Which radar band is most affected by attenuation due to Oxygen?

The W-band is most affected by attenuation due to oxygen because it operates at higher frequencies, specifically in the range of 75 to 110 GHz. At these higher frequencies, atmospheric gases, particularly oxygen, have significant spectral lines that can absorb and scatter radar signals, leading to increased attenuation. As the frequency of the radar signal increases, the effect of attenuation becomes more pronounced, making W-band systems more susceptible to signal degradation in the presence of moisture and gaseous absorption in the atmosphere.

In contrast, lower frequency bands such as L-band and S-band experience much less attenuation from oxygen. These frequencies do not coincide with the strong absorption lines of oxygen, thus they can propagate through the atmosphere with a relatively lower degree of signal loss. Although K-band also operates at a higher frequency than L-band and S-band, it is still not as severely impacted by oxygen attenuation as W-band frequencies are. Therefore, W-band is the most affected by oxygen absorption due to its higher frequency, aligning it closely with the absorption characteristics of atmospheric gases.