analyze experimental data from Rayleigh-Benard convection in a large aspect ratio cell using a new, efficient method applicable to disordered striped patterns from biological, chemical, optical, and fluid systems. We present statistics of various local pattern properties such as the local wave-vector magnitude, local pattern orientation, and defect densities. Using these statistics, we provide quantitative evidence demonstrating that the stability boundaries derived for infinite systems are applicable to local patches within disordered patterns. We also present the first experimental observation of multiple length scales within spiral defect chaos.