Aviation utilizes multiple types of altitude (e.g., barometric, radar, GPS), each derived from different measurement principles and reference datums. Barometric altimeters, which measure air pressure, ...

Mechanical altimeters, despite their ingenious design, are susceptible to various instrument errors including mechanical wear, scale inaccuracies, installation/position effects, and hysteresis, which ...

Here's a neat little app that uses a little-known function of the Apple iPhone: Barometer. It can be found for free in the Apple Store. There are additional features for purchase, but the free version ...