radio horizon

She couldn't find out what had happened to the huge tanks until her ship swung back over their radio horizon.

The farthest possible point of propagation is referred to as the "radio horizon".

If the Earth were a perfect sphere and there were no atmosphere, the radio horizon would be a circle.

The nominal range of the system is 450 km, and it is generally limited by the radio horizon.

The radio horizon of the transmitting and receiving antennas can be added together to increase the effective communication range.

Easy approximations for calculating the path loss over distances significantly shorter than the distance to the radio horizon:

The radio horizon is the locus of points at which direct rays from an antenna are tangential to the surface of the Earth.

Using high gain antennas and amplifiers, reliable long-distance wireless links over many miles are possible and only limited by the radio horizon.

Vostok 1 is nearing the VHF radio horizon for Khabarovsk and they respond, "Repeat.

There was a pause as his question was relayed back to the CBG, which by now was below Tombstone's radio horizon.

This system simply turns on the audio of every muted receiver within the radio horizon of the transmitter (i.e. any receiver within the transmitter's "footprint").

Many repeaters are located on hilltops or on tall buildings as the higher location increases their coverage area, sometimes referred to as the radio horizon, or "footprint".

The inversion is capable of allowing very high frequency (VHF) and UHF signal propagation well beyond the normal radio horizon distance.

As for other UHF radio services, reliable range is considered to be line-of-sight and the distance to the radio horizon can be estimated based on antenna height.

The distance to the radio horizon is slightly extended over the geometric line of sight to the horizon, as radio waves are weakly bent back toward the Earth by the atmosphere.

Unlike high frequencies (HF), the ionosphere does not usually reflect VHF waves (called skywave propagation) so transmissions are restricted to the local radio horizon less than 100 miles.

While technically the term includes propagation with larger losses than in standard atmosphere, in practical applications it is most often meant to refer to cases when signal propagates beyond normal radio horizon.

The perigee point of ISO's orbit was below the radio horizon of the mission control centers at both VILSPA and Goldstone, thus forcing the science instruments to be switched off at perigee.

Where terrain allows, mountaintop sites are very attractive for non-AM broadcast stations and others, because it increases the stations' height above average terrain, allowing them to reach further by avoiding obstructions on the ground, and by increasing the radio horizon.

The usual effect of the declining pressure of the atmosphere with height is to bend radio waves down toward the surface of the Earth, effectively increasing the Earth's radius, and the distance to the radio horizon, by a factor around 4/3.