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Pivot-Only Azimuthal Control and Attitude Estimation of Balloon-borne Payloads
Authors:
Philippe Voyer,
Simon Tartakovsky,
Steven J. Benton,
William C. Jones
Abstract:
This paper presents an attitude estimation and yaw-rate control framework for balloon-borne payloads using pivot-only actuation, motivated by the Taurus experiment. Taurus is a long-duration balloon instrument designed for rapid azimuthal scanning at approximately 30 deg/s using a motorized pivot at the flight-train connection, without a reaction wheel. We model the gondola as a rigid body subject…
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This paper presents an attitude estimation and yaw-rate control framework for balloon-borne payloads using pivot-only actuation, motivated by the Taurus experiment. Taurus is a long-duration balloon instrument designed for rapid azimuthal scanning at approximately 30 deg/s using a motorized pivot at the flight-train connection, without a reaction wheel. We model the gondola as a rigid body subject to realistic disturbances and sensing limitations, and implement a Multiplicative Extended Kalman Filter (MEKF) that estimates attitude and gyroscope bias by fusing inertial and vector-camera measurements. A simple PI controller uses the estimated states to regulate yaw rate. Numerical simulations incorporating representative disturbance and measurement noise levels are used to evaluate closed-loop control performance and MEKF behavior under flight-like conditions. Experimental tests on the Taurus gondola validate the pivot-only approach, demonstrating stable high-rate tracking under realistic hardware constraints. The close agreement between simulation and experiment indicates that the simplified rigid-body model captures the dominant dynamics relevant for controller design and integrated estimation-and-control development.
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Submitted 12 December, 2025;
originally announced December 2025.
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$τ$HK: a modular housekeeping system for cryostats and balloon payloads
Authors:
Simon Tartakovsky,
Steven J. Benton,
Aurelien A. Fraisse,
William C. Jones,
Jared L. May,
Johanna M. Nagy,
Ricardo R. Rodriguez,
Philippe Voyer
Abstract:
$τ$HK is a versatile experiment housekeeping (HK) system designed to perform cryogenic temperature readout and heater control on the upcoming Taurus balloon experiment. $τ…
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$τ$HK is a versatile experiment housekeeping (HK) system designed to perform cryogenic temperature readout and heater control on the upcoming Taurus balloon experiment. $τ$HK, more broadly, is also suitable for ambient-temperature applications and general-purpose experiment input and output. It is built around an IEEE Eurocard subrack capable of housing up to 16 interchangeable daughter cards, allowing a fully populated system to support as many as 256 independent channels while drawing under 7.5\,W. This modular architecture allows experiments to expand on the existing daughter cards with ones tailored to their specific needs. There are currently three flavors of daughter cards: Resistive Temperature Device (RTD) readout, general purpose thermometer bias and readout, and load driver. The RTD board consists of a low noise lock-in amplifier that is limited only by device sensitivity over all temperature ranges. The general-purpose bias and readout board with chopping capability is primarily designed for thermometer diodes, but flexible enough to accommodate room temperature thermistors, Wheatstone bridges, optical encoders, and other devices. Finally, the load driver card can output an analog voltage for precise cryogenic heaters or it can be used to pulse width modulate high power loads. $τ$HK is a power efficient solution for experimental housekeeping needs that is suited for the the harsh environment of stratospheric ballooning.
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Submitted 12 May, 2025;
originally announced May 2025.
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Thermal architecture for a cryogenic super-pressure balloon payload: design and development of the Taurus flight cryostat
Authors:
Simon Tartakovsky,
Alexandre E. Adler,
Jason E. Austermann,
Steven J. Benton,
Rick Bihary,
Malcolm Durking,
Shannon M. Duff,
Jeffrey P. Filippini,
Aurelien A. Fraisse,
Thomas J. L. J. Gascard,
Sho M. Gibbs,
Suren Gourapura,
Jon E. Gudmundsson,
John W. Hartley,
Johannes Hubmayr,
William C. Jones,
Steven Li,
Jared L. May,
Johanna M. Nagy,
Kate Okun,
Ivan L. Padilla,
L. Javier Romualdez,
Michael R. Vissers
Abstract:
We describe the cryogenic system being developed for Taurus: a super-pressure balloon-borne microwave polarimeter scheduled to fly in 2027. The Taurus cryogenic system consists of a 660L liquid helium cryostat which achieves a base temperature of <100mK with the help of a capillary-fed superfluid tank and a closed cycle dilution refrigerator. The main tank is supported with fiberglass flexures and…
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We describe the cryogenic system being developed for Taurus: a super-pressure balloon-borne microwave polarimeter scheduled to fly in 2027. The Taurus cryogenic system consists of a 660L liquid helium cryostat which achieves a base temperature of <100mK with the help of a capillary-fed superfluid tank and a closed cycle dilution refrigerator. The main tank is supported with fiberglass flexures and is encased in two layers of vapor-cooled shields which allow Taurus to make full use of the extended flight time offered by the super-pressure balloon platform. The Taurus cryostat is projected to hold for over 50 days while weighing under 1000lbs. We present the design, testing, and thermal analysis of the Taurus cryogenic systems.
