Definition
In radar and terrain-display systems, raw terrain is the unprocessed elevation data of the ground beneath and ahead of an aircraft, presented exactly as the sensor or database returns it without filtering, smoothing, or threat-based color coding.
Plain English
It's the ground shown on a display in its plain form -- just the actual heights of hills, mountains, and valleys, without any system enhancements or warnings layered on top.
Context Anchor
Seen in terrain-clearance, charting, survey, and landing-site discussions.
Derivation
Raw' here carries its common meaning of 'unprocessed' or 'in its original state' -- the same sense as raw data or raw footage. It signals that no system has interpreted the information yet.
Why Pilots Care
Raw terrain often contains hidden obstacles, slopes, or soft surfaces that can damage the aircraft or cause loss of control during a forced landing.
Analogy
Raw terrain is like an unedited photo: it shows what was captured before anyone improves, smooths, or marks it up for easier use.
Intuition Check
Raw does not mean rough or dangerous here. It means unprocessed: the terrain as measured before smoothing or added safety clearance.
Example Sentence 1
The display can be switched to show raw terrain, giving the crew a direct view of ground elevation without the system's threat coloring.
Example Sentence 2
Raw terrain near the river looked flat from the air but proved too soft once the wheels touched.