Unmixing the Materials and Mechanics Contributions in Non-resolved Object Signatures

摘要

Temporal behavior of a non-resolved resident space object (RSO) signature is a function of the abundance of its contributing materials. These abundances are, in turn, a function of the orbital behavior of the RSO. For example, in case of a spin-stabilized RSO, the abundances display a cyclic behavior. The present work uses a positive matrix factorization technique to extract the temporal variation of material abundances from hyperspectral or multi-spectral time-resolved signatures. A Fourier analysis of temporal variation of material abundance provides knowledge about the mechanics of the space object. This paper describes the unmixing and Fourier analysis process that, taken together, extract information about materials and mechanics from non-resolved RSO signatures. Unmixing results are presented for simulated hyperspectral signatures and for three- or four-color Johnson BVRI photometry observations data. These two situations cover the range of optics and sensor capabilities that may be available from a premier site for optical observations to a commercial-off-the-shelf small-aperture telescope site.