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Submitted 22 October, 2024;
originally announced October 2024.
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In-Flight Performance of Spider's 280 GHz Receivers
Authors:
Elle C. Shaw,
P. A. R. Ade,
S. Akers,
M. Amiri,
J. Austermann,
J. Beall,
D. T. Becker,
S. J. Benton,
A. S. Bergman,
J. J. Bock,
J. R. Bond,
S. A. Bryan,
H. C. Chiang,
C. R. Contaldi,
R. S. Domagalski,
O. Doré,
S. M. Duff,
A. J. Duivenvoorden,
H. K. Eriksen,
M. Farhang,
J. P. Filippini,
L. M. Fissel,
A. A. Fraisse,
K. Freese,
M. Galloway
, et al. (62 additional authors not shown)
Abstract:
SPIDER is a balloon-borne instrument designed to map the cosmic microwave background at degree-angular scales in the presence of Galactic foregrounds. SPIDER has mapped a large sky area in the Southern Hemisphere using more than 2000 transition-edge sensors (TESs) during two NASA Long Duration Balloon flights above the Antarctic continent. During its first flight in January 2015, SPIDER observed i…
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SPIDER is a balloon-borne instrument designed to map the cosmic microwave background at degree-angular scales in the presence of Galactic foregrounds. SPIDER has mapped a large sky area in the Southern Hemisphere using more than 2000 transition-edge sensors (TESs) during two NASA Long Duration Balloon flights above the Antarctic continent. During its first flight in January 2015, SPIDER observed in the 95 GHz and 150 GHz frequency bands, setting constraints on the B-mode signature of primordial gravitational waves. Its second flight in the 2022-2023 season added new receivers at 280 GHz, each using an array of TESs coupled to the sky through feedhorns formed from stacks of silicon wafers. These receivers are optimized to produce deep maps of polarized Galactic dust emission over a large sky area, providing a unique data set with lasting value to the field. We describe the instrument's performance during SPIDER's second flight, focusing on the performance of the 280 GHz receivers. We include details on the flight, in-band optical loading at float, and an early analysis of detector noise.
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Submitted 17 August, 2025; v1 submitted 19 August, 2024;
originally announced August 2024.
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Instrument Overview of Taurus: A Balloon-borne CMB and Dust Polarization Experiment
Authors:
Jared L. May,
Alexandre E. Adler,
Jason E. Austermann,
Steven J. Benton,
Rick Bihary,
Malcolm Durkin,
Shannon M. Duff,
Jeffrey P. Filippini,
Aurelien A. Fraisse,
Thomas J. L. J. Gascard,
Sho M. Gibbs,
Suren Gourapura,
Jon E. Gudmundsson,
John W. Hartley,
Johannes Hubmayr,
William C. Jones,
Steven Li,
Johanna M. Nagy,
Kate Okun,
Ivan L. Padilla,
L. Javier Romualdez,
Simon Tartakovsky,
Michael R. Vissers
Abstract:
Taurus is a balloon-borne cosmic microwave background (CMB) experiment optimized to map the E-mode polarization and Galactic foregrounds at the largest angular scales ($\ell$ $\lt$ 30) and improve measurements of the optical depth to reionization ($τ$). This will pave the way for improved measurements of the sum of neutrino masses in combination with high-resolution CMB data while also testing the…
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Taurus is a balloon-borne cosmic microwave background (CMB) experiment optimized to map the E-mode polarization and Galactic foregrounds at the largest angular scales ($\ell$ $\lt$ 30) and improve measurements of the optical depth to reionization ($τ$). This will pave the way for improved measurements of the sum of neutrino masses in combination with high-resolution CMB data while also testing the $ΛCDM$ model on large angular scales and providing high-frequency maps of polarized dust foregrounds to the CMB community. These measurements take advantage of the low-loading environment found in the stratosphere and are enabled by NASA's super-pressure balloon platform, which provides access to 70% of the sky with a launch from Wanaka, New Zealand. Here we describe a general overview of Taurus, with an emphasis on the instrument design. Taurus will employ more than 10,000 100 mK transition edge sensor bolometers distributed across two low-frequency (150, 220 GHz) and one high-frequency (280, 350 GHz) dichroic receivers. The liquid helium cryostat housing the detectors and optics is supported by a lightweight gondola. The payload is designed to meet the challenges in mass, power, and thermal control posed by the super-pressure platform. The instrument and scan strategy are optimized for rigorous control of instrumental systematics, enabling high-fidelity linear polarization measurements on the largest angular scales.
