**2. Methods**

For the present work, a systematic review research methodology was adopted. In that context, a range of platforms was sourced for information. Most of the sources cited in this survey were found in (a) the IEEE Xplore digital library, (b) the Google scholar platform, (c) the online Elsevier platform, and d) the online MDPI platform.

Keywords utilized were: "Coverage Path Planning", "Decomposition methods", "CPP methods", "Multi-robot CPP methods", "Cell decomposition", "Unmanned Aerial Vehicles", "Energy optimal path", "Energy-aware approaches", "Multi-robot systems", "Robot coverage", "Robot kinematics", and "UAV Remote Sensing". Initially, the resulting papers (approximately 170) were filtered by choosing the ones referring to CPP algorithms, decomposition methods, multi-robots and multi-UAV coverage path strategies, and energyawareness CPP algorithms.

The 170 aforementioned publications reviewed for the decomposition methods, single or multi-robot CPP strategies, multi-UAV CPP methods, and UAV energy-saving algorithms. From the 170 papers, 128 were classified according to the relevance of the survey's scope and their overlapping information. In the end, 128 papers were analyzed for their approaches and their correlation to categorize in sub-sections of decomposition methods, CPP methods, and energy-saving algorithm, of which 88 made it into the refined version of the present survey.
