True Altitude is described as which of the following?

True altitude refers to the vertical distance of an object above mean sea level (MSL). This measurement is crucial for various aviation and navigation purposes, as it gives pilots an accurate reference point from which to measure the altitude of their aircraft in relation to sea level, which is a standard reference. It ensures consistent communication among pilots, air traffic control, and aviation charts.

Mean sea level serves as a baseline for aviation, allowing for safe altitude separation among aircraft flying in the same airspace. Understanding true altitude is vital for maintaining safe distances between airborne vehicles and avoiding terrain collisions, especially in mountainous areas where local ground elevation can vary significantly.

The other options focus on measurements that are not aligned with the standard definition of true altitude. Height above ground level pertains to the distance between the aircraft and the ground directly beneath it, which can vary widely and is not a fixed reference like sea level. The total distance from the ground is ambiguous and lacks specificity, while the calculated height during a flight may refer to various types of altitudes depending on aircraft instruments, but does not define true altitude specifically.