It states that other tall objects could be used, in addition to street lights:
"The system could also be installed on other existing structures such as cell towers, church steeples, office buildings, parking decks, radio towers, telephone/electrical poles and other vertical structures," reads the patent.
It sounds feasible and quite practical. I just have one question. What does the drone do when it approaches a street light for landing only to find a pelican already resting?