photon shot noise
Definition: Photon shot noise denotes the physical quantity, process, or instrument component captured by this lecture-specific statement: Photon shot noise follows Poisson statistics: for a mean signal of S electrons, the standard deviation of repeated measurements is √S electrons, a fundamental floor set by the discreteness of photon detection, not by any instrumental imperfection.
Why it matters here: Lecture 04 established how a detector converts photons into a signal; this lecture establishes why that signal is never perfectly known, only measured with some uncertainty. Every signal-to-noise calculation in Lecture 06, every calibration decision in Lecture 07, and every error budget in Lecture 13 traces back to the three...
Relationships: It is used with dark current to interpret the lecture model. The quantitative connection is the working relation \(\sigma_{\rm shot} = \sqrt{S}, \qquad \sigma_{\rm dark} = \sqrt{D\,t}, \qquad \sigma_{\rm total}^{2} = S + D t + \sigma_{\rm read}^{2}\).
Boundary or common confusion: Assuming a "noisier-looking" detector reading is always due to read noise. A bright source’s own photon shot noise can dominate the total noise budget even on an otherwise very low-noise detector; distinguishing which term dominates requires the explicit calculation in this lecture’s equation, not a qualitative impression of image graininess.
dark current
Definition: Dark current denotes the physical quantity, process, or instrument component captured by this lecture-specific statement: Dark current arises from thermally generated electron-hole pairs in the detector’s silicon, indistinguishable from photon-generated charge once collected in a pixel; because thermal generation rate depends exponentially on temperature, cooling a detector by tens of degrees can suppress...
Why it matters here: Lecture 04 established how a detector converts photons into a signal; this lecture establishes why that signal is never perfectly known, only measured with some uncertainty. Every signal-to-noise calculation in Lecture 06, every calibration decision in Lecture 07, and every error budget in Lecture 13 traces back to the three...
Relationships: It is used with photon shot noise, read noise to interpret the lecture model. The quantitative connection is the working relation \(\sigma_{\rm shot} = \sqrt{S}, \qquad \sigma_{\rm dark} = \sqrt{D\,t}, \qquad \sigma_{\rm total}^{2} = S + D t + \sigma_{\rm read}^{2}\).
Boundary or common confusion: Assuming a "noisier-looking" detector reading is always due to read noise. A bright source’s own photon shot noise can dominate the total noise budget even on an otherwise very low-noise detector; distinguishing which term dominates requires the explicit calculation in this lecture’s equation, not a qualitative impression of image graininess.
read noise
Definition: Read noise denotes the physical quantity, process, or instrument component captured by this lecture-specific statement: Read noise is the electronic uncertainty introduced by the output amplifier and downstream electronics each time a pixel’s charge is measured, essentially independent of exposure time or signal level; CMOS/infrared-array detectors, which read each pixel through an individual amplifier...
Why it matters here: Lecture 04 established how a detector converts photons into a signal; this lecture establishes why that signal is never perfectly known, only measured with some uncertainty. Every signal-to-noise calculation in Lecture 06, every calibration decision in Lecture 07, and every error budget in Lecture 13 traces back to the three...
Relationships: It is used with dark current, CMOS detector to interpret the lecture model. The quantitative connection is the working relation \(\sigma_{\rm shot} = \sqrt{S}, \qquad \sigma_{\rm dark} = \sqrt{D\,t}, \qquad \sigma_{\rm total}^{2} = S + D t + \sigma_{\rm read}^{2}\).
Boundary or common confusion: Assuming a "noisier-looking" detector reading is always due to read noise. A bright source’s own photon shot noise can dominate the total noise budget even on an otherwise very low-noise detector; distinguishing which term dominates requires the explicit calculation in this lecture’s equation, not a qualitative impression of image graininess.
CMOS detector
Definition: Cmos detector denotes the physical quantity, process, or instrument component captured by this lecture-specific statement: Read noise is the electronic uncertainty introduced by the output amplifier and downstream electronics each time a pixel’s charge is measured, essentially independent of exposure time or signal level; CMOS/infrared-array detectors, which read each pixel through an individual amplifier...
Why it matters here: Lecture 04 established how a detector converts photons into a signal; this lecture establishes why that signal is never perfectly known, only measured with some uncertainty. Every signal-to-noise calculation in Lecture 06, every calibration decision in Lecture 07, and every error budget in Lecture 13 traces back to the three...
