We compare a variant of Anderson Mixing with the Jacobian-Free Newton-Krylov and Broyden methods applied to an instance of the k-eigenvalue formulation of the linear Boltzmann transport equation. We present evidence that one variant of Anderson Mixing finds solutions in the fewest number of iterations. We examine and strengthen theoretical results of Anderson Mixing applied to linear problems. * Corresponding authorEmail addresses: mcalef@lanl.gov (Matthew T. Calef), efichtl@lanl.gov (Erin D. Fichtl), warsa@lanl.gov (James S. Warsa), berndt@lanl.gov (Markus Berndt), nnc@lanl.gov (Neil N. Carlson)

Configurations of N points on the two-sphere that are stable with respect to the Riesz senergy have a structure that is largely hexagonal. These stable configurations differ from the configurations with the lowest reported N-point s-energy in the location and structure of defects within this hexagonal structure. These differences in energy between the stable and minimal configuration suggest that energy scale at which defects play a role. This work uses numerical experiments to report this difference as a function of N, allowing us to infer the energy scale at which defects play a role. This work is presented in the context of established estimates for the minimal N-point energy, and in particular we identify terms in these estimates that likely reflect defect structure.

We describe an efficient and cost-effective data access mechanism for Sentinel-1 Terrain Observation with Progressive Scans (TOPS) mode bursts. Our data access mechanism enables burst-based data access and processing, thereby eliminating the European Space Agency’s (ESA’s) Sentinel-1 Single Look Complex (SLC) data packaging conventions as a bottleneck to large scale processing. The pipeline throughput is now determined by the available computation resources and the efficiency of the analysis algorithms. For targeted infrastructure monitoring studies, we are able to generate coregistered, geocoded stacks of SLCs for any area of interest (AOI) in the world, in a few minutes. In addition, we describe our global scale radar backscatter and interferometric products, and associated pipeline design decisions that ensure geolocation consistency across the suite of derived products from Sentinel-1 data. Finally, we discuss the benefits and limitations of working with geocoded SLC data.