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How can radar detect meteors that are too faint or occur during daylight?

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Meteor and meteoroid The Cabin Creek meteorite, an iron (nickel-iron alloy) meteorite that was observed to fall in northwestern Arkansas on March 27, 1886. Its characteristic pattern of “thumbprint” dimples, or regmaglypts, is the result of melting and consequent ablation of its surface as it traveled through the atmosphere. The meteorite is likely a fragment of one of the M class asteroids, which show significant nickel-iron in their surface material.

Radar can detect meteors that are too faint for the human eye or occur during daylight because it does not rely on visible light. Instead, radar systems emit short bursts of radio-frequency energy that are reflected by the column of ionized gases—the meteor trail—formed as a meteoric body passes through the upper atmosphere.12

Because these radio waves can detect the ionized trail regardless of ambient light conditions, radar allows for the observation of meteors during the day and the detection of objects that are too faint to be seen visually. By measuring the time lapse between the transmitted and reflected signals, radar can determine the distance to the meteor, while the rate of change in that distance provides the object's velocity in the line of sight.1