In[]:=
Module[{N=5,A,k,omega,theta,phi,t=0},A=RandomVariate[NormalDistribution[1,0.2],N];omega=RandomVariate[NormalDistribution[1,0.2],N];k=RandomReal[{0.5,1.5},N];theta=RandomReal[{0,2Pi},N];phi=RandomReal[{0,2Pi},N];Plot3D[Sum[A[[i]]Sin[k[[i]](xCos[theta[[i]]]+ySin[theta[[i]]])-omega[[i]]t+phi[[i]]],{i,1,N}],{x,-10,10},{y,-10,10},PlotRange{-5,5},ColorFunction"Rainbow",MeshNone,BoxedFalse,AxesFalse]]
Out[]=
