ISS and satellite TLE pass sampler
Compute geometric satellite pass samples from two orbital element lines you provide. The built-in ISS example is historical, dated June 2019; it is not a live prediction.
Your inputs
Start with the example values, then replace them with your own. For tables, keep the vertical bar separators and use a dot for decimals.
This simplified educational calculation has stated assumptions. Do not use it for navigation, engineering safety or other safety-critical decisions.
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Result and workspace
Use the start button to open your result or activity.
How it works
Validate line lengths, checksums and catalog identity. Propagate with SGP4/SDP4 through satellite.js 6.0.1 every 30 seconds, rejecting windows more than seven days from the element epoch. Group samples above the chosen elevation. Short passes can be missed and boundaries are sampled; illumination, eclipse, brightness, terrain and weather are not modeled. Use fresh elements from a trusted provider.
Worked example
These sample results use the original example inputs in the form. They do not change when you edit your inputs; your own result appears in the workspace.
- TLE age at window start: 0.509 days
- Geometric pass intervals: 6
| First sampled UTC | Last sampled UTC | Peak sampled UTC | Peak altitude |
|---|---|---|---|
| 2019-06-05T10:49:00.000Z | 2019-06-05T10:53:30.000Z | 2019-06-05T10:51:00.000Z | 18.4723 |
| 2019-06-05T12:24:30.000Z | 2019-06-05T12:30:30.000Z | 2019-06-05T12:27:30.000Z | 49.2063 |
| 2019-06-05T14:03:00.000Z | 2019-06-05T14:07:00.000Z | 2019-06-05T14:05:00.000Z | 15.7826 |
| 2019-06-05T15:41:00.000Z | 2019-06-05T15:44:30.000Z | 2019-06-05T15:42:30.000Z | 14.3102 |
Read the result carefully
Results depend on the values and assumptions shown above. Change one input at a time to see its effect. A blank or unavailable result means the data does not support a calculation; it is not zero.