How does command guidance send steering instructions to a missile?

In command guidance, steering instructions are sent to a missile by tracking the projectile from a launch site or platform and transmitting control commands through various mediums, including radio, radar, laser impulses, thin wires, or optical fibers.1

The process typically involves the following methods:

• Tracking: The target and the missile are monitored using radar, optical instruments, or television imagery relayed from the missile itself.1
• Command Generation: Control systems at the launch site—often automated by computers—calculate the necessary trajectory to intercept the target.1
• Transmission: These calculated steering commands are sent to the missile to adjust its flight path.1
• Specialized Techniques:
  • Beam Riding: The missile senses a radar or laser beam pointed at the target and automatically corrects its course to stay within that beam.1
  • Track-via-Missile: A radar unit inside the missile tracks the target and sends relative bearing and velocity data back to the launch site, where computers determine the optimal intercept path and transmit the final commands back to the missile.1

These systems ensure that the missile remains on an accurate course toward its target throughout its flight.12