What is the most accurate type of guidance system for a missile and how does it work?

Question

I've been reading about missile technology and came across various types of guidance systems. I'm particularly curious about which one is considered the most accurate. Can someone explain what is the most accurate type of guidance system for a missile and how does it work? I'd also love to know about the technology behind it and any examples of missiles that use this guidance system.

Hannah Walker · Accepted Answer

The accuracy of missile guidance systems can be categorized into several types, each with its own advantages and disadvantages. Here’s a detailed breakdown: Inertial Navigation System (INS): This system uses a combination of accelerometers and gyroscopes to calculate the missile's position based on its initial launch coordinates. INS is highly accurate in the short term, but its accuracy can degrade over time due to drift. Global Positioning System (GPS): GPS provides real-time location data by receiving signals from satellites. When combined with INS, GPS can correct any drift in the inertial navigation system, significantly enhancing accuracy. This hybrid system is widely used in modern cruise missiles. Terminal Guidance Systems: These systems come into play during the final phase of the missile's flight. They can include radar homing, infrared homing, or laser guidance, allowing the missile to adjust its trajectory based on real-time data from its target. Active Radar Homing: This method involves the missile emitting radar signals to detect and home in on targets. It is particularly effective for air-to-air and surface-to-air missiles. Passive Infrared Homing: This system detects the heat emitted by a target, allowing the missile to track and engage without needing to emit signals that could reveal its position. In summary, the integration of INS and GPS is often regarded as the most accurate guidance system for missiles. This combination allows for high precision in targeting, especially when complemented by terminal guidance systems for final adjustments. Examples of missiles utilizing this technology include the Tomahawk cruise missile and various modern ballistic missiles.