What impact can shadowing by parts of the aircraft have on GPS signal reception?

Shadowing by parts of the aircraft can significantly impact GPS signal reception by blocking or degrading the signals transmitted from GPS satellites. When a part of the aircraft, such as a wing or fuselage, obstructs the line of sight between the GPS receiver and the satellites, it can lead to either a complete loss of signal or a severe reduction in the signal strength. This phenomenon is particularly critical because GPS relies on signals from multiple satellites to accurately determine position, velocity, and time.

In scenarios of shadowing, the GPS receiver may not be able to receive enough satellite signals to perform a reliable triangulation of its position. This is why the first option is the most accurate — the aircraft’s structure can indeed prevent effective reception of GPS signals, impacting the overall navigation capability of the system.