SBIR Phase I: Low Earth Orbit Navigation System (LEONS) - The Ground Network

这项小企业创新研究（SBIR）第一阶段项目的更广泛影响/商业潜力是使美国关键的基础设施减少对全球定位系统（GPS）的依赖。交通运输业、电网、银行业务和通信系统都是相互关联的，并且严重依赖GPS进行准确可靠的定位或时间同步。该项目通过提供完全独立于GPS的精确定位和定时来解决这一单点故障。此外，新兴的自动驾驶汽车市场需要一个比GPS单独提供的更可靠的定位、导航和授时（PNT）系统，以充分发挥市场潜力。解决GPS信号干扰和欺骗的已知痛点将提高车辆安全性，并提高消费者对自动驾驶汽车、包裹递送无人机、自动搜索和救援等自动驾驶应用的信心。这种影响将增加自动驾驶汽车制造商和支持技术公司的销售，如传感器、电池和计算机芯片制造商。这个小企业创新研究（SBIR）第一阶段项目研究了使用地面站网络接收从未为PNT设计的低地球轨道（LEO）卫星信号并将其转换为PNT可用信号的可行性。数千颗低轨道卫星被发射到太空，用于互联网和通信。然而，与为提取PNT测量而设计的GPS信号结构不同，从通信和互联网LEO卫星传输的信号结构从未用于PNT。GPS卫星向GPS接收器传送精确的卫星星历、大气和时钟信息，而LEO卫星通常无法获得这些信息。该项目建议部署一个地面网络，从近地轨道卫星信号中确定这些信息，并使这些信息可用于PNT目的。为此，本项目涉及以下研究重点：1)找到地面站的最佳几何分布，以最大限度地减少LEO卫星星历、时钟和大气误差；2)开发特殊的信号处理和估计理论技术，从现有和未来的LEO卫星信号中免费提取准确的PNT测量值（无需订阅其网络）；3)在使用地面网络产生的信息时，推导出PNT估计误差的理论限制。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

The broader impact/commercