fig1_23.m
上传用户:szahd2008
上传日期:2020-09-25
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文件大小:2k
- % Use this program to reproduce Fig. 1.23 of text.
- close all
- clear all
- tsc = 2.5; % Scan time i s2.5 seconds
- sigma = 0.1; % radar cross section in m sqaured
- te = 900.0; % effective noise temperature in Kelvins
- snr = 15; % desired SNR in dB
- nf = 6.0; %noise figure in dB
- loss = 7.0; % radar losses in dB
- az_angle = 2; % search volume azimuth extent in degrees
- el_angle = 2; %serach volume elevation extent in degrees
- range = linspace(20e3,250e3,1000); % range to target from 20 Km 250 Km, 1000 points
- pap1 = power_aperture(snr,tsc,sigma/10,range,nf,loss,az_angle,el_angle);
- pap2 = power_aperture(snr,tsc,sigma,range,nf,loss,az_angle,el_angle);
- pap3 = power_aperture(snr,tsc,sigma*10,range,nf,loss,az_angle,el_angle);
- % plot power aperture prodcut versus range
- % figure 1.23a
- figure(1)
- rangekm = range ./ 1000;
- plot(rangekm,pap1,'k',rangekm,pap2,'k -.',rangekm,pap3,'k:','linewidth',1.5)
- grid
- legend('sigma = -20 dBsm','sigma = -10dBsm','sigma = 0 dBsm')
- xlabel ('Detection range in Km');
- ylabel ('Power aperture product in dB');
- % generate Figure 1.23b
- lambda = 0.03; % wavelength in meters
- G = 45; % antenna gain in dB
- ae = linspace(1,25,1000);% aperture size 1 to 25 meter squared, 1000 points
- Ae = 10*log10(ae);
- range = 250e3; % rnage of interset is 250 Km
- pap1 = power_aperture(snr,tsc,sigma/10,range,nf,loss,az_angle,el_angle);
- pap2 = power_aperture(snr,tsc,sigma,range,nf,loss,az_angle,el_angle);
- pap3 = power_aperture(snr,tsc,sigma*10,range,nf,loss,az_angle,el_angle);
- Pav1 = pap1 - Ae;
- Pav2 = pap2 - Ae;
- Pav3 = pap3 - Ae;
- figure(2)
- plot(ae,Pav1,'k',ae,Pav2,'k -.',ae,Pav3,'k:','linewidth',1.5)
- grid
- xlabel('Aperture size in square meters')
- ylabel('Pav in dB')
- legend('sigma = -20 dBsm','sigma = -10dBsm','sigma = 0 dBsm')