(indication of how far a survey reaches)
The phrase survey depth indicates how far an astronomical survey
reaches, but is cited using different measures. The obvious measure
of distance (parsecs or light-years) is probably most often used for
explanations for public consumption, e.g., news releases.
- largest apparent magnitude number reached, often specifying bands.
- exposure time, i.e., length of time used to image each part of the survey field, using measures of seconds (or kiloseconds), hours, or days, or sometimes for space observatories, orbits.
- highest redshift reached or targeted.
deep field (DF)