What can interfere with VOR signals at high altitudes?

Interference with VOR (VHF Omnidirectional Range) signals at high altitudes can occur due to other VOR stations. This phenomenon happens because VOR signals are transmitted on specific frequencies and can create overlapping signal areas, especially as altitude increases. At higher altitudes, a pilot may receive signals from multiple VOR stations simultaneously, leading to confusion and potentially incorrect navigation if the wrong station is interpreted.

This interference is particularly critical for pilots flying in areas with closely spaced VOR stations. Since VOR operates in the VHF band, the signals can also be affected by the curvature of the earth, which adds to the potential for signal overlap at altitude.

While commercial radio stations and satellite signals may operate in or near the VHF band, they typically do not interfere with VOR signals in the same manner as other VOR stations do, largely because their signal strength and operating frequencies differ from those of VOR stations. Additionally, the concept of an attractive nuisance does not apply in this context, as it relates more to liability and safety in the physical realm, rather than radio signal interference.