Abstract: Systems and methods are disclosed to construct subsurface images from diffuse seismic energy. Various disclosed system embodiments include multiple seismic sensors that each convert received seismic energy into one or more seismic signals. One or more processor combine the seismic signals to determine a subsurface map. As part of determining the map, the processor(s) systematically focus the array of seismic sensors on each bin in the subsurface volume of interest. In this manner each bin becomes a focal point of the array. For each bin, the processor(s) analyze the seismic wave travel time to each seismic sensor and apply a corresponding time shift to align the seismic signals with a uniform travel time. The time-shifted seismic signals are then combined to determine an intensity value for seismic energy radiating from the focal point. A subsurface map can then be derived from the intensity value as a function of position.

Abstract: There is provided an apparatus and vehicle for laying seismic line cable on the ground, retrieving the cable from near the ground surface, and transporting the cable. The vehicle carries at least one cable reel for unspooling the cable therefrom when laying cable and spooling the cable thereon when retrieving the cable. When laying cable, a towed depression wheel forms a depression wheel forms a channel in the ground for laying the unspooled cable therein. The cable reel includes an electric slip ring for electrically energizing and testing the cable components while the cable is being laid. When used in very cold environments, a temperature controlled enclosure encloses the cable reel for maintaining the cable at a temperature at which it is sufficiently flexible for handling and laying. When retrieving cable, a motor power controller automatically controls the power to the cable reel drive motor for maintaining constant tension in the cable being retrieved.