Applying Astronomy Capability to Map an Invasive Weed: Leveraging Satellite Surveys to Inform "Famine Weed" Policy in Pakistan It is projected that food demand will more than double by 2050 due to climate changes. The new generation of Earth observation data, including the Sentinel missions, offer the potential to identify and counteract crop yield declines. Astronomers are experts in analysing large multiband imaging surveys by making sense of the plethora of information using smaller targeted observations at high resolution and/or with spectroscopic information. This is exactly the expertise needed to utilise these new Earth observations to address global food security challenges. In this proposal, for the first time, we build crossover capabilities by focussing on a critical threat to two of the four most important crops in Pakistan (>75% of total output). Beyond the specific outputs of this project, this multi-disciplinary collaboration between astronomy, Earth observations and food security will also deliver transformative open-source tools. They will have secondary benefits to the UK in addressing global food security, and could be applied to challenges such as blackgrass in wheat. Furthermore they showcase the huge potential of STFC capabilities to contribute to tackling global challenges.  Food security in Pakistan is reliant on its ability to produce wheat and rice. A new invasive species of weed, the "Famine Weed" (Parthenium hysterophorus), has been identified as a critical threat to agriculture and human prosperity in the region. Parthenium affects crop yields by as much as 90%, and has serious impacts on human and livestock health, and is therefore this project is of great importance to Pakistan. The University of Manchester and the Centre for Agriculture and Bioscience International (CABI) have joined forces to define a key challenge area for STFC research: the use of astronomy image analysis for mapping Parthenium across Pakistan. With their Islamabad office, CABI have over sixty years of on-the-ground experience in Pakistan and a proven track record of undertaking agricultural research projects in this region. Combined with the world-leading expertise in astronomy image analysis and optical instrumentation engineering at Manchester, we propose a four-stage project to provide detailed mapping of Parthenium in wheat and rice agriculture for the major arable regions of Pakistan.  Initially, we will aggregate and preprocess multispectral satellite imagery (WP1) and implement a campaign to collect high quality ground reference data (WP2) which is currently lacking. These will be combined to produce a computing framework for the detection of Parthenium in crops across the country. This will deliver static maps for the current extent of the weed (WP3) as well as a mechanism for future monitoring to be adopted by policy makers (WP4). We also place a strong emphasis on local academic capacity building through employment of local researchers, delivery of technical workshops, data hack challenge events and a researcher exchange program between Manchester and universities in Punjab (WP4).  Impact is achieved via three interlinked outcomes: 1) Policy makers become aware of and able to use satellite data for decision-making in agriculture, livestock, and human health; 2) Improved methods allow for automated mapping and monitoring of the distribution of Parthenium in rice and wheat fields; and 3) Pakistani researchers develop strengthened capacities in their fields that contribute to their ongoing work. The Global Challenges Research Fund (GCRF) supports cutting-edge research to address challenges faced by developing countries. The fund addresses the UN sustainable development goals. It aims to maximise the impact of research and innovation to improve lives and opportunity in the developing world.