Role
Developer and author
Randolph Tavenner is the author behind Sea Level. He writes about how elevation is computed, where the numbers come from, and why the app stays small and private. Questions land in a real inbox and get a real answer.
5 posts
Three absences, stated and designed in: nothing to sign up for, nothing to display, nothing to track. What the app stores, what it sends, and why the privacy is fixed by design instead of by settings.
The global model behind the 70-meter map is computed in meters, most of the world reads them in meters, and the parts that do not still expect feet. How the switch works, and why it never changes the calculation.
The optional elevation-warning feature does background work only while you are near a risky elevation, in sessions that shut themselves down. How the 2-hour sessions are designed, and what happens to the battery.
What the full-melt scenario is, how the number is estimated, and what the map does and does not predict. The assumptions behind Sea Level's headline number, stated plainly.
Sea Level does not guess: it combines GPS, a barometer when the phone has one, and public elevation data as the fallback. How the three sources work, how they rank, and where the meters come from.