This research applies advanced video compression techniques to High Definition Television (HDTV) signals for transmission over 44 Mb/s facilities. The research assesses the applicability of image compression techniques, especially the Discrete Cosine Transform, to compression of the 3MHz "Augmentation Channel" used in the spectrum-compatible two-channel schemes proposed to the FCC for radio frequency transmission of HDTV. The primary tool is computer simulation of HDTV motion images in non-real time using VAX minicomputers. Simulation allows insight into which proposed systems lend themselves best to digital compression, and learning what bitrates are required to achieve good performance as measured by MSE and subject analysis of artifacts. Algorithmic changes and inventions are made in response to the initial findings, with additional simulations to further develop the knowledge base. A final step is to use the results, plus existing knowledge of compression for the NTSC-compatible channel, to estimate the available facility bitrate of 44 Mb/s.***