The terahertz spectrum, often defined as the 300GHz-3THz frequency band, is a relatively unexplored segment of the electromagnetic spectrum, lying between the microwave and far infrared regions. Although measurement capabilities at these frequencies are just now being realized, there are already numerous applications such as imaging, spectroscopy, radio astronomy, and medical diagnostics[1]. To support this growing industry, a proper measurement infrastructure is needed, similar to what is currently available at 100 GHz and below. Efforts to develop the hardware[2, 3] and components[4, 5] needed to realize this measurement infrastructure are being made. Complementary to these advances in new hardware, specialized measurement procedures and improved calibration algorithms are being created[6, 7]. This work presents contributions to the field of terahertz metrology, specifically to the area of calibration and uncertainty analysis. i List of Tables 1.1. Companies and research laboratories that are involved with terahertz