Then, by extrapolating current range and altitude difference to anticipated future values, it determines if a potential collision threat exists.

This uses the same sensors, but a super-smart algorithm also detects where each surrounding car is, draws a vector polygon around it to calculate speed and course, and figures out whether it represents a collision threat.

Peterson recovered, but then observed a rescue helicopter that seemed to pose a collision threat.

In that time, he said, pilots had been cautioned about a possible collision threat 301 times and had received the more urgent escape advisories 34 times.

A8 Two jet airliners missed colliding over North Carolina on Sunday by less than a mile and a half, and a emergency device in one of the planes, designed to warn of collision threats, didn't work.

All that space junk poses a collision threat to current and future space missions, manned or robotic, government or commercial.

Commuter airliners carrying less than 20 passengers would be required only to carry much cheaper, simpler devices that would alert the crew to collision threat but would not be able to calculate recommended evasive maneuvers.

Serious interest in the collision threat first arose in the 1970's as astronomers scanned the skies and geologists studied giant impact craters.

This equipment, like the devices on larger airliners, would alert pilots to a collision threat but would not advise pilots of what evasive maneuvers to take.

In the meantime, efforts have focused on the airport grounds, with booming propane cannons, gull-shooting teams of marksmen, recorded gull distress calls - and now falcons - used to cut the collision threat.