Zhou Yi-yu

Unbiased converted measurements for tracking

The exact compensation for the bias in the classical polar-to-Cartesian conversion is shown to be multiplicative and to depend on the statistics of the cosine of the angle measurement errors. An unbiased conversion is presented. A comparison between this unbiased conversion and the previously presented debiased conversion is made. The unbiased spherical-to-Cartesian conversion is also presented and evaluated.

Passive location using time of arrival along with direction of arrival and its changing rate

Passive location is a widely investigated problem. In this paper, a pseudo-linear algorithm for moving emitters passive location and tracking based on time of arrival (TOA), direction of arrival (DOA) and DOA changing rate measurements by a non-moving observer is given. This algorithm has high convergence speed and stability, so it is of great practicability. The observability conditions of location and tracking for moving emitters using TOA and DOA measurements are analyzed. Finally, the computer simulation results are presented.

Maneuvering emitter tracking by a single observer using IMM algorithm based on unscented transformation

The unscented transformation (UT) based interacting multiple model (IMM) algorithm is explored to handle maneuvering emitter tracking by a single passive observer, which processes Doppler frequency changing rate and angle measurements concurrently, thus the observer maneuver is not required. Computer simulations are performed to compare the unscented Kalman filter-interacting multiple model (UKF-IMM) estimator with the traditional extended Kalman filter-interacting multiple model (EKF-IMM) estimator. Simulation results reveal that the UKF-IMM estimator is more stable and effective

The question and developing direction of the radar system vulnerability to ECM (RSVECM)

At present, the feasible and pressing task is to adequately make use of the limited actual data of and human beings limited knowledge on the fight mechanism of radar system vulnerability to ECM (RSVECM) to obtain a better rather than a best solution or objective function to RSVECM directly with the aggregation method. That is, the turning point of the dominance of utilizing the electromagnetic spectrum, and the basic index of radar anti-ECM is the relative improvement factor (RIF) which is determined mainly by the statistical result of computer dynamic course simulation.

Unbiased converted measurements for target tracking

The accurate debiasing processing for the bias in the classical conversion mainly depends on the first and second statistics of the cosine of the bearing measurement errors. An unbiased conversion is presented in this paper. Some comparison between the new unbiased conversion with the previously offered debiased conversion is made.

Observability analysis of single passive observer

In this paper observability of single passive observer for target motion slate estimation is discussed. Passive observation systems are divided into bearing, time of arrival, Doppler, bearing and time of arrival, bearing and Doppler observation systems. For every type of systems, observability is analyzed in common observation model. The approximate equivalent relation in systems between time difference of arrival and Doppler is shown by comparing their observability degrees.

A frequency-based inter/intra partly coherent jamming style to SAR

This work is concerned with developing the frequency-based jamming technology against SAR. Firstly, the shift frequency jamming to LFM radar and SAR is analyzed. Then a modified shift frequency jamming to SAR, stepped shift frequency jamming (SSFJ), is presented and discussed. The theoretic research and simulation show that the SSFJ is inter/intra partly coherent with the SAR system and has a region imaging output for protecting the distributed targets. Its jamming power is much less than other jamming styles such as noise jamming, random shift frequency jamming and etc.

Angle-of-arrival estimation based on weighted cyclic spectrum

For cyclostationary signals, a generalized sensor array data model is presented and a new angle-of-arrival (AOA) estimation method based on weighted cyclic spectrum - GSC-SSF is developed in this paper. The proposed algorithm is more convenient and effective in forming the data matrix or the covariance. matrix for the MUSIC or ESPRIT algorithm to estimate AOA and suppress noise. Simulation results show better performance for the new method.

A direction-of-arrival estimation for source signals exploiting 1st-order cyclostationarity property

An array signal model exploiting first-order cyclostationarity of source signals is presented, and an efficient approach to estimate the DOA utilizing the least square (LS) method is developed in this paper. For the cases of single and multiple objects, simulations are made and the results indicate the efficiency of the given method.

Efficient radar target classification using modular neural networks

A radar target classifier based on modular neural networks is presented and its performance compared with that of a classifier based on non-modular neural networks. In this classifier, the response from an unknown target is sent to several waveform predictors that are BP neural networks trained by responses from known targets. The predictor errors are then sent to a classifier using the rule of maximum a posteriori or the rule of modified minimum squared errors. The simulation shows that the new classifier has a good performance on radar target recognition. The method also has other advantages such as easy realization, clear structure and easy expansion.