What does AGL mean in AMATEUR RADIO

Definition

AGL stands for Above Ground Level and refers to the altitude or elevation of an object with respect to a fixed elevation datum on the earth's surface. This can refer to any point of interest, from a mountain summit or tower peak, all the way down to ground level itself. In addition, AGL measurements are not relative to sea level but rather they are dependent upon the local datum established at any given location. This means that AGL measurements may differ considerably as one travels from one location to another.

Uses

AGL is beneficial for navigation and surveying operations where it's important to determine exact altitudes and elevations quickly and accurately. The term is commonly used in aviation where aircraft maintainers use it when troubleshooting aircraft performance issues, mapping flight paths and ensuring safe take-offs and landings by avoiding terrain obstacles like hills or buildings. Similarly, meteorologists use AGL when predicting weather events such as rain showers or thunderstorms due to changes in air pressure at different altitudes/elevations.