Table 3.

Comparison of constellation model Characteristics.

Parameter	Polar orbit constellation	Walker constellation	OCO constellation
Typical Inclination	85°–90°	40°–60°	0°
Coverage Characteristics	Dense coverage at high latitudes	Uniform global coverage	Belt-shaped coverage along the equator
Single-Satellite Coverage Half-Angle θ	26.9° (h = 500 km)	22.4° (h = 1600 km)	34.7° (h = 1600 km)
Minimum Visible Satellites	3 (latitude > 80°)	5 (global)	8 (latitude ± 20°)
Applicable Missions	Polar monitoring, meteorological remote sensing	Navigation enhancement, global communications	Equatorial communications, disaster early warning