Received this edited post (reportedly from Electronic Media, March 5. p14) from an AVS contributor who wishes to remain anonymous. I can't verify its accuracy but thought it of interest to HDTV fans.
WPIX-TV is based in the Daily News building at 42nd Street and Second Avenue in Manhattan. But the Tribune Co.-owned WB station can clearly cover news live from as far away as the tip of Long Island,
Poughkeepsie, N.Y., Atlantic City, N.J., and out west to the Poconos in Pennsylvania, thanks to its new all-digital news helicopter. It was the sweet culmination of a two-year project to get multipath-free reception with perfectly clear video and audio. .....
"There was a crystal-clear picture to viewers at home the first day out, so we tried some distance shots," recalled WPIX Engineering Manager Ralph Augenfeld. "We went up the Hudson River almost 50 miles without breakup, refueled and went west to the Delaware Water Gap (Pennsylvania border) and over a mountain range to a Pocono ski resort (about 80 miles west of the receiver site). And that's air miles - which doubled to tripled our traditional distance."
The next day was even better. Air 11 headed east to the tip of Long Island, about 110 miles (98 air miles away) to the Montauk Point lighthouse, catching sight of Connecticut across the Long Island Sound. According to Mr Gano, "We ran out of Long Island before we ran out of signal."
Both Mr Gano and Mr Augenfeld attribute much of their success to COFDM, a transmission technique that splits bandwidth into many narrow sub-band channels, which are then modulated by a low-rate data stream.
"One of the main advantages of COFDM vs. analog FM is that all the ghosts are eaten up like Pac-Man," Mr Augenfeld said. "What normally added noise to the picture - signals arriving late to the receiver due to bounces off the millions of obstructions from the Manhattan skyline - are now all added together to improve the picture. Each bounce actually gives you more signal energy."
In addition to improving the picture, COFDM also calmed the fear or running out of microwave bandwidth, which has nagged broadcasters for the past couple of years.
WPIX-TV is based in the Daily News building at 42nd Street and Second Avenue in Manhattan. But the Tribune Co.-owned WB station can clearly cover news live from as far away as the tip of Long Island,
Poughkeepsie, N.Y., Atlantic City, N.J., and out west to the Poconos in Pennsylvania, thanks to its new all-digital news helicopter. It was the sweet culmination of a two-year project to get multipath-free reception with perfectly clear video and audio. .....
"There was a crystal-clear picture to viewers at home the first day out, so we tried some distance shots," recalled WPIX Engineering Manager Ralph Augenfeld. "We went up the Hudson River almost 50 miles without breakup, refueled and went west to the Delaware Water Gap (Pennsylvania border) and over a mountain range to a Pocono ski resort (about 80 miles west of the receiver site). And that's air miles - which doubled to tripled our traditional distance."
The next day was even better. Air 11 headed east to the tip of Long Island, about 110 miles (98 air miles away) to the Montauk Point lighthouse, catching sight of Connecticut across the Long Island Sound. According to Mr Gano, "We ran out of Long Island before we ran out of signal."
Both Mr Gano and Mr Augenfeld attribute much of their success to COFDM, a transmission technique that splits bandwidth into many narrow sub-band channels, which are then modulated by a low-rate data stream.
"One of the main advantages of COFDM vs. analog FM is that all the ghosts are eaten up like Pac-Man," Mr Augenfeld said. "What normally added noise to the picture - signals arriving late to the receiver due to bounces off the millions of obstructions from the Manhattan skyline - are now all added together to improve the picture. Each bounce actually gives you more signal energy."
In addition to improving the picture, COFDM also calmed the fear or running out of microwave bandwidth, which has nagged broadcasters for the past couple of years.
