Current Noise Floor

In the absence of any broadband noise sources 1 f noise or brownian noise the minimum noise level you can hope to measure in an electronic system is the thermal noise floor.

Current noise floor.

In radio communication and electronics this may include thermal noise black body cosmic noise as well as atmospheric noise from distant thunderstorms and. Generally measured in db of its maximum undistorted output signal to its residual output noise or noise floor up to 120 db of dynamic range may be required in high performance sound systems in typical homes. 19 in video systems a 50 db signal to noise ratio is a generally. In signal theory the noise floor is the measure of the signal created from the sum of all the noise sources and unwanted signals within a measurement system where noise is defined as any signal other than the one being monitored.

A skilled operator might only be able to distinguish a signal 3 db above the noise floor s n 3 db or 75 dbm. Mean noise pow er would be 174 dbm 10 log 4x10 9 174 dbm 96 db 78 dbm. A typical radar receiver would require a s n of 3 to 10 d b to distinguish the signal from noise and would require 10 to 20 db to track. Noise is naturally stronger with decreasing frequency and s meters are rarely calibrated to any standard so a s7 noise floor on 40 meters may just be ordinary.