Reference Specifications (December 2025)

FASR is designed to perform Fourier synthesis imaging using well-established interferometric techniques. For an array of N antennas there are approximately N²/2 independent antenna pairs, each of which measures a single Fourier component (a complex visibility) of the Sun’s radio brightness distribution at a given frequency, time, and spatial scale. The ensemble of antenna baselines therefore measures many Fourier components. Fourier inversion of the visibility measurements yields an image of the Sun’s radio brightness at a given frequency, time, and polarization. Deconvolution techniques are then used to remove the effects of the point spread function, the response of the instrument to a point source.

FASR observations will cover an unprecedented two-orders-of-magnitude frequency range, 0.2 to 20 GHz (wavelengths from 1.5 cm to 1.5 m), using two separate arrays of antennas, denoted FASR A and FASR B. Each array provides frequency coverage over roughly a decade of bandwidth: ~2–20 (possibly 30) GHz (FASR A) and 200 MHz–2 GHz (FASR B). The number, type, and configuration of the antennas in each array are chosen to address the key science objectives. The antennas will be distributed over an area with a diameter of ~4 km, providing an angular resolution of 1″ at 20 GHz; angular resolution scales linearly with wavelength from this fiducial value.

The table below shows the current reference specifications:

Reference FASR Specifications

The working reference design below is evolving with community input—new science use cases help refine these targets and trade-offs.