Baseline

línea basal

(line that is a base for measurement or for construction)

línea base

(engineering: something established and documented as a point of reference)

línea de base

(datum used as the basis for calculation or for comparison)

línea de fondo

(tennis: chalk line at the farthest ends of the court)

línea referencial

(datum used as the basis for calculation or for comparison)

punto de referencia

(datum used as the basis for calculation or for comparison)

punto referencial

(datum used as the basis for calculation or for comparison)

referencia

(datum used as the basis for calculation or for comparison)