What is Altitude?
Altitude is a measure of the vertical distance between a reference datum and some point/object. The specified datum varies according to context. For instance, in geography, altitude can be used to describe the height above sea level (although the term “elevation” is preferred).
Why is Altitude important?
Altitude is important in several fields, particularly aviation, meteorology and atmospheric studies. Earth's atmosphere is divided into several regions based on altitude. These regions, also commonly called “atmospheric layers” start and finish at varying altitudes depending on the season and distance from the poles. The Kármán line, at an altitude of 100 kilometres (62 mi) above sea level, is the commonly described border between the atmosphere and space. The altitudes that define some of the atmospheric layers do exceed this border, however.
Altitude, in the context of meteorology and atmospheric studies share relationships with both Atmospheric Pressure and temperature and, therefore, humidity. Due to the different properties of the atmospheric layers (divided by altitude) ultraviolet radiation also relates to altitude.
How is altitude measured?
Altitude is typically measured using an altimeter. It is important to note, particularly in aviation, that there are various meaning attached to altitude, and thus each is given a modifier (e.g. True altitude). The different “types” of aviation altitude are described simply below:
- Indicated altitude – the altitude shown on the altimeter.
- Absolute altitude – altitude in terms of the distance above the ground directly below
- True altitude – altitude in terms of elevation above sea level
- Height – altitude in terms of the distance above a certain point
- Pressure altitude – the air pressure in terms of altitude in the International Standard Atmosphere
- Density altitude – the density of the air in terms of altitude in the International Standard Atmosphere in the air
In the case of ☒CHIPS, altitude can be measured, displayed and recorded instead of atmospheric pressure by the advanced weather sensor on the SW01 ☒CHIP.