建模雷达信号的传播

c = physconst (“光速”);R0 = [100 1 e3 10 e3];频率= (1:1000)。”* 1 e9;apathloss = fspl (R0, c /频率);重对数(频率/ 1 e9 apathloss);网格在;ylim(200年[90]);传奇(的范围:100,的范围:1公里,范围:10公里的,“位置”,“西北”);包含(“频率(GHz)”);ylabel (路径损耗(dB)”);标题(自由空间路径损耗的);

R0 = 5 e3;% 5公里范围内rainrate = (1 4 20);%雨率毫米/小时el = 0;% 0度的仰角τ= 0;%水平极化为m = 1:元素个数(rainrate) rainloss_itu(:,米)= rainpl (R0、频率、rainrate (m), el,τ)';rainloss_crane (:, m) = cranerainpl (R0、频率、rainrate (m), el,τ)';结束重对数(频率/ 1 e9 rainloss_itu);持有在;集(gca),“ColorOrderIndex”1);%重置颜色指数更好的比较重对数(频率/ 1 e9 rainloss_crane,“——”);持有从;网格在;传奇(“小雨(ITU)”,“中雨(ITU)”,“大雨(ITU)”,…“小雨(起重机)”,“中雨(起重机)”,“大雨(起重机)”,…“位置”,“东南”);包含(“频率(GHz)”);ylabel (“衰减在5公里(dB)”)标题(“雨衰减为水平极化的);

频率= (1:20)* 1 e9;R0 = 1 e3;% 1公里范围内snowrate = (0.1 - 1.5 4);%等效水含量在毫米/小时为m = 1:元素个数(snowrate)积雪损失(:,米)= snowpl (R0、频率、snowrate (m));结束重对数(频率/ 1 e9,积雪损失);网格在;传奇(“小雪”,“温和的雪”,“大雪”,…“位置”,“东南”);包含(“频率(GHz)”);ylabel (在1公里的衰减(dB)”)标题(“雪衰减”);

频率= (10:1000)* 1 e9;T = 15;% 15摄氏度waterdensity = (0.01 0.05 0.5);% g / m ^ 3中液态水的密度为m = 1:元素个数(waterdensity) fogloss(:,米)= fogpl (R0,频率,T, waterdensity (m)) ';结束重对数(频率/ 1 e9 fogloss);网格在;传奇(“轻雾”,“中等雾”,“大雾”,“位置”,“东南”);包含(“频率(GHz)”);ylabel (在1公里的衰减(dB)”)标题(“雾衰减”);

身高= 2 e3;el = 5;%仰角atmloss_low = tropopl (R0、频率、身高、el、“LatitudeModel”,“低”);atmloss_mid = tropopl (R0、频率、身高、el、“LatitudeModel”,“中期”);atmloss_high = tropopl (R0、频率、身高、el、“LatitudeModel”,“高”);重对数(频率/ 1 e9 atmloss_low);持有在;重对数(频率/ 1 e9 atmloss_mid);重对数(频率/ 1 e9 atmloss_high);持有从;网格在;传奇(低纬度地区的,中纬度的,高纬度地区的,“位置”,“西北”);包含(“频率(GHz)”);ylabel (在1公里的衰减(dB)”)标题(“大气气体衰减”);

R = 1 e3:1e3:100e3;%的传播范围el = 0.05;%仰角身高= (10 100 200);%雷达平台的高度为m = 1:元素个数(高度)lenloss(:,米)= lenspl (R,高度(m), el);结束semilogy (R / 1 e3, lenloss);网格在;传奇(身高:10米的,的高度:100米,的高度:200米,“位置”,…“东南”);包含(的传播距离(公里));ylabel (“衰减(dB)”)标题(“大气透镜衰减”);

poltx = [0, 1];% (H、V)极化polrx = [0, 1];postx = (0, 0, 0);posrx = (100, 0, 0);frmtx =眼(3);%传输帧与惯性卷= 0:180;为m = 1:元素个数(卷)frm_r = rotx(卷(m));ρ(m) = polloss (poltx、polrx posrx, frm_r, postx, frmtx);结束semilogy(卷,ρ);网格在;包含(横摇角(度));ylabel (“衰减(dB)”);标题(衰减由于极化失配的);

频率= (1.06 - 5.7)* 1 e9;% l波段和c波段传输频率(赫兹)antht = 12;%天线的高度(米)rngfs = 100;%空间探测距离(公里)为m = 1:元素个数(频率)[vcp {m}, vcpang {m}] = radarvcd(频率(m), rngfs, antht);结束

