hi - i'm interested in modeling our streetlights as accurately as possible. i have the wattage, est. lumens, lightbulb type, and some other schema information for the approximately 4000 lights in charlottesville. what are the most important factors for understanding how well or poorly lit the sidewalks below these lights are? given the information we have are we in a position to make these determinations? if not what other information should we be gathering to help in our assessments? do we need to know whether the lights are on a hill? how important are those factors or can we estimate that the world is flat (haha)