Ground Station Pass Duration Calculator

Visible pass time from orbit altitude and station latitude.

Orbital altitude (km)

Min elevation angle (deg)

Station latitude (deg)

Downlink data rate (Mbps)

Tab to move between fields

Max pass duration (min)

7.94

Passes per day

Data per day (MB)

3,871.4

Avg pass duration (min)5.16

Orbital period (min)95.5

Revolutions per day15.04

Coverage radius (deg)14.97

Data per max pass (MB)2,978

Cos Rho0.39

Sin Elev Plus Rho0.97

How to Use This Calculator

Enter orbital altitude (km) and minimum usable elevation angle (degrees, typically 5–15°).
Set your ground station latitude (degrees) and downlink data rate (Mbps).
Review maximum and average pass duration (min), passes per day, and orbital period.
Use data downlinked per pass (GB) to verify the ground station can receive all mission data.
Multiple ground stations significantly increase daily contact time — model each station separately.

How the result changes with Orbital altitude (km)

Orbital altitude (km)	Max pass duration (min)	Passes per day	Data per day (MB)
5,135	53.4	3	39,050
17,598	221.67	1	54,032
32,553	500.47	1	121,990.1
45,015	783.43	1	190,960.2

Orbital altitude (km): Circular orbit altitude above Earth's surface in kilometers.
Min elevation angle (deg): Minimum elevation above the local horizon for a usable pass. Higher = shorter but better quality passes.
Station latitude (deg): Ground station geographic latitude in degrees (absolute value).
Downlink data rate (Mbps): Effective downlink data rate for computing data volume per pass.

Max pass duration (min): Duration of a best-case overhead pass.
Avg pass duration (min): Typical average pass (~65% of maximum).
Passes per day: Estimated visible passes per day from this ground station.
Orbital period (min): Time for one complete orbit.
Revolutions per day: Number of orbits completed in a sidereal day.
Coverage radius (deg): Ground footprint half-angle from the sub-satellite point.
Data per max pass (MB): Maximum data volume downloadable in one best-case pass.
Data per day (MB): Estimated total daily download volume.

Identify Input Parameters
4 parameters
Orbital altitude (km) = 550, Min elevation angle (deg) = 10, Station latitude (deg) = 40, Downlink data rate (Mbps) = 50 = 4 input(s) provided
Calculate Max pass duration
Max pass duration = maxPassDurationSec / 60
7.94 = 7.94
Calculate Passes per day
Passes per day
2 = 2
Calculate Data per day
Data per day = dataRateMbps * avgPassDurationMin * 60 * passesPerDay / 8
3871.4 = 3871.4
Calculate Avg pass duration
Avg pass duration = maxPassDurationMin * 0.65
5.16 = 5.16
Calculate Orbital period
Orbital period = periodSec / 60
95.5 = 95.5