Systems and methods for detecting an obstruction in a detector surface fields are provided. In one respect, a set of lines may be projected over substantially a half of the detection area and may subsequently imaged and evaluated. Other embodiments may include a second set of lines that may be projected over substantially a second half of the detection area and may subsequently imaged and evaluated. The images may be evaluated to determine if there are breaks (e.g., an obstruction) in the projected set of lines. Based on the evaluation, the detector may provide dynamic feedback signals to a processor, which may adjust the position of the detector or provide a signal indicating an obstruction.