Signal-to-noise ratio
Definition: A measure of expected source signal relative to combined statistical fluctuations and detector noise.
Why it matters here: In Observational Planning and Time Allocation, Signal-to-noise ratio is needed to reason about signal-to-noise, overheads, cadence, airmass, and scheduling rather than merely label the phenomenon.
Relationship: It is interpreted alongside Exposure time and the lecture relation below; identify which quantities are observed, calibrated, or model-derived.
Limitation or common confusion: This is a planning example, not an observatory performance claim.
\(SNR=S t/sqrt((S+B)t+n_pix RN^2)\)
Exposure time
Definition: The interval over which usable signal is accumulated after accounting for interruptions and screening.
Why it matters here: In Observational Planning and Time Allocation, Exposure time is needed to reason about signal-to-noise, overheads, cadence, airmass, and scheduling rather than merely label the phenomenon.
Relationship: It is interpreted alongside Overhead and the lecture relation below; identify which quantities are observed, calibrated, or model-derived.
Limitation or common confusion: This is a planning example, not an observatory performance claim.
Overhead
Definition: Time required for acquisition, readout, slewing, configuration, or calibration rather than science integration.
Why it matters here: In Observational Planning and Time Allocation, Overhead is needed to reason about signal-to-noise, overheads, cadence, airmass, and scheduling rather than merely label the phenomenon.
Relationship: It is interpreted alongside Cadence and the lecture relation below; identify which quantities are observed, calibrated, or model-derived.
Limitation or common confusion: This is a planning example, not an observatory performance claim.
Cadence
Definition: The timing and spacing of repeated observations relative to source variability.
Why it matters here: In Observational Planning and Time Allocation, Cadence is needed to reason about signal-to-noise, overheads, cadence, airmass, and scheduling rather than merely label the phenomenon.
Relationship: It is interpreted alongside Airmass and the lecture relation below; identify which quantities are observed, calibrated, or model-derived.
Limitation or common confusion: This is a planning example, not an observatory performance claim.
Airmass
Definition: The approximate atmospheric path length relative to zenith that affects extinction and image quality.
Why it matters here: In Observational Planning and Time Allocation, Airmass is needed to reason about signal-to-noise, overheads, cadence, airmass, and scheduling rather than merely label the phenomenon.
Relationship: It is interpreted alongside Signal-to-noise ratio and the lecture relation below; identify which quantities are observed, calibrated, or model-derived.
Limitation or common confusion: This is a planning example, not an observatory performance claim.