grains. The thermal design of the experiment addresses the stability and control of the payload necessary for this kind of measurement. We describe the thermal modeling of the payl…
The balloon-borne very long baseline interferometry (VLBI) experiment is a technical feasibility study for performing radio interferometry in the stratosphere. The flight model has been developed. A balloon-borne VLBI station will be launched to establish interferometric fringes with ground-based VLBI stations distributed over the Japanese islands at an observing frequency of approximately 20 GHz as the first step. This paper describes the system design and development of a series of observing instruments and bus systems. In addition to the advantages of avoiding the atmospheric effects of abs…
In the 50 years since the advent of X-ray astronomy there have been many scientific advances due to the development of new experimental techniques for detecting and characterising X-rays. Observations of X-ray polarisation have, however, not undergone a similar development. This is a shortcoming since a plethora of open questions related to the nature of X-ray sources could be resolved through measurements of the linear polarisation of emitted X-rays. The PoGOLite Pathfinder is a balloon-borne hard X-ray polarimeter operating in the 25 - 240 keV energy band from a stabilised observation platfo…
We are developing lumped-element kinetic inductance detectors (LEKIDs) designed to achieve background-limited sensitivity for far-infrared (FIR) spectroscopy on a stratospheric balloon. The Spectroscopic Terahertz Airborne Receiver for Far-InfraRed Exploration (STARFIRE) will study the evolution of dusty galaxies with observations of the [CII] 158 $μ$m and other atomic fine-structure transitions at $z=0.5-1.5$, both through direct observations of individual luminous infrared galaxies, and in blind surveys using the technique of line intensity mapping. The spectrometer will require large format…
The E and B Experiment (EBEX) was a long-duration balloon-borne cosmic microwave background polarimeter that flew over Antarctica in 2013. We describe the experiment's optical system, receiver, and polarimetric approach, and report on their in-flight performance. EBEX had three frequency bands centered on 150, 250, and 410 GHz. To make efficient use of limited mass and space we designed a 115 cm$^{2}$sr high throughput optical system that had two ambient temperature mirrors and four anti-reflection coated polyethylene lenses per focal plane. All frequency bands shared the same optical train. P…
The Balloon-borne Large Aperture Submillimeter Telescope for Polarimetry (BLAST-Pol) is a suborbital mapping experiment designed to study the role played by magnetic fields in the star formation process. BLAST-Pol is the reconstructed BLAST telescope, with the addition of linear polarization capability. Using a 1.8 m Cassegrain telescope, BLAST-Pol images the sky onto a focal plane that consists of 280 bolometric detectors in three arrays, observing simultaneously at 250, 350, and 500 um. The diffraction-limited optical system provides a resolution of 30'' at 250 um. The polarimeter consists o…
X-ray polarimetry has seen a growing interest in recent years. Improvements in detector technology and focusing X-ray optics now enable sensitive astrophysical X-ray polarization measurements. These measurements will provide new insights into the processes at work in accreting black holes, the emission of X-rays from neutron stars and magnetars, and the structure of AGN jets. X-Calibur is a balloon-borne hard X-ray scattering polarimeter. An X-ray mirror with a focal length of 8 m focuses X-rays onto the detector, which consists of a plastic scattering element surrounded by Cadmium-Zinc-Tellur…
EBEX was a long-duration balloon-borne experiment to measure the polarization of the cosmic microwave background. The experiment had three frequency bands centered at 150, 250, and 410 GHz and was the first to use a kilo-pixel array of transition edge sensor (TES) bolometers aboard a balloon platform; shortly after reaching float we operated 504, 342, and 109 TESs at each of the bands, respectively. We describe the design and characterization of the array and the readout system. We give the distributions of measured thermal conductances, normal resistances, and transition temperatures. With th…
We present our work to develop and characterize low thermal conductance bolometers that are part of sinuous antenna multi-chroic pixels (SAMP). We use longer, thinner and meandered bolometer legs to achieve 9 pW/K thermal conductance bolometers. We also discuss the development of inductor-capacitor chips operated at 4 K to extend the multiplexing factor of the frequency domain multiplexing to 105, an increase of 60% compared to the factor currently demonstrated for this readout system. This technology development is motivated by EBEX-IDS, a balloon-borne polarimeter designed to characterize th…
Fireball-II is a NASA/CNES balloon-borne telescope and MOS to study faint diffuse emissions of galaxies in the space ultraviolet. The MOS is based on two identical reflective Schmidt systems sharing an plane-aspherized grating obtained by active optics methods.
