Space wave propagation involves radio waves that travel directly or after reflecting off the Earth's surface within the lower 20 km of the atmosphere. These waves can propagate line-of-sight between transmitter and receiver antennas in the VHF and UHF bands. Space waves follow two paths - direct or ground reflected - and may arrive in or out of phase, causing signal fluctuations. The maximum transmission distance is limited by the Earth's curvature and obstructions that can cause shadowing effects. Refractive phenomena like super-refraction can sometimes extend the radio horizon.
Space wave propagation involves radio waves that travel directly or after reflecting off the Earth's surface within the lower 20 km of the atmosphere. These waves can propagate line-of-sight between transmitter and receiver antennas in the VHF and UHF bands. Space waves follow two paths - direct or ground reflected - and may arrive in or out of phase, causing signal fluctuations. The maximum transmission distance is limited by the Earth's curvature and obstructions that can cause shadowing effects. Refractive phenomena like super-refraction can sometimes extend the radio horizon.
Meelis Tammre and Anna Zilderberg from Estonia won a couples carrying race in Finland with a time of one minute four seconds. The race involved a man carrying his partner over 254 meters that included hurdles and a chest-high water pool. Thirty-six couples from eight countries participated in the event, which was watched by up to 6,000 people in a forest clearing near the Arctic Circle. Tammre said he was exhausted but happy to finally win first place after coming in second three times previously.
Meelis Tammre and Anna Zilderberg from Estonia won a couples carrying race in Finland with a time of one minute four seconds. The race involved a man carrying his partner over 254 meters that included hurdles and a chest-high water pool. Thirty-six couples from eight countries participated in the event, which was watched by up to 6,000 people in a forest clearing near the Arctic Circle. Tammre said he was exhausted but happy to finally win first place after coming in second three times previously.