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. Signal theory is the theory of the engineering discipline of signal processing. ... In general usage, noise can be considered data without meaning; that is, data that is not being used to transmit a signal, but is simply produced as an unwanted by-product of other activities. ...
In radio communication and electronics, this may include thermal noise, blackbody, and any other interfering signals. In a measurement system such as a seismograph, it may include nearby foot traffic or a nearby road. The noise floor limits the smallest measurement that can be taken since any measured amplitude can be no less than the noise floor. Johnson-Nyquist noise (sometimes thermal noise, Johnson noise or Nyquist noise) is the noise generated by the equilibrium fluctuations of the electric current inside an electrical conductor, which happens without any applied voltage, due to the random thermal motion of the charge carriers (the electrons). ... As the temperature decreases, the peak of the black body radiation curve moves to lower intensities and longer wavelengths. ... Seismographs (in Greek seismos = earthquake and graphein = write) are used by seismologists to record seismic waves. ...
A common way to lower the noise floor in electronics systems is to cool the system to reduce thermal noise, which is usually the major noise source.
In signal theory, the noisefloor is the measure of the signal created from the sum of all the noise sources and unwanted signals within a measurement system.
The noisefloor limits the smallest measurement that can be taken since any measured amplitude can be no less than the noisefloor.
A common way to lower the noisefloor in electronics systems is to cool the system to reduce thermal noise, which is usually the major noise source.
The noisefloor is determined by the type of read circuits in the image sensor, the transistor characteristics, or imager support circuits such as the analog to digital convertor.
Good noisefloor performance is fairly easy to achieve with CCD imagers, which is one reason CCD sensors have survived in spite of inefficiencies inherent in the way CCDs extract signals from the sensor array.
This noise source, known as "photon shot noise", is proportional to the square root of the signal level.
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