The shear modulus information is measured for sparse locations in a scanning field of view. The quick connect power take-off assembly includes a housing, a driving assembly that is fixedly mounted to the ATV, a driven assembly that is releasably connected to the driving assembly, and either directly to an implement or to a power transfer assembly. The quality metric may be used, for example, to determine which keyframe to use to make a thumbnail to represent video data. The first genetic crop is planted at a first crop spacing and at a first row spacing that is beneficial to yielding trees with high lumber value. This makes it possible to efficiently execute the program in synchronization with reproduction of AV data or the like.