Showing papers by "National University of Defense Technology published in 1991"
TL;DR: In this article, the scattering of low energy electrons from Mg, Zn and Cd atoms is calculated with the Dirac equation while paying attention to the spin polarization enhanced by the low-lying shape resonance states.
6 citations
20 May 1991
TL;DR: The authors present the detailed derivation of the WMEKF (weighted modified extended Kalman filter) algorithm for a bistatic system, in which the passive observer measures the azimuth, elevation, and time difference.
Abstract: The authors present the detailed derivation of the WMEKF (weighted modified extended Kalman filter) algorithm for a bistatic system, in which the passive observer measures the azimuth, elevation, and time difference. A unique multistatic system composed of netted-bistatic systems is proposed. The processed results at each bistatic system are sent over a communication network to a central processor and processed with the WLS (weighted least sequence) algorithm. The tracking performance of the multistatic system is evaluated by means of the Monte Carlo simulation technique. >
4 citations
20 May 1991
TL;DR: In this paper, the Fisher information matrix has a simple form and the Cramer-Rao lower bound is derived for a specific trajectory that is symmetrical about the closest point of approach.
Abstract: A method used for estimation of the position of a moving pulse emitter with constant pulse repeat interval by a single observer is studied. The performance of the estimator depends on the emitter trajectory. A specific trajectory that is symmetrical about the closest point of approach is considered. Under this condition the Fisher information matrix has a simple form. The Cramer-Rao lower bound is then derived. >
2 citations
Journal Article•
TL;DR: In this paper, an iterative approximate 3D line searching algorithm based upon the geometric representation of lines (for non-maneuvering targets in space) in a 3D space is derived.
1 citations
20 May 1991
TL;DR: An attempt is made to develop a high-speed detection scheme for moving and stationary point targets registered in an IR (infrared) image sequence and an iterative approximate 3-D line searching algorithm based upon the geometric representation of lines is derived.
Abstract: An attempt is made to develop a high-speed detection scheme for moving and stationary point targets registered in an IR (infrared) image sequence. An iterative approximate 3-D line searching algorithm (for non-manoeuvering targets in space) based upon the geometric representation of lines is derived. The convergence of the algorithm is proved. An analysis of the algorithm yields the theoretical detection performance. Statistical experiment results show the effectiveness and the computational efficiency of the algorithm in the case of low signal-to-noise ratio. The algorithm may be employed to satisfy the real-time processing requirement of an IR homing. >
1 citations
01 Jan 1991
TL;DR: A method of high-resolution spatial spectrum analysis with applications of neural networks is proposed and a new formula of energy function is proposed to this special problem.
Abstract: A method of high-resolution spatial spectrum analysis with applications of neural networks is proposed. Based on MUSIC algorithm, three kinds of neural networks are introduced into this field. A new formula of energy function is proposed to this special problem.
1 citations
20 May 1991
TL;DR: In this article, an experimental scheme of a small steady-state error tracking system was proposed, and the principle of the tracking system is described, the time-domain and frequency-domain performance was discussed.
Abstract: In a frequency-agile magnetron radar, the cavity frequency tracking system of the tuning magnetron is used to control the transmitted pulse sequences and carry out the auto-track of the local oscillator. An experimental scheme of a small steady-state error tracking system is proposed, and the principle of the tracking system is described. The time-domain and frequency-domain performance of the tracking system is discussed. Experimental results indicate that this system has a high tracking accuracy. >