EarthCurve: Horizon Calculator

TipTinker

Contains adsIn-app purchases

About this app

EarthCurve turns your eye height, the target's height, and the distance into the hidden height, horizon distance, and a clear cross-section diagram.

• See how much of a ship, island, tower, or shoreline is hidden, and whether it is fully visible, partly hidden, or out of sight
• Get the horizon distance and the farthest range at which the target's top still shows
• Solve it backwards: the lowest eye height that shows a target, or the farthest distance at which it still appears
• Choose the atmosphere model: pure geometry, standard 7/6 R, geodetic k = 0.13, radar 4/3 R, or your own refraction coefficient
• Pick eye heights for seated, standing, boat deck, building, cliff, or tower
• Compare hidden height across a ladder of nearby distances and copy a full distance table for a spreadsheet
• Switch between metric, imperial, and nautical units without changing the sighting
• Save sightings you check often and share a result as text

What’s new

Performance improvements and bug fixes