Whilst the learning objectives do not specify the frequency band of airborne weather radars, it is a very common question, and the answer is that AWRs operate in the SHF band (Super High Frequency). This can also be calculated using the formula;

speed of light = frequency x wavelength

rearranged is;

frequency = speed of light / wavelength
frequency = 3x10⁸ (m/s) / 0.03 (m) = 1x10¹⁰ (Hz)

The frequency is therefore around 10 GHz, which is between 3 and 30 GHz, and is therefore in the SHF band, as shown in the annex above.

As it turns out, the exact wavelength used is 3.2 cm and therefore the selected frequency for AWR is 9.375 GHz (9375 MHz). AWR must be optimised not to detect very small particles such as thin fog but to accurately identify rain and hail particles within storms.

• Too small wavelengths will result in reflection from very small particles. Larger wavelengths result in the waves bending around particles of interest.