Reference

Investigators use a combination of technologies and methods to determine the location, height, and speed of an aircraft. Here's how they do it:

1. Air Speed Indicator (ASI): This instrument uses the aircraft's pitot-static system to compare pitot and static pressure, thereby determining the forward speed of the aircraft. Air Speed Indicator | SKYbrary Aviation Safety

2. Altimeter: Aircraft measure barometric altitude using their altimeter, which is essentially a pressure-based instrument that measures the air pressure outside. Understanding altitude on Flightradar24

3. Photogrammetry: This technique uses photographs or video frames to measure height and distance. It's a science that can establish the exact position and height of objects, such as an aircraft. How Video Forensic Experts Determine Height in Images and Videos

4. Trigonometry: Trigonometry is crucial in aviation for calculating climb angle, flight path, distance traveled, and descent angle. The Trigonometry of Aviation. By: Xan Conconi - Medium

5. Radar: Radar systems use radio waves to determine the distance, direction (azimuth and elevation angles), and radial velocity of objects, including aircraft. Radar - Wikipedia

These methods are often used in combination to provide a comprehensive understanding of an aircraft's position, height, and speed.