Adaptive servo tracking

This paper describes a self-adaptive sampled-data radar tracking loop. The adaptive tracking loop may be considered to be a low-pass filter with a variable bandwidth. The loop is designed to adapt rapidly to changes in the input signal by monitoring both the apparent error and the loop output. Results show a mean tracking accuracy 25 to 34 per cent higher than that of a comparable linear system at a receiver SNR of 10 db. In other terms, to attain the same accuracy the comparable linear system requires a SNR of 13 db. This improvement in performance is obtained with relatively little additional circuitry. In general, the degree of improvement obtained by adaptive tracking will depend on the compromises made in the design of the unadapted loop to track the most difficult type of target.