sun_alt
Unit: deg (degrees)
Sun altitude above horizon at observation time. Calculated using astronomical algorithms based on UTC timestamp and geographic coordinates. Negative values indicate sun is below horizon (nighttime).
moon_alt
Unit: deg (degrees)
Moon altitude above horizon at observation time. Calculated using lunar position algorithms. Positive values indicate moon is visible above horizon.
gal_lat
Unit: deg (degrees)
Galactic latitude of zenith pointing direction. Calculated by converting horizontal coordinates (alt=90°, az=0°) to galactic coordinates. Indicates distance from galactic plane.
sd_10min
Unit: mag/arcsec²
Rolling standard deviation of MSAS over previous 10 minutes (10 measurements). Requires temporal continuity: values set to NaN if gap >3 minutes detected or insufficient data. Indicates sky brightness variability.
cloud_index
Unit: unitless
Cloud coverage indicator calculated as: 100 - (3 × (Temp - SkyTemp))
Higher values indicate cloudy conditions. Lower/negative values (<40) indicate probable clear conditions. Based on temperature differential between enclosure and sky.
solar_flux
Unit: sfu (Solar Flux Units)
Optional column. Solar Radio Flux at 10.7cm wavelength. Calculated as 3-day average of the previous 3 days only (current day excluded). Data from Space Weather Canada. Higher solar flux generally produces stronger airglow.