Relationships: It is used with read noise, HgCdTe infrared array to interpret the lecture model. The quantitative connection is the working relation \(\sigma_{\rm shot} = \sqrt{S}, \qquad \sigma_{\rm dark} = \sqrt{D\,t}, \qquad \sigma_{\rm total}^{2} = S + D t + \sigma_{\rm read}^{2}\).
Boundary or common confusion: Assuming a "noisier-looking" detector reading is always due to read noise. A bright source’s own photon shot noise can dominate the total noise budget even on an otherwise very low-noise detector; distinguishing which term dominates requires the explicit calculation in this lecture’s equation, not a qualitative impression of image graininess.
HgCdTe infrared array
Definition: Hgcdte infrared array denotes the physical quantity, process, or instrument component captured by this lecture-specific statement: Read noise is the electronic uncertainty introduced by the output amplifier and downstream electronics each time a pixel’s charge is measured, essentially independent of exposure time or signal level; CMOS/infrared-array detectors, which read each pixel through an individual amplifier...
Why it matters here: Lecture 04 established how a detector converts photons into a signal; this lecture establishes why that signal is never perfectly known, only measured with some uncertainty. Every signal-to-noise calculation in Lecture 06, every calibration decision in Lecture 07, and every error budget in Lecture 13 traces back to the three...
Relationships: It is used with CMOS detector, thermal generation to interpret the lecture model. The quantitative connection is the working relation \(\sigma_{\rm shot} = \sqrt{S}, \qquad \sigma_{\rm dark} = \sqrt{D\,t}, \qquad \sigma_{\rm total}^{2} = S + D t + \sigma_{\rm read}^{2}\).
Boundary or common confusion: Assuming a "noisier-looking" detector reading is always due to read noise. A bright source’s own photon shot noise can dominate the total noise budget even on an otherwise very low-noise detector; distinguishing which term dominates requires the explicit calculation in this lecture’s equation, not a qualitative impression of image graininess.
thermal generation
Definition: Thermal generation denotes the physical quantity, process, or instrument component captured by this lecture-specific statement: Dark current arises from thermally generated electron-hole pairs in the detector’s silicon, indistinguishable from photon-generated charge once collected in a pixel; because thermal generation rate depends exponentially on temperature, cooling a detector by tens of degrees can suppress...
Why it matters here: Lecture 04 established how a detector converts photons into a signal; this lecture establishes why that signal is never perfectly known, only measured with some uncertainty. Every signal-to-noise calculation in Lecture 06, every calibration decision in Lecture 07, and every error budget in Lecture 13 traces back to the three...
Relationships: It is used with HgCdTe infrared array, correlated double sampling to interpret the lecture model. The quantitative connection is the working relation \(\sigma_{\rm shot} = \sqrt{S}, \qquad \sigma_{\rm dark} = \sqrt{D\,t}, \qquad \sigma_{\rm total}^{2} = S + D t + \sigma_{\rm read}^{2}\).
Boundary or common confusion: Assuming a "noisier-looking" detector reading is always due to read noise. A bright source’s own photon shot noise can dominate the total noise budget even on an otherwise very low-noise detector; distinguishing which term dominates requires the explicit calculation in this lecture’s equation, not a qualitative impression of image graininess.
correlated double sampling
Definition: Correlated double sampling denotes the physical quantity, process, or instrument component captured by this lecture-specific statement: Photon shot noise follows Poisson statistics: for a mean signal of S electrons, the standard deviation of repeated measurements is √S electrons, a fundamental floor set by the discreteness of photon detection, not by any instrumental imperfection.
Why it matters here: Lecture 04 established how a detector converts photons into a signal; this lecture establishes why that signal is never perfectly known, only measured with some uncertainty. Every signal-to-noise calculation in Lecture 06, every calibration decision in Lecture 07, and every error budget in Lecture 13 traces back to the three...
Relationships: It is used with thermal generation to interpret the lecture model. The quantitative connection is the working relation \(\sigma_{\rm shot} = \sqrt{S}, \qquad \sigma_{\rm dark} = \sqrt{D\,t}, \qquad \sigma_{\rm total}^{2} = S + D t + \sigma_{\rm read}^{2}\).
Boundary or common confusion: Assuming a "noisier-looking" detector reading is always due to read noise. A bright source’s own photon shot noise can dominate the total noise budget even on an otherwise very low-noise detector; distinguishing which term dominates requires the explicit calculation in this lecture’s equation, not a qualitative impression of image graininess.