S. Maher

The Wide-Field Imaging Interferometry Testbed (WIIT): Recent Progress and Results

Research with the Wide-Field Imaging Interferometry Testbed (WIIT) is ongoing, and in the past year we have achieved several important milestones. We have moved WIIT into the Advanced Interferometry and Metrology (AIM) Laboratory at Goddard, and have characterized the testbed in this well-controlled environment. The system is now completely automated and we are in the process of acquiring large data sets for analysis. In this paper, we discuss these new developments and outline our future research directions. The WIIT testbed, combined with new data analysis techniques and algorithms, provides a demonstration of the technique of wide-field interferometric imaging, a powerful tool for future space-borne interferometers. Algorithm development is discussed in a separate paper within this conference.

Design and status of the Balloon Experimental Twin Telescope for infrared interferometry (BETTII): an interferometer at the edge of space

The Balloon Experimental Twin Telescope for Infrared Interferometry (BETTII) is an 8-meter baseline far-infrared interferometer designed to fly on a high altitude balloon. BETTII uses a double-Fourier Michelson interferometer to simultaneously obtain spatial and spectral information on science targets; the long baseline permits subarcsecond angular resolution, a capability unmatched by other far-infrared facilities. Here, we present key aspects of the overall design of the mission and provide an overview of the current status of the project. We also discuss briefly the implications of this experiment for future space-based far-infrared interferometers.

Building an interferometer at the edge of space: pointing and phase control system for BETTII

We propose an architecture for the control system of BETTII,1 a far-infrared, balloon-borne interferometer with a baseline of 8 meters. This system involves multiple synchronized control loops for real-time pointing control and precise attitude knowledge. This will enable accurate phase estimation and control, a necessity for successful interferometry. We present the overall control strategy and describe our flight hardware in detail. We also show our current test setup and the first results of our coarse pointing loop.

The balloon experimental twin telescope for infrared interferometry (BETTII): interferometry at the edge of the atmosphere

The Balloon Experimental Twin Telescope for Infrared Interferometry (BETTII) is an 8-meter baseline far-infrared interferometer designed to fly on a high altitude balloon. BETTII uses a double-Fourier Michelson interferometer to simultaneously obtain spatial and spectral information on science targets; the long baseline permits subarcsecond angular resolution, a capability unmatched by other far-infrared facilities. This program started in 2011, and is now in the process of building and testing components of the mission, aiming for first flight in fall of 2015. This paper will provide an overview of the BETTII experiment, with a discussion of current progress and of future plans.

The Balloon Experimental Twin Telescope for Infrared Interferometry (BETTII): towards the first flight

The Balloon Experimental Twin Telescope for Infrared Interferometry (BETTII) is a balloon-borne, far-infrared direct detection interferometer with a baseline of 8 m and two collectors of 50 cm. It is designed to study galactic clustered star formation by providing spatially-resolved spectroscopy of nearby star clusters. It is being assembled and tested at NASA Goddard Space Flight Center for a first flight in Fall 2016. We report on recent progress concerning the pointing control system and discuss the overall status of the project as it gets ready for its commissioning flight.

Developing spatio-spectral interferometry in the lab for far-IR space applications

We describe a NASA-sponsored project to develop and learn the practical limitations of wide-field spatio-spectral interferometry, a technique that will enable the acquisition of high-resolution far-IR integral field spectroscopic data with a future space-based interferometer.

A control system for BETTII: enabling far-infrared, balloon-borne Fourier transform spectroscopy

BETTII, a balloon-borne double-Fourier interferometer, requires precise control of the relative phase and angle between the beams to enable Fourier transform spectroscopy. The control system and its challenges are presented.