An improved leak detection system for oil and gas pipelines and the like, including submerged or buried structures, the system including an aerial- or space-based platform with GPS and Attitude Determination and Control System (ADCS) capability, the platform connected to a hyperspectral imaging sensor, the system including processor and memory structured with a vegetative index such that chemical and hydrocarbon leaks are detected within regulatorily-approved time limits based on changes in the vegetative index.