Signal-to-Noise (SNR) for SAR (1)

$SNR_"image" = ( P_t * G_A * A_e * sigma * G_r * G_a )/( (4 pi)^2 * R ^4 * L_(radar) * L_(atmos) * (k * T * F_N ) * B_N )$

$(P_t)"Transmitter signal power"$

$(G_A)"Transmitter antenna gain factor"$

$(A_e)"Receiver antenna effective area"$

$(R)"Magnitude of the range vector from target to antenna"$

$(sigma)"Target Radar Cross Section"$

$(L_(radar))"Microwave transmission loss factor due to miscellaneous sources"$

$(L_(atmos))"Atmospheric loss factor due to the propagating wave"$

$(T)"Nominal scene noise temperature"$

$(F_N)"System noise factor for the receiver"$

$(B_N)"Noise bandwidth at the antenna port"$

$(G_r)"SNR gain due to range processing (pulse compression)"$

$(G_a)"SNR gain due to azimuth processing (coherent pulse integration)"$