R-MXAS is a revolutionary aerospace architecture for realizing a synthetic aperture imaging radiometer (SAIR) in a manner affording unprecedented sparsity in terms of number of antenna elements. As such, it enables a feasible path to space-based implementation of RF apertures of unprecedented size. The R-MXAS system is a single platform comprising a 1-D sparse antenna array on a rigid tether and one or more additional tethered antennas that rotate in a plane orthogonal to the 1-D array.
The processing exploits the interferometric baselines formed between the rotating tethered antenna(s) at radius R and each of the antennas of the 1-D array on the rigid tether. A half-revolution of the rotating antenna(s) engenders a continuum of projected baselines into a horizontal plane which becomes the virtual 2D aperture. Applications of such large apertures, which may span 100’s of meters, include imaging applications such as persistent (GEO-based) RF earth imaging to benefit climate and weather modeling, or mapping of coronal mass ejections (CMEs) from a solar polar orbit to facilitate interplanetary voyages.