Patent ID: 8327838

Claim:
A method for verifying alignment of a parabolic trough reflector and its receiver pipe in a solar thermal field for collecting sunlight energy, the parabolic trough reflector having a sun-receiver-vertices plane, the method comprising: acquiring an aerial image of the parabolic trough reflector from above the thermal field while passing through the sun-receiver-vertices plane of the parabolic trough reflector; analyzing the aerial image and determining whether any reflection of sunlight leaking past the receiver pipe is visible in the parabolic trough reflector in the aerial image, whereby a presence of a visible reflection of sunlight leaking past the receiver pipe in the parabolic trough reflector in the aerial image denotes that the parabolic trough reflector and its receiver pipe are out of alignment; and adjusting the alignment of the parabolic trough reflector and its receiver pipe when a determination is made that the parabolic trough reflector and its receiver pipe are out of alignment.