Sub-milliarcsecond astronomical imaging: advancing space-based astronomical optical interferometry observatories with Optimast

Belle, G. T. van; Hillsberry, Daniel; Piness, Jessica; Kugler, Justin

doi:10.1117/12.2630597

Cited by 2 publications

(2 citation statements)

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Section: Introductionmentioning

confidence: 99%

Space interferometer imaging limitations due to Global Positioning System uncertainties and parasitic forces in Low Earth Orbit

Pogorelyuk,

Black,

Belsten

et al. 2024

J. Astron. Telesc. Instrum. Syst.

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Space interferometers could, in principle, exploit the relatively stable space environment and ease of baseline reconfiguration to collect measurements beyond the limitations of ground-based interferometers. In particular, a two-element interferometer could provide excellent uv-plane coverage over a few tens of low Earth orbits. One of the challenges for free-flying interferometers is controlling the optical path distance with subwavelength accuracies despite the collectors flying up to hundreds of meters apart. We consider two approaches: an artificial in-orbit laser guide star (LGS) that provides a phase reference for the space interferometer and fringe tracking on the science target itself. The two approaches (LGS versus no LGS) would require different image processing techniques. In this work, we explore image processing with LGS phase residuals due to global positioning system (GPS) uncertainties. We use GPS uncertainties from the Gravity Recovery and Climate Experiment Follow-On mission to simulate image retrieval with a 300-m baseline laser-guided space interferometer. This is done by fitting the slowly varying phase errors of complex visibility measurements. We also consider a 40-m baseline interferometer with visibility(-modulus)-only measurements. In this case, we simulate the bias in visibility due to fringe tracking in the presence of parasitic forces acting on the spacecraft. We then use a modified version of the hybrid input-output phase retrieval algorithm for image reconstruction. We conclude that under our optimistic assumptions, both approaches could enable general imaging of a few large stars even with CubeSats, although an LGS would significantly improve the best resolution obtainable.

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Section: Introductionmentioning

confidence: 99%

Space interferometer imaging limitations due to Global Positioning System uncertainties and parasitic forces in Low Earth Orbit

Pogorelyuk,

Black,

Belsten

et al. 2024

J. Astron. Telesc. Instrum. Syst.

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“…The LGS would help with fringe tracking and provide a phase reference. Structurally connected interferometers could also potentially reach tens-of-meters baselines on small satellite platforms 17 to demonstrate some of the technologies required for future large missions. The question we begin to address here is whether a space-interferometer technology demonstration mission can provide unique science.…”

Section: Introductionmentioning

confidence: 99%

Space interferometer imaging limitations due to GPS uncertainties and parasitic forces in LEO

Pogorelyuk,

Black,

Belsten

et al. 2023

UV/Optical/IR Space Telescopes and Instruments: Innovative Technologies and Concepts XI

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Space interferometers could, in principle, exploit the relatively stable space environment and ease of baseline reconfiguration to collect measurements beyond the limitations of ground-based interferometers. In particular, a two-element interferometer could provide excellent uv-plane coverage over a few tens of low-Earth orbits. One of the challenges for free-flying interferometers is controlling the optical path distance with sub-wavelength accuracies despite the collectors flying up to hundreds of meters apart. This work considers two approaches: an artificial in-orbit laser guide star (LGS) that provides a phase reference for the space interferometer and fringe tracking on the science target itself. The two approaches (LGS vs. no LGS) would require different image processing techniques. In this work, we explore image processing with LGS phase residuals due to GPS uncertainties. We use GPS uncertainties from the GRACE-FO mission to simulate image retrieval with a 300 m baseline laser-guided space interferometer. This is done by fitting the slowly varying phase errors of complex visibility measurements. We also consider a 40 m baseline interferometer with visibility(-modulus)-only measurements. In this case, we simulate the bias in visibility due to fringe tracking in the presence of parasitic forces acting on the spacecraft. We then use a modified version of the Hybrid Input-Output phase retrieval algorithm for image reconstruction. We conclude that under our optimistic assumptions, both approaches could enable general imaging of a few large stars even with CubeSats, although an LGS would significantly improve the best resolution obtainable.

show abstract

Sub-milliarcsecond astronomical imaging: advancing space-based astronomical optical interferometry observatories with Optimast

Cited by 2 publications

References 0 publications

Space interferometer imaging limitations due to Global Positioning System uncertainties and parasitic forces in Low Earth Orbit

Space interferometer imaging limitations due to Global Positioning System uncertainties and parasitic forces in Low Earth Orbit

Space interferometer imaging limitations due to GPS uncertainties and parasitic forces in LEO

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