Question

Consider an X-band (10 GHz) radar on an aircraft traveling at 100 m/s. Assume the 3-dB azimuth beamwidth of the antenna is 3º. Compute the Doppler shift Fo of a scatterer on the antenna boresight and the Doppler bandwidth (30 across the beam for squint angles of 0°, 30°, 60°, and 90°.

Answer 1

The Doppler shift and Doppler bandwidth of a scatterer on the antenna boresight can be calculated using the formulas Fo = Fo + (v/c) * Fo and Bd = 2 * Fo * (v/c) * cot(theta) respectively.

Step-by-step explanation:

The Doppler shift of a scatterer on the antenna boresight can be calculated using the formula:

Fo = Fo + (v/c) * Fo

where Fo is the original frequency, v is the velocity of the scatterer, and c is the speed of light. In this case, since the scatterer is on the antenna boresight, the velocity is equal to the velocity of the aircraft, which is 100 m/s.

The Doppler bandwidth can be calculated using the formula:

Bd = 2 * Fo * (v/c) * cot(theta)

where Bd is the Doppler bandwidth, Fo is the original frequency, v is the velocity of the scatterer, c is the speed of light, and theta is the azimuth beamwidth.

Plugging in the given values: Fo = 10 GHz, v = 100 m/s, c = 3 x 10^8 m/s, theta = 3 degrees

We can calculate the Doppler shift Fo and the Doppler bandwidth for the given squint angles of 0°, 30°, 60°, and 90° using the above formulas.