Notes on Missile Guidance System

Key Concepts

• Missile Position Awareness:

  • The missile is aware of its position at all times because it calculates where it is by knowing where it isn't.
  • By subtracting its current position from the position it isn't occupying, it determines a deviation.

• Guidance Subsystem:

  • Utilizes deviations to create corrective commands.
  • These commands redirect the missile from its current position to the intended position.

Position Correction Process

• Position Transition:

  • The missile moves from a position where it is to a position where it isn't.
  • Upon reaching the new position, the previous position becomes the position where it isn't.

• Position Variation:

  • If the missile's current position is not the previous unoccupied position, a variation is identified.
  • Variation represents the discrepancy between the current and previous intended positions.

• Significance of Variation:

  • Considered significant if it affects the missile's trajectory.
  • The Guidance and Autopilot Assembly (GAA) may correct significant variations.

Error Calculation

• Missile's Historical Position Awareness:

  • The missile knows its previous positions to compute deviations.

• Error Determination Process:

  • Subtracts its intended position from an unoccupied position.
  • Differentiates this from the algebraic sum of undesired and previous positions.
  • The result is the deviation and its variation, termed as error.