Abstract: A variable length vector display system allows visual indication of the sd and direction of aircraft or moving vehicles, maintaining a constant illumination on the face of a cathode ray tube independent of the vector length or vector movement. The vector length from the target vehicle coordinate points to the predicted intercept coordinate points are displayed. Voltages defining the origin and the end point of a vector to be displayed are coupled through respective comparator and arithmetic units, scaled to provide a deflection factor, multiplied, and coupled through respective controlled integrator circuits. The integrators are controlled by a variable gate which operates as a function of the input signal, thereby varying the on-off time of the integrators for simultaneous operation. Output signals from the integrator circuits are coupled to respective X and Y deflection circuits of a cathode ray tube load.