Atmosphere layers, especially the troposphere, hinder the astronomical observation. For more than 100 years astronomers have tried observing from balloons to avoid turbulence and extinction. New developments in cardsize computers, RF equipment and satellite navigation have democratised the access to the stratosphere. As a result of a ProAm collaboration with the Daedalus Team we have developed a low-cost multi-purpose platform with stratospheric balloons carrying up to 3 kg of scientific payload. The Daedalus Team is an amateur group that has been launching sounding probes since 2010. Since th…
We introduce the light-weight carbon fiber and aluminum gondola designed for the SPIDER balloon-borne telescope. SPIDER is designed to measure the polarization of the Cosmic Microwave Background radiation with unprecedented sensitivity and control of systematics in search of the imprint of inflation: a period of exponential expansion in the early Universe. The requirements of this balloon-borne instrument put tight constrains on the mass budget of the payload. The SPIDER gondola is designed to house the experiment and guarantee its operational and structural integrity during its balloon-borne …
Energy estimation of direct and reflected cosmic-ray events aboard balloon-borne radio detectors
Instituto Galego de Física de Altas Enerxías (IGFAE) & Universidade de Santiago de Compostela（加利西亚高能物理研究所与圣地亚哥德孔波斯特拉大学）；Instituto de Física La Plata, CONICET-UNLP（拉普拉塔物理研究所，阿根廷国家科学研究委员会-拉普拉塔国立大学）
At a fraction the total cost of an equivalent orbital mission, scientific balloon-borne platforms, operating above 99.7% of the Earth's atmosphere, offer attractive, competitive, and effective observational capabilities -- namely space-like resolution, transmission, and backgrounds -- that are well suited for modern astronomy and cosmology. SuperBIT is a diffraction-limited, wide-field, 0.5 m telescope capable of exploiting these observing conditions in order to provide exquisite imaging throughout the near-IR to near-UV. It utilizes a robust active stabilization system that has consistently d…
CREAM (Cosmic Ray Energetics And Mass) is a multi-flight balloon mission designed to collect direct data on the elemental composition and individual energy spectra of cosmic rays. Two instrument suites have been built to be flown alternately on a yearly base. The tungsten/Sci-Fi imaging calorimeter for the second flight, scheduled for December 2005, was calibrated with electron and proton beams at CERN. A calibration procedure based on the study of the longitudinal shower profile is described and preliminary results of the beam test are presented.
Sub-Kelvin Cryogenics for a Super-Pressure Balloon-Borne CMB Polarimeter: Taurus
Case Western Reserve University（凯斯西储大学）；University of California, Berkeley（加州大学伯克利分校）；Lawrence Berkeley National Laboratory（劳伦斯伯克利国家实验室）；National Institute of Standards and Technology（美国国家标准与技术研究院）；Princeton University（普林斯顿大学）；University of Colorado Boulder（科罗拉多大学博尔德分校）；University of Illinois Urbana-Champaign（伊利诺伊大学厄巴纳-香槟分校）；University of Iceland（冰岛大学）；Stockholm University（斯德哥尔摩大学）
PoGOLite is a balloon-borne hard X-ray polarimeter dedicated to the study of point sources. Compton scattered events are registered using an array of plastic scintillator units to determine the polarisation of incident X-rays in the energy range 20 - 240 keV. In 2013, a near circumpolar balloon flight of 14 days duration was completed after launch from Esrange, Sweden, resulting in a measurement of the linear polarisation of the Crab emission. Building on the experience gained from this Pathfinder flight, the polarimeter is being modified to improve performance for a second flight in 2016. Suc…
Multi-sensor fusion for fine-guidance and milliarcsecond-level attitude estimation of balloon-borne telescope
Princeton University（普林斯顿大学）；New York University（纽约大学）；Northeastern University（东北大学）；StarSpec Technologies Inc.（StarSpec科技有限公司）；University of Toronto（多伦多大学）；Durham University（杜伦大学）；California Institute of Technology（加州理工学院）；University of Arizona（亚利桑那大学）；National Research Council Canada Herzberg Astronomy and Astrophysics Research Centre（加拿大国家研究委员会赫茨伯格天文学和天体物理学研究中心）；EPFL（洛桑联邦理工学院）；Imperial College（帝国理工学院）
The Polarized Instrument for Long-wavelength Observation of the Tenuous interstellar medium (PILOT) is a balloon-borne experiment aiming at measuring the polarized emission of thermal dust at a wavelength of 240 mm (1.2 THz). A first PILOT flight (flight#1) of the experiment took place from Timmins, Ontario, Canada, in September 2015 and a second flight (flight#2) took place from Alice Springs, Australia in april 2017. In this paper, we present the inflight performance of the instrument during these two flights. We concentrate on performances during flight#2, but allude to flight#1 performance…
We present the second generation BLASTbus electronics. The primary purposes of this system are detector readout, attitude control, and cryogenic housekeeping, for balloon-borne telescopes. Readout of neutron transmutation doped germanium (NTD-Ge) bolometers requires low noise and parallel acquisition of hundreds of analog signals. Controlling a telescope's attitude requires the capability to interface to a wide variety of sensors and motors, and to use them together in a fast, closed loop. To achieve these different goals, the BLASTbus system employs a flexible motherboard-daughterboard archit…
We present the technology and control methods developed for the pointing system of the SPIDER experiment. SPIDER is a balloon-borne polarimeter designed to detect the imprint of primordial gravitational waves in the polarization of the Cosmic Microwave Background radiation. We describe the two main components of the telescope's azimuth drive: the reaction wheel and the motorized pivot. A 13 kHz PI control loop runs on a digital signal processor, with feedback from fibre optic rate gyroscopes. This system can control azimuthal speed with < 0.02 deg/s RMS error. To control elevation, SPIDER uses…