[~ N] = refractiveidx (0);%大气折射率的表面helperPlotBlakeChart (vcp vcpang N)

tgtht = 1 e3;%的目标高度(米)R = (50:200) * 1 e3;%传播范围(米)Re = effearthradius;%有效地球半径(米)Rd =√2 * Re) * sqrt (antht) +√(tgtht));%衍射范围F = 0(元素个数(频率),元素个数(R));为m = 1:元素个数(频率)F (m,:) = radarpropfactor (R,频率(m), antht, tgtht,“SurfaceHeightStandardDeviation”0,“SurfaceSlope”,0);结束helperPlotPropagationFactor (R, F, Rd)

频率= 3.3 e9;%频率(赫兹)elbw = 30;%海拔波束宽度(度)Rkm = 1:0.1:120;%范围(公里)R = Rkm。* 1 e3;%范围(米)[htsd, beta0] = searoughness (1);%海面anht = 20 + 2 * htsd;%雷达高度(米)tgtht = (anht + 1):施用;%的目标高度(米)%计算结合环境损失不同高度和范围[PLdB, PLdBNorm] = helperCombineEnvLosses (R,频率,anht、tgtht htsd, beta0, elbw);%的情节结合损失对不同高度和范围helperPlotCombinedEnvLosses (Rkm频率、anht tgtht, PLdBNorm)

波形= phased.RectangularWaveform (脉冲重复频率的,250);wav =波形();

fc = 1.9 e9;频道= twoRayChannel (“PropagationSpeed”c“OperatingFrequency”、fc);

pos_radar = (0, 0, 12);pos_target = (50 e3; 0; 1.65 e3);vel_radar = (0, 0, 0);vel_target = (-200, 0, 0);y2ray =通道(vel_radar, wav, pos_radar, pos_target vel_target);

(延迟,夹住)= helperPlotDelayAndDopplerShift (wav, y2ray, waveform.SampleRate);

离间=延迟* c * 1 e - 3%公里

estRangeRate = -dop2speed(夹住,freq2wavelen (fc))% m / s

L_2ray = pow2db (bandpower (wav)) -pow2db (bandpower (y2ray))

L_ref = fspl(规范(pos_target-pos_radar), c / fc)

pos_target = (50 e3; 0; 1.8 e3);y2ray =通道(vel_radar, wav, pos_radar, pos_target vel_target);L_2ray = pow2db (bandpower (wav)) -pow2db (bandpower (y2ray)) L_ref = fspl(规范(pos_target-pos_radar), c / fc)

%模拟信号衰落在目标高度从1公里到3公里hTarget = linspace (1 e3、3 e3);pos_target = repmat ([50 e3; 0; 1.6 e3],[1元素个数(hTarget)]);:pos_target (3) = hTarget;vel_target = repmat (vel_target[1元素个数(hTarget)]);释放(渠道);y2ray =通道(repmat (wav,[1元素个数(hTarget)]), pos_radar, pos_target, vel_radar, vel_target);

L2ray = pow2db (bandpower (wav)) -pow2db (bandpower (y2ray));clf;情节(hTarget L2ray);包含(的目标高度(米));ylabel (“单向传播损失(dB)”);标题(“多路径衰落观察到目标”);网格在;

bw = 0.08 *俱乐部;pulse_width = 1 / bw;fs = 2 * bw;波形= phased.RectangularWaveform (“SampleRate”fs,脉冲重复频率的,2000,“脉冲宽度”,pulse_width);wav =波形();

频道= widebandTwoRayChannel (“PropagationSpeed”c“OperatingFrequency”足球俱乐部,“SampleRate”fs);

y2ray_wb =通道(repmat (wav,[1元素个数(hTarget)]), pos_radar, pos_target, vel_radar, vel_target);L2ray_wb = pow2db (bandpower (wav)) -pow2db (bandpower (y2ray_wb));持有在;情节(hTarget L2ray_wb);持有从;传奇(“窄带”,“宽带”);

函数helperPlotPropagationFactor (R, F, Rd)%的阴谋干涉和衍射区域补丁[minF, maxF] =边界(F (:));maxF =装天花板((maxF + 10) / 10) * 10;minF =地板((minF-10) / 10) * 10;yPatch = [minF minF maxF maxF];c1 = (0.3010 0.7450 0.9330);c2 = 0.4470 - 0.7410 [0];clf%明确当前图填充([(1)Rd Rd R (1)] / 1 e3, yPatch, c1,“EdgeColor”,“没有”,“FaceAlpha”,0.25)在填充([Rd(结束)R(结束)Rd) / 1 e3, yPatch, c2,“EdgeColor”,“没有”,“FaceAlpha”,0.25)%的阴谋单向传播的因素集(gca),“ColorOrderIndex”1);%重置颜色指数情节(R / 1 e3, F);ylim ([minF maxF])网格在;包含(的距离(公里));ylabel (“传播因素(dB)”);标题(“单向传播因素在1公里以上表面”);传奇(“干扰区域”,“衍射区域”,…的l波段(1.06 GHz) ',“c波段(5.7 GHZ)”,…“位置”,“西南”)举行从结束

函数helperPlotBlakeChart (vcp vcpang N)%计算折射指数DelN = -7.32 * exp (0.005577 * N);rexp日志(N =。/ (N + DelN));次要情节(211)blakechart (vcp {1}, vcpang {1},“SurfaceRefractivity”N“RefractionExponent”,rexp);传奇(的l波段(1.06 GHz) ')包含(”)标题(“布雷克图——天线高度:12米(vcp)次要情节(212)blakechart {2}, vcpang {2},“SurfaceRefractivity”N“RefractionExponent”,rexp);allc =得到(gca,“孩子”);集(allc (11),“颜色”(0.8500 0.3250 0.0980))%改变线的颜色标题(”)传说(“c波段(5.7 GHz)”)结束

函数(延迟,夹住)= helperPlotDelayAndDopplerShift (wav, y2ray, Fs)%的阴谋脉冲传播和传播t = 1 e6 *(0:元素个数(wav) 1)”/ Fs;次要情节(211)yyaxis左情节(t, abs (wav)) ylabel (“级”)yyaxis正确的情节(t、abs (y2ray))网格在轴垫xlim(300[0])包含([“时间”char (0 x00b5)' s) '])ylabel (“级”)标题(“传播和脉冲传播”)%注释延迟= midcross (abs (y2ray), t / 1 e6,“MidPercentReferenceLevel”,80);%秒延迟=延迟(1);xl =参照线(1 e6 *延迟,“-”。,…%注释{[num2str(轮(1)e6 *延迟)),' 'char (0 x00b5)年代的延迟)},“颜色”[0.8500 0.3250 0.0980]);xl。LabelVerticalAlignment =“中间”;xl。LabelHorizontalAlignment =“左”;xl。线宽= 2;%绘制功率谱次要情节(212)[p f] = pspectrum (Fs (wav y2ray),“FrequencyLimits”,-20年e3 20 e3);p = abs (p);阴谋(1 e - 3 * f,重新调节(p,“InputMin”最小(p),“InputMax”马克斯(p)));轴垫网格在[~,idx] = max (p);夹住= f (idx (2)) - f (idx (1));%赫兹包含(的频率(赫兹))ylabel (“级”)标题(“归一化光谱”1)xl =参照线(e - 3 *夹住,“-”。,…%注释{多普勒频移的,(num2str (e - 3轮(计划)* 1)“赫兹”)},“颜色”[0.8500 0.3250 0.0980]);xl。LabelVerticalAlignment =“底”;xl。线宽= 2;传奇(“传播”,“传播”)结束

函数[PLdB, PLdBNorm] = helperCombineEnvLosses (R,频率,anht、tgtht htsd, beta0, elbw)%计算结合环境损失numHt =元素个数(tgtht);numR =元素个数(R);F = 0 (numHt numR);为ih = 1: numHt F (ih:) = radarpropfactor (R,频率、anht tgtht (ih),…“SurfaceHeightStandardDeviation”htsd,“SurfaceSlope”beta0,…“ElevationBeamwidth”,elbw);结束%自由空间传播损耗Lspl_dB = 2 * fspl (R, freq2wavelen(频率));为双向% 2%执行对流层损失计算高度角的一个子集,%因为光线折射可以花很长时间。元素个数= 10;minEl = height2el (tgtht (1) anht, R(结束));%分钟仰角(度)maxEl = height2el (tgtht(结束),anht, R (1));%最大仰角(度)elSubset = linspace (minEl maxEl元素个数);LtropoSubset = 0(元素个数,numR);为ie = 1:元素个数LtropoSubset(即:)= tropopl (R,频率、anht elSubset (ie));结束%插入对流层损失感兴趣的所有高度角Ltropo = 0 (numHt numR);为ir = 1: numR el = height2el (tgtht anht, R (ir));Ltropo (:, ir) = interp1 (elSubset, LtropoSubset (:, ir), el);结束PLdB = 2 * F - Lspl_dB Ltropo;为双向% 2PLdBNorm = PLdB - max (PLdB (:));结束

函数helperPlotCombinedEnvLosses (Rkm频率、anht tgtht, PLdBNorm)%的情节结合损失对不同高度和范围惠普= pcolor (Rkm tgtht PLdBNorm);集(惠普、“EdgeColor”,“没有”);标题([num2str(频率/ 1 e9)“GHz s波段雷达”])副标题([num2str(圆(anht))“米水”])包含(的距离(公里))ylabel (身高(米)的)colormap (“喷气机”);-150 caxis ([0]) hC = colorbar;hC.Label。字符串=“归一化双向传播损失(dB)”;结束