Final answer:
The radar altimeter scale on a VSD typically disappears when an aircraft exceeds the maximum operational range of the radar altimeter, which is around 2,500 to 5,000 feet. Air density changes with altitude are unrelated to radar altimeter function, and the resolution of space-probe radar images like Magellan's indicates the capability of radar tech rather than aircraft altitude readings.
Step-by-step explanation:
The altitude at which the radar altimeter scale on the VSD (Vertical Situation Display) will disappear varies depending on the specific system and aircraft configuration.
However, generally, the altimeter scale may disappear when the aircraft is above the range of the radar altimeter, typically above 2,500 feet (762 meters) to 5,000 feet (1,524 meters). Commercial airliners and other aircraft equipped with such systems use radar altimeters for lower-altitude operation to assist with safe terrain clearance and approaches during flight.
Focusing on the data provided regarding changes in air density with altitude, it is important to note that these changes do not directly correlate to the operation of the radar altimeter. Instead, these changes are more relevant to considerations in aerodynamics and engine performance at different altitudes. The decrease in air density by approximately 0.1 kilograms/cubic meter for every additional 1,000 meters of altitude, as calculated from the given points at altitudes of 4,000 meters and 6,000 meters, is an interesting observation, but not necessarily related to the function of radar altimeters, which are focused on measuring the distance from the aircraft to the ground or sea level using radar waves, rather than atmospheric density.
Lastly, Magellan's resolution of 100 meters showcases the potential precision of radar imaging technology, but this is more relevant to the resolution of images from space probes than the functioning of radar altimeters used in aviation which are focused on providing accurate altitude data.