Experimental program on electromagnetic propagation in random structures. Observation of photon localization in the near future is a specific goal. Approaches include the use of both light and microwave radiation. The cross-correlation of fluctuations in intensity will be measured as a function of separation between two points. The physical systems which are employed in the experiments consist of metallic or high-index dielectric spheres imbedded in a transparant medium. Measurements will be made in the diffusive, critical, and localized regimes.