“…DIRSIG performs ray-tracing calculations of "light" emanating from realistic models of electromagnetic sources (e.g., sun, moon), reflecting off of virtual 3-D objects composed of various materials, and arriving at a virtual imaging detector with a specific array size and optical field of view. Coregistered detector "channels" can be specified to output [5]. Alternatively, channels can be designed to output spectral radiance that has passed through ideal linear polarizers oriented at several angles (e.g., 0 , 45 , 90 , & 135 ) to mirror the operation of an imaging polarimeter, and combined into Stokes vector imagery via equation 1 assuming negligible circular polarization (i.e., L ,3 0).…”