| || Measuring Errors’ Spectrum of the Artillery Radar Stations
Author : Madej, Wieslaw
Source : Defence Science Journal ; Vol:59(2) ; 2009 ; pp 162-165
Subject : 621.396.9 Radars;623.4 Armaments and Ballistics
Keywords : Autocorrelation;Variance;Spectral density of power;Measurement;Artillery radar station;Ballistic computations;Simulation analysis;Digital prediction system;Algorithm;Error spectrum
Abstract : The simulation analysis of the measuring errors of the artillery radar stations is presented in this paper. This analysis enables the proper designing of the smoothing filters of the data for the ballistic module and determination of the components of the velocity of the target. They are derivatives of the signals representing coordinates of the target, and as such, can introduce huge errors during computations of derivatives.
| || Software-based Solution for Analysis and Decoding of FSK-2 Modulated, Baudot-coded Signals
Author : Malhotra, Mukesh;Gupta, Neena;Prasad, R.S.
Source : Defence Science Journal ; Vol:56(2) ; 2006 ; pp 259-268
Subject : 681.3:355 Computer Applications in Defence;681.3 Computer Science
Keywords : Frequency shift keying;Fast Fourier transform;Autocorrelation;Sliding window;Hopping window;FSK;FFT
Abstract : In the present-day scenario, digital communication has become predominant choice over analog communication worldwide. Digital modulation schemes form the main block of the digital communication. Among these, frequency shift keying (FSK-2) is a widely used technique employed for Baudot-coded english text transmission. A Baudot-coded-FSK-2 modulated signal was simulated corresponding to an english text file. A technique has been developed for its analysis and decoding in the MATLAB environment. This technique does the signal analysis, its parameter extraction, and then digital demodulation, to retrieve its corresponding composite bit-stream. An efficient method for edge detection using the number of zero-crossings has been devised and implemented successfully. From the composite bit-stream, overhead bits were removed and decoding was performed to get back the text output.