Time-series optical data extending back to the 1970's presents a unique capability to monitor the changing extent of the world's forest resources [1]. Coupled with more recent radar imagery, an operational forest monitoring system that provides long-term, continuous forest measurement and exploits the technical advantages of both sensors is a desirable outcome. To realise this goal, robust and repeatable methods of estimating forest stocks at national scale are required. Standardised methods of linking remote sensing data and forest inventory, generating forest information products, and evaluating and reporting mapping accuracy, are essential to alleviating the high uncertainty in forest cover change estimates [2]. This in turn will facilitate more accurate determination of emissions from forest and land cover change, and so contribute to individual countries' Measurement, Verification and Reporting (MRV) systems and input to UNFCCC REDD agreements [3].