CMRT Signal Processing & Antenna Theory 2

Question 1

What is the purpose of a matched filter in radar signal processing?

Accepted Answer

To maximize the signal-to-noise ratio at the output

Answer

A matched filter maximizes SNR by correlating the received signal with a replica of the transmitted signal.

Question 2

Which antenna parameter describes how efficiently an antenna converts input power into radiated electromagnetic waves?

Accepted Answer

Radiation efficiency

Answer

Radiation efficiency is the ratio of radiated power to input power, accounting for ohmic losses in the antenna.

Question 3

In marine radar, what does STC (Sensitivity Time Control) primarily compensate for?

Accepted Answer

Strong returns from nearby sea clutter

Answer

STC reduces receiver gain for returns arriving shortly after transmission to suppress strong sea clutter from nearby waves.

Question 4

What phenomenon causes the radar horizon to extend slightly beyond the geometric horizon?

Accepted Answer

Tropospheric refraction bending the radar beam downward

Answer

Tropospheric refraction causes radar waves to bend slightly downward, extending the radar horizon beyond the geometric horizon.

Question 5

A slotted waveguide antenna for marine radar primarily radiates energy through:

Accepted Answer

Slots cut into the waveguide walls that act as individual radiators

Answer

Slots cut into the broad wall of the waveguide interrupt surface currents, causing each slot to radiate as a small dipole.

(CMRT) Certified Marine Radar Technician Practice Test