雷达方程

或

Pt为发射峰值功率，G为天线增益，lamda为载波波长，sigma为目标RCS,K为玻尔兹曼常数，Ts为以热力学温度为单位的有效噪声温度，B为带宽，L 为雷达损耗，F为噪声系数，R为雷达与目标间距离。

   1:  function [snr] = radar_eq(pt, freq, g, sigma, b, nf, loss, range)

   2:  % This program implements Eq. (1.63)

   3:  c = 3.0e+8; % speed of light

   4:  lambda = c / freq; % wavelength

   5:  p_peak = 10*log10(pt); % convert peak power to dB

   6:  lambda_sqdb = 10*log10(lambda^2); % compute wavelength square in dB

   7:  sigmadb = 10*log10(sigma); % convert sigma to dB

   8:  four_pi_cub = 10*log10((4.0 * pi)^3); % (4pi)^3 in dB

   9:  k_db = 10*log10(1.38e-23); % Boltzman's constant in dB

  10:  to_db = 10*log10(290); % noise temp. in dB

  11:  b_db = 10*log10(b); % bandwidth in dB

  12:  range_pwr4_db = 10*log10(range.^4); % vector of target range^4 in dB

  13:  % Implement Equation (1.63)

  14:  num = p_peak + g + g + lambda_sqdb + sigmadb;

  15:  den = four_pi_cub + k_db + to_db + b_db + nf + loss + range_pwr4_db;

  16:  snr = num - den;

  17:  return

 
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