How the use of sky waves affects the measured time difference in Loran C?

The use of sky waves in Loran C can introduce errors in the measured time difference due to signal distortion, multipath interference, and signal attenuation. These factors can cause the signal to arrive at the receiver with a delay or in an altered state, leading to inaccuracies in determining the time difference between the signals from different transmitters. These errors can be minimized through signal processing techniques and calibration procedures.