TABLE OF CONTENTS These problem solutions are calculated using four significant figures, where the input data supports this precision. The answers are rounded to three significant figures, since most practical radar parameters are known only to this or lesser accuracy.
| 1. | What is the time delay between transmission and reception of a radar signal when the target is at a range of 200 km from the radar? |
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| 2. | What is the radial velocity of a target producing a Doppler shift of +20 Hz (frequency increase in the returned signal), if the transmitted radar frequency is 425 MHz? |
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| 3. | What is the power ratio corresponding to a decibel level of 22 dB? |
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| 4. | What is the decibel value corresponding to a power ratio of 75? |
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| 5. | What range in kilometers is indicated by a radar pulse return that occurs 3.5 ms after the pulse transmission? |
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| 6. | For a target having a velocity of 700 m/s moving toward the radar at an angle of 30 from the radar line-of-sight (LOS), and a radar frequency of 5.5 GHz:
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| 7. | Convert 15 dB to a power ratio. |
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| 8. | Convert 0.03 m [2] to decibels relative to a square meter (dBsm). |
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Answers
| 1. | 200 km = 200 10 3 m. From (1.1), t = 2 200 10 3/(3 10 8) = 0.001333 sec ? 1.33 ms. |