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Submitted 13 July, 2024; v1 submitted 1 July, 2024;
originally announced July 2024.
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Modeling optical systematics for the Taurus CMB experiment
Authors:
Alexandre E. Adler,
Jason E. Austermann,
Steven J. Benton,
Shannon M. Duff,
Jeffrey P. Filippini,
Aurelien A. Fraisse,
Thomas Gascard,
Sho M. Gibbs,
Suren Gourapura,
Johannes Hubmayr,
Jon E. Gudmundsson,
William C. Jones,
Jared L. May,
Johanna M. Nagy,
Kate Okun,
Ivan Padilla,
Christopher Rooney,
Simon Tartakovsky,
Michael R. Vissers
Abstract:
We simulate a variety of optical systematics for Taurus, a balloon-borne cosmic microwave background (CMB) polarisation experiment, to assess their impact on large-scale E-mode polarisation measurements and constraints of the optical depth to reionisation τ. We model a one-month flight of Taurus from Wanaka, New Zealand aboard a super-pressure balloon (SPB). We simulate night-time scans of both th…
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We simulate a variety of optical systematics for Taurus, a balloon-borne cosmic microwave background (CMB) polarisation experiment, to assess their impact on large-scale E-mode polarisation measurements and constraints of the optical depth to reionisation τ. We model a one-month flight of Taurus from Wanaka, New Zealand aboard a super-pressure balloon (SPB). We simulate night-time scans of both the CMB and dust foregrounds in the 150GHz band, one of Taurus's four observing bands. We consider a variety of possible systematics that may affect Taurus's observations, including non-gaussian beams, pointing reconstruction error, and half-wave plate (HWP) non-idealities. For each of these, we evaluate the residual power in the difference between maps simulated with and without the systematic, and compare this to the expected signal level corresponding to Taurus's science goals. Our results indicate that most of the HWP-related systematics can be mitigated to be smaller than sample variance by calibrating with Planck's TT spectrum and using an achromatic HWP model, with a preference for five layers of sapphire to ensure good systematic control. However, additional beam characterization will be required to mitigate far-sidelobe pickup from dust on larger scales.
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Submitted 2 October, 2024; v1 submitted 17 June, 2024;
originally announced June 2024.
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The Hydrogen Intensity and Real-time Analysis eXperiment: 256-Element Array Status and Overview
Authors:
Devin Crichton,
Moumita Aich,
Adam Amara,
Kevin Bandura,
Bruce A. Bassett,
Carlos Bengaly,
Pascale Berner,
Shruti Bhatporia,
Martin Bucher,
Tzu-Ching Chang,
H. Cynthia Chiang,
Jean-Francois Cliche,
Carolyn Crichton,
Romeel Dave,
Dirk I. L. de Villiers,
Matt A. Dobbs,
Aaron M. Ewall-Wice,
Scott Eyono,
Christopher Finlay,
Sindhu Gaddam,
Ken Ganga,
Kevin G. Gayley,
Kit Gerodias,
Tim Gibbon,
Austin Gumba
, et al. (75 additional authors not shown)
Abstract:
The Hydrogen Intensity and Real-time Analysis eXperiment (HIRAX) is a radio interferometer array currently in development, with an initial 256-element array to be deployed at the South African Radio Astronomy Observatory (SARAO) Square Kilometer Array (SKA) site in South Africa. Each of the 6m, $f/0.23$ dishes will be instrumented with dual-polarisation feeds operating over a frequency range of 40…
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The Hydrogen Intensity and Real-time Analysis eXperiment (HIRAX) is a radio interferometer array currently in development, with an initial 256-element array to be deployed at the South African Radio Astronomy Observatory (SARAO) Square Kilometer Array (SKA) site in South Africa. Each of the 6m, $f/0.23$ dishes will be instrumented with dual-polarisation feeds operating over a frequency range of 400-800 MHz. Through intensity mapping of the 21 cm emission line of neutral hydrogen, HIRAX will provide a cosmological survey of the distribution of large-scale structure over the redshift range of $0.775 < z < 2.55$ over $\sim$15,000 square degrees of the southern sky. The statistical power of such a survey is sufficient to produce $\sim$7 percent constraints on the dark energy equation of state parameter when combined with measurements from the Planck satellite. Additionally, HIRAX will provide a highly competitive platform for radio transient and HI absorber science while enabling a multitude of cross-correlation studies. In this paper, we describe the science goals of the experiment, overview of the design and status of the sub-components of the telescope system, and describe the expected performance of the initial 256-element array as well as the planned future expansion to the final, 1024-element array.
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Submitted 17 January, 2022; v1 submitted 28 September, 2021;
originally announced September 2021.
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Radio-Frequency Interference at the McGill Arctic Research Station
Authors:
T. Dyson,
H. C. Chiang,
E. Egan,
N. Ghazi,
T. Menard,
R. A. Monsalve,
T. Moso,
J. Peterson,
J. L. Sievers,
S. Tartakovsky
Abstract:
The frequencies of interest for redshifted 21 cm observations are heavily affected by terrestrial radio-frequency interference (RFI). We identify the McGill Arctic Research Station (MARS) as a new RFI-quiet site and report its RFI occupancy using 122 hours of data taken with a prototype antenna station developed for the Array of Long-Baseline Antennas for Taking Radio Observations from the Sub-Ant…
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The frequencies of interest for redshifted 21 cm observations are heavily affected by terrestrial radio-frequency interference (RFI). We identify the McGill Arctic Research Station (MARS) as a new RFI-quiet site and report its RFI occupancy using 122 hours of data taken with a prototype antenna station developed for the Array of Long-Baseline Antennas for Taking Radio Observations from the Sub-Antarctic. Using an RFI flagging process tailored to the MARS data, we find an overall RFI occupancy of 1.8% averaged over 20-125 MHz. In particular, the FM broadcast band (88-108 MHz) is found to have an RFI occupancy of at most 1.6%. The data were taken during the Arctic summer, when degraded ionospheric conditions and an active research base contributed to increased RFI. The results quoted here therefore represent the maximum-level RFI environment at MARS.
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Submitted 11 December, 2020;
originally announced December 2020.
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The Array of Long Baseline Antennas for Taking Radio Observations from the Sub-Antarctic
Authors:
H. C. Chiang,
T. Dyson,
E. Egan,
S. Eyono,
N. Ghazi,
J. Hickish,
J. M. Jauregui-Garcia,
V. Manukha,
T. Menard,
T. Moso,
J. Peterson,
L. Philip,
J. L. Sievers,
S. Tartakovsky
Abstract:
Measurements of redshifted 21-cm emission of neutral hydrogen at <30 MHz have the potential to probe the cosmic "dark ages," a period of the universe's history that remains unobserved to date. Observations at these frequencies are exceptionally challenging because of bright Galactic foregrounds, ionospheric contamination, and terrestrial radio-frequency interference. Very few sky maps exist at <30…
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Measurements of redshifted 21-cm emission of neutral hydrogen at <30 MHz have the potential to probe the cosmic "dark ages," a period of the universe's history that remains unobserved to date. Observations at these frequencies are exceptionally challenging because of bright Galactic foregrounds, ionospheric contamination, and terrestrial radio-frequency interference. Very few sky maps exist at <30 MHz, and most have modest resolution. We introduce the Array of Long Baseline Antennas for Taking Radio Observations from the Sub-Antarctic (ALBATROS), a new experiment that aims to image low-frequency Galactic emission with an order-of-magnitude improvement in resolution over existing data. The ALBATROS array will consist of antenna stations that operate autonomously, each recording baseband data that will be interferometrically combined offline. The array will be installed on Marion Island and will ultimately comprise 10 stations, with an operating frequency range of 1.2-125 MHz and maximum baseline lengths of ~20 km. We present the ALBATROS instrument design and discuss pathfinder observations that were taken from Marion Island during 2018-2019.
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Submitted 21 November, 2020; v1 submitted 27 August, 2020;
originally announced August 2020.