Glycolaldehyde (HOCH2CHO) is a sugar-related interstellar prebiotic molecule that has been detected in two star-forming regions, Sgr B2(N) and G31.41+0.31. Glycolaldehyde is suspected to form from photodissociation-driven ice chemistry, and therefore can be used to trace complex organic chemistry in interstellar environments. The relative abundance of glycolaldehyde to its structural isomers, methyl formate (HCOOCH3) and acetic acid (CH3COOH), can be used to constrain astrochemical models. Given its central role in the complex chemistry of the interstellar medium, glycolaldehyde has been suggested as a prime molecular target for upcoming high-frequency molecular line searches using new far-infrared observatories. In particular, glycolaldehyde is a target for the Herschel Space Observatory HEXOS Key Program, which is conducting spectral line surveys of the Sgr B2(N) and Orion KL star-forming regions across the entire HIFI band. Laboratory investigation of glycolaldehyde in the HIFI frequency range is required before its lines can be identified in these spectra. We have therefore acquired the laboratory spectrum of glycolaldehyde in selected frequency ranges across the submillimeter range. We present here the laboratory spectral analysis of the ground vibrational state of glycolaldehyde up to 1.2 THz.