Planet and local obstruction comparison
Compare a planet track with a skyline you measured, so a geometric rise does not get confused with clearing a building or hill.
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.
Never look at the Sun through a telescope or binoculars without correctly fitted specialist solar equipment. These calculations do not establish safe equipment use.
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Result and workspace
Use the start button to open your result or activity.
How it works
Interpolate the entered skyline linearly and cyclically in azimuth, then subtract it from the body altitude at half-hour UTC samples. Positive clearance means above the modeled obstacle, not visible through cloud or safe to observe. Sparse skyline points can miss narrow obstructions.
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.
- Clear samples above entered horizon: 22
| UTC instant | Body altitude | Azimuth | Obstacle altitude | Angular clearance |
|---|---|---|---|---|
| 2026-10-08T00:00:00.000Z | 4.3558 | 73.5241 | 18.1693 | -13.8135 |
| 2026-10-08T00:30:00.000Z | 9.7645 | 78.2937 | 18.6993 | -8.9348 |
| 2026-10-08T01:00:00.000Z | 15.3268 | 83.0273 | 19.2253 | -3.8984 |
| 2026-10-08T01:30:00.000Z | 20.9623 | 87.8167 | 19.7574 | 1.2048 |
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.