Which statement best describes a major drawback of primary radar systems?

Which statement best describes a major drawback of primary radar systems?

• A. They provide altitude information but are affected by weather.
• B. They operate without any power source.
• C. They require GPS to function.
• D. They are very susceptible to atmospheric conditions and the size of the target, and do not provide information about altitude.

Answer: (D)

Primary radar systems detect objects by sending out a pulse and listening for the reflection, giving you range and bearing but not direct altitude. The amount of energy reflected back depends on the target’s radar cross-section, so larger or more reflective targets produce stronger returns, while small targets can be hard to detect. Weather and atmospheric conditions—like heavy rain or ducting—also affect the signal, attenuating or distorting returns and making detection less reliable. Taken together, the key drawback is that you can’t directly obtain altitude information from primary radar alone, and its usefulness is limited by target size and天气 conditions. This is why secondary radar (with transponder replies that include altitude data) complements primary radar in ATC.

Primary radar systems detect objects by sending out a pulse and listening for the reflection, giving you range and bearing but not direct altitude. The amount of energy reflected back depends on the target’s radar cross-section, so larger or more reflective targets produce stronger returns, while small targets can be hard to detect. Weather and atmospheric conditions—like heavy rain or ducting—also affect the signal, attenuating or distorting returns and making detection less reliable. Taken together, the key drawback is that you can’t directly obtain altitude information from primary radar alone, and its usefulness is limited by target size and天气 conditions. This is why secondary radar (with transponder replies that include altitude data) complements primary radar in ATC.