What characteristic defines a TACAN antenna's electrical length?

The characteristic that defines a TACAN antenna's electrical length as one-half wavelength is significant because this length is optimal for efficient transmission and reception of radio waves. The half-wavelength design allows the antenna to resonate at the frequency it is designed for, enhancing its performance in both transmitting signals and receiving echoes from aircraft.

In this configuration, the antenna's dimensions are matched to the wavelength of the radio signals it operates with, which leads to improved impedance matching and minimizes signal loss. This result is crucial in navigation systems like TACAN, where precise location data is required. Utilizing a half-wavelength antenna helps ensure that the signal is strong and coherent, key attributes for effective functioning in air navigation applications.

Additionally, a TACAN system's operational efficiency relies on this design to achieve the desired angular resolution and accuracy, essential for guiding aircraft in various operational environments. This is why the choice of a half-wavelength dimension aligns with the technical requirements of TACAN antennas.