A very specialized and interesting term.

In the context of aviation and aerospace, "Accumulated Doppler Range" refers to a technique used in radar and navigation systems to determine the distance of an aircraft or spacecraft from a reference point, typically the ground or a satellite.

Here's a breakdown of the concept:

1. Doppler Shift: When an aircraft or spacecraft is moving relative to a radar system or a navigation satellite, the frequency of the signal transmitted by the radar or satellite is shifted due to the Doppler effect. This shift is proportional to the velocity of the aircraft or spacecraft.
2. Range Measurement: By measuring the Doppler shift, the radar or navigation system can estimate the velocity of the aircraft or spacecraft. However, to determine the distance (range) of the aircraft or spacecraft, additional processing is required.
3. Accumulated Doppler Range: This technique involves integrating (accumulating) the Doppler shifts measured over a period of time to calculate the distance traveled by the aircraft or spacecraft. The accumulated Doppler shifts are used to estimate the range, taking into account the velocity and acceleration of the vehicle.

The Accumulated Doppler Range technique is used in various aviation and aerospace applications, including:

• Radar systems for air traffic control and surveillance
• Navigation systems, such as GPS and GLONASS
• Spacecraft navigation and orbit determination
• Missile guidance systems

By using the Accumulated Doppler Range technique, these systems can provide accurate range measurements, even in the presence of noise, interference, or limited visibility.

I hope this explanation helps you understand this complex concept!