Extended source imaging using a single rotating modulation collimator

Rotating modulation collimators (RMC) have traditionally been most sensitive for locating point sources, but have also been used for imaging time dependent extended sources such as solar flares. Current methods for RMC imaging of extended sources have relied upon multiple RMC systems each with their own detectors, electronics, and mask sets. The difference between systems is that each mask pair has a different set of slit spacings so that different spatial frequency components of the source field can be recorded. The data from the ensemble of RMCs is then combined to produce the final extended source image. This research considers a different approach for imaging extended sources with an RMC. This method relies on a single RMC system, and takes advantage of the fact that for terrestrial imaging the separation between masks is an easily changeable and free parameter. Changing the separation between the masks effectively represents changing the spatial frequency over which the RMC is most sensitive. By measuring multiple data sets with different values of the mask separation parameter, a more complete map of the frequency domain can be recorded. This data is then used with a maximum likelihood expectation maximization algorithm to generate the final image.