Environmental monitoring is a vital step towards predicting and responding to natural disasters, conserving wildlife, beginning to understand global environmental dynamics and tackling pollution. Due to the nature and scale of such observation tasks, extensive research is alluded to environmental monitoring using multi-agent robotic systems. For a large proportion of these problems, an aerial solution is useful as they offer wider fields of view, full control in three dimensions, and can take paths free of any obstacles. Moreover, multiple UAVs working collectively on goals can make a mission more reliable, cut down operation time, and make a system much more fault tolerant.