Ground Risk Assessment of UAV Operations Based on Horizontal Distance Estimation under Uncertain Conditions

Table 2

Percentage of different types of areas and central angles

Zone no.	Buildings	Trees (%)	Sparse tree (%)	No obstacles (%)	Central angle (°)
Zone 1	17.32%	21.37	23.74	37.57	78.0
Zone 2	0	58.32	32.39	9.29	26.2
Zone 3	27.27%	49.69	5.81	17.23	88.7
Zone 4	0	41.95	21.10	36.95	23.6
Zone 5	11.14%	46.45	6.68	35.73	87.0
Zone 6	0	7.69	62.03	30.28	56.5