Satellite Ground Speed Calculator

Calculator Inputs

Calculation Mode

Choose a derived or direct method.

Orbit Preset

Presets fill altitude and inclination.

Altitude Above Earth (km)

Used for orbital radius and speed.

Inclination (degrees)

0° is equatorial. 90° is polar.

Subpoint Latitude (degrees)

Local Earth rotation depends on latitude.

Manual Orbital Speed (km/s)

Used only in manual mode.

Ground Distance (km)

Used only in direct mode.

Elapsed Time

Enter the numeric time amount.

Time Unit

Used only in direct mode.

Include Earth rotation adjustment

Unchecked mode removes the surface rotation term.

Plotly Graph

This curve shows approximate ground speed against altitude for the selected inclination and latitude.

Inclination 53° | Latitude 0°

Example Data Table

These examples use the same approximate model shown in the formula section.

Case	Altitude (km)	Inclination (°)	Latitude (°)	Ground Speed (km/s)	Ground Speed (km/h)	Period (min)
ISS-like LEO	42	51.6	0	6.90492	24,857.72	92.97
Sun-synchronous	7	98	30	6.82986	24,587.48	98.77
Navigation MEO	20,2	55	20	0.7673	2,762.29	718.7

Formula Used

1. Orbital speed for a circular orbit

v_orbit = √(μ / (R_E + h))

2. Surface-projected speed

v_projected = v_orbit × R_E / (R_E + h)

3. Local Earth rotation speed

v_rotation = ω_E × R_E × cos(φ)

4. Approximate ground speed

v_ground ≈ √(v_projected² + v_rotation² − 2v_projected v_rotation cos(i))

5. Direct mode

v = d / t

This page uses an approximate circular-orbit model. It is useful for planning, estimates, and comparisons, but it is not a full propagator.

How to Use This Calculator

Select a calculation mode.
Pick a preset or enter your own orbital inputs.
Set altitude, inclination, and subpoint latitude.
Enable or disable Earth rotation adjustment.
Click Calculate to show results above the form.
Review ground speed, period, and related outputs.
Use the CSV or PDF buttons to export results.
Inspect the Plotly graph to compare altitude trends.

Frequently Asked Questions

1. What is satellite ground speed?

Satellite ground speed is the apparent speed of the satellite’s subpoint moving across Earth’s surface. It differs from orbital speed because altitude and Earth rotation change the surface track.

2. Why is ground speed lower than orbital speed?

Orbital speed is measured at the satellite’s altitude. Ground speed is projected onto Earth’s surface, so the smaller surface radius reduces the apparent track speed.

3. Why does latitude matter here?

Earth’s surface rotates fastest at the equator and slows toward the poles. That changes the local rotational contribution used in the ground-speed estimate.

4. What does inclination change?

Inclination changes how the orbit aligns with Earth’s rotation. Prograde and retrograde tracks combine differently with the surface rotation term, which changes the estimated ground speed.

5. When should I use direct mode?

Use direct mode when you already know the surface distance and elapsed time. It is useful for checking measured data, image swaths, or mission reports.

6. Is this suitable for geostationary satellites?

Yes, for rough comparisons. A true geostationary satellite should show a very small apparent ground speed near the equator in an ideal circular case.

7. Does this include drag, oblateness, or perturbations?

No. This is a simplified circular-orbit estimate. It does not model drag, J2 effects, eccentricity, station keeping, or detailed propagation physics.

8. Can I export the results?

Yes. After calculation, use the CSV button for tabular data or the PDF button for a shareable report snapshot of the result section.