Optimal frequency selection of multi-channel O2-band different absorption barometric radar for air pressure measurements

•Differential absorption barometric radar globally measures surface air pressure.•The optimal selection of frequencies for O2 differential absorption is achieved.•The required differential absorption depth between a radar frequency pair is 0.5.•Listed frequencies would not significantly contaminate passive microwave retrieval.

Through theoretical analysis, optimal selection of frequencies for O2 differential absorption radar systems on air pressure field measurements is achieved. The required differential absorption optical depth between a radar frequency pair is 0.5. With this required value and other considerations on water vapor absorption and the contamination of radio wave transmission, frequency pairs of present considered radar system are obtained. Significant impacts on general design of differential absorption remote sensing systems are expected from current results.