That sounds reasonable. For a camera sensor, the noise budget is made up of four primary terms:
1. So called "fixed pattern noise," i.e., a pixel by pixel pattern in the measured value that isn't reduced by averaging. This pattern would be a "fingerprint" of the camera, probably long term if not forever. You can make a well averaged measurement of the fixed pattern (somewhat temperature dependent) and subtract it from subsequent exposures.
2. Thermal noise of the amplifier that converts charge into a signal that can be read by the analog-to-digital converter. This is referred to as "readout noise."
3. Shot noise in "good" photocurrent, i.e., photons from the scene being converted into charge. This becomes dominant at higher light levels, as it's proportional to the square root of photocurrent.
4. Shot noise in "bad" photocurrent, i.e., a constant leakage current in the light sensitive elements, whose magnitude is temperature dependent.
1. So called "fixed pattern noise," i.e., a pixel by pixel pattern in the measured value that isn't reduced by averaging. This pattern would be a "fingerprint" of the camera, probably long term if not forever. You can make a well averaged measurement of the fixed pattern (somewhat temperature dependent) and subtract it from subsequent exposures.
2. Thermal noise of the amplifier that converts charge into a signal that can be read by the analog-to-digital converter. This is referred to as "readout noise."
3. Shot noise in "good" photocurrent, i.e., photons from the scene being converted into charge. This becomes dominant at higher light levels, as it's proportional to the square root of photocurrent.
4. Shot noise in "bad" photocurrent, i.e., a constant leakage current in the light sensitive elements, whose magnitude is temperature dependent.