ObsHistory

This table keeps a record of each visit made by the observatory during a simulated survey. Multiple proposals can be associated with a single visit leading to duplicate entries in this table.

Column Description
observationId Numeric identifier for an observation entry.
Session_sessionId The simulation run session Id.
night The night in the survey for the observation. Starts from 1.
observationStartTime The UTC start time for the observation (units=seconds). This occurs after the slew but before the first exposure.
observationStartMJD The Modified Julian Date at observation start (units=seconds).
observationStartLST The Local Sidereal Time at observation start (units=degrees)
TargetHistory_targetId Numeric identifier that relates to an entry in the TargetHistory entry.
Field_fieldId Numeric identifier that relates to an entry in the Field table.
groupId Group Id for the observation. This is non-zero and repeated for field/filter combinations collected in sets of N (tuples or sequences). It is zero when N equal one.
filter The one character name for the band filter.
ra The Right Ascension of the observation (units=degrees).
dec The Declination of the observation (units=degrees).
angle The Position Angle of the observation (units=degrees).
altitude The altitude of the observation (units=degrees).
azimuth The azimuth of the observation (units=degrees)
numExposures The number of exposures taken for the observation.
visitTime The total time for the observation (units=seconds) including exposure, shutter and readout time.
visitExposureTime The sum of all the exposure times for the observation (units=seconds). No shutter and readout time included.
airmass The airmass of the observation field.
skyBrightness The calculated skybrightness for the observation field.
cloud The fraction of clouds present (0: none to 1: total).
seeingFwhm500 The full-width at half-maximum for seeing observations at 500 nm at zenith.
seeingFwhmGeom “Geometrical” full-width at half-maximum, actual half width at maximum brightness. This can be used to represent the FWHM of a double Gaussian representing the physical width of a PSF.
seeingFwhmEff “Effective” full-width at half-maximum, typically ~15% larger than seeingFwhmGeom. This can be used to calculate SNR for point sources, using seeingFwhmEff as the FWHM of a single Gaussian describing the PSF.
fiveSigmaDepth The magnitude of a point source that would be a 5-sigma detection (units=magnitudes)
moonRA The right-ascension (units=degrees) of the moon.
moonDec The declination (units=degrees) of the moon.
moonAlt The altitude (units=degrees) of the moon.
moonAz The azimuth (units=degrees) of the moon.
moonDistance The distance (units=degrees) between the moon and the observation field.
moonPhase The phase of the moon.
sunRA The right-ascension (units=degrees) of the sun.
sunDec The declination (units=degrees) of the sun.
sunAlt The altitude (units=degrees) of the sun.
sunAz The azimuth (units=degrees) of the sun.
solarElong The solar elongation (units=degrees) of the observation field (distance between it and sun).