FPGA-based software defined radio technologies for GNSS receiver design

约克大学和COM DEV团队此前曾在NSERC参与资助下合作开发软件定义无线电（SDR）星载全球导航卫星系统（GNSS）接收机。当前的应用程序通过提出开发一种原型SDR GNSS接收器来继续进行，该接收器能够跟踪从地球表面反射的GNSS信号并区分土壤含水量的变化。COM DEV认为，携带这种商业化有效载荷的未来纳米卫星/微卫星任务具有巨大潜力，可用于低成本、近实时、区域或全球近地表土壤水分含量测定，并为包括气候科学家、农民和决策者在内的许多用户带来好处。主要的科学问题是利用反射的GNSS信号遥感近地表土壤湿度变化的能力。考虑到这个问题的复杂性，目标将只是区分不同土壤含水量的信号返回差异，而不是进行校准估计。具体的研究问题是：1)确定该GNSS反射测量系统的规格和组件，包括：天线、RD前端、GNSS接收机组件和测量处理算法；2)设计基于fpga的SDR GNSS反射接收机；3)对开发的系统进行测试和调试。由此产生的用于土壤水分含量的GNSS反射接收器原型的潜在价值可能是COM DEV公司在国内和出口市场销售的可商业化空间产品。约克大学与COM DEV的伙伴关系为开发一系列新的星载卫星导航产品和服务提供了潜力。

The York University and COM DEV team has previously worked together on an NSERC Engage grant to develop a software defined radio (SDR) spaceborne Global Navigation Satellite System (GNSS) receiver. The current application follows-on by proposing the development of a prototype SDR GNSS receiver capable of tracking GNSS signals reflected from the Earth's surface and to distinguish variations in soil moisture content. COM DEV sees the significant potential of a future nanosatellite / microsatellite mission carrying such a commercialized payload for low-cost, near-real-time, regional or global near-surface soil moisture content determination, and the benefits for a host of users, including climate scientist, farmers, and policy-makers.The primary scientific issue is the ability to remotely sense near-surface soil moisture variations with reflected GNSS signals. Given the complexity of this problem, the goal will be to only distinguish differences in signal returns for different soil moisture content, rather than to make calibrated estimates.The specific research problems are 1) identiying the specifications and components for such a GNSS reflectometry system, including: antennas, RD front-end, GNSS receiver components, and measurement processing algorithms; 2) designing the FPGA-based SDR GNSS reflectometry receiver; and 3) testing and tuning the developed system.The potential value of the resulting prototype GNSS reflectometry receiver for soil moisture content could be a commercializable space product for COM DEV to sell domestically and for the export market. The York University partnership with COM DEV offers the potential to develop a family of new spaceborne satellite navigation products, as well as services.