Microwave remote sensing of the ocean

   1 def eps_water_func(T,S,f):
   2 
   3     """Complex dielectric constant of seawater by Klein and Swift (1977)"""
   4     T=T-273.15
   5     omega=2*pi*f
   6     eps_0=8.854*10**(-12)
   7     eps_inf=4.9
   8 
   9     eps_s_T=87.134-1.949*10**(-1)*T-1.276*10**(-2)*T**2+2.491*10**(-4)*T**3
  10     a_ST=1.+1.613*10**(-5)*S*T-3.656*10**(-3)*S+3.210*10**(-5)*S**2-4.232*10**(-7)*S**3
  11     eps_s=eps_s_T*a_ST
  12 
  13     tau_T0=1.768*10**(-11)-6.086*10**(-13)*T+1.104*10**(-14)*T**2-8.111*10**(-17)*T**3
  14     b_ST=1.+2.282*10**(-5)*S*T-7.638*10**(-4)*S-7.760*10**(-6)*S**2+1.105*10**(-8)*S**3
  15     tau=tau_T0*b_ST
  16 
  17     delta=25-T
  18     beta=2.0333*10**(-2)+1.266*10**(-4)*delta+2.464*10**(-6)*delta**2-S*(1.849*10**(-5)-2.551*10**(-7)*delta+2.551*10**(-8)*delta**2)
  19     sigma_25S=S*(0.182521-1.46192*10**(-3)*S+2.09324*10**(-5)*S**2-1.28205*10**(-7)*S**3)
  20     sigma=sigma_25S*exp(-delta*beta)
  21 
  22     eps_water=eps_inf+(eps_s-eps_inf)/(1+1j*omega*tau)-1j*sigma/(omega*eps_0)
  23     return eps_water