# Probability of a False Alarm: Noise Power

The fixed threshold of a radar detector was set, assuming a known noise power, to yield P_FA = 10^-6. The actual noise power was 3 dB higher than expected. What will be the actual P_FA?

© BrainMass Inc. brainmass.com October 9, 2019, 4:20 pm ad1c9bdddfhttps://brainmass.com/engineering/power-engineering/probability-false-alarm-noise-power-29260

#### Solution Preview

I will use B for the noise power, Bnom for the nominal noise power.

Actual noise ...

#### Solution Summary

If Actual noise power in dB = Nominal noise power in dB + 3, then the problem can be solved using simple a logarithmic function as shown.

$2.19