Radar power multiplier for acquisition of low observables using an ESA radar

In this paper the acquisition of a low observable (LO) incoming tactical ba llistic missile using the measurements from a surface based electronically scanned array (ESA) radar is presented. We present a batch maximum likeliho od (ML) estimator to acquire the missile while it is exo-atmospheric. The p roposed estimator, which combines ML estimation with the probabilistic data association (PDA) approach resulting in the ML-PDA algorithm to handle fal se alarms, also uses target features, The use of features facilitates targe t acquisition under low signal-to-noise ratio (SNR) conditions. Typically, ESA radars operate at 13-20 dB, whereas the new estimator is shown to be ef fective even at 4 dB SNR tin a resolution cell, at the end of the signal pr ocessing chain) for a Swerling III fluctuating target, which represents a s ignificant counter-stealth capability. That is, this algorithm acts as an e ffective "power multiplier" for the radar by about an order of magnitude. A n approximate Cramer-Rao lower bound (CRLB), quantifying the attainable est imation accuracies and shown to be met by the proposed estimator, is derive d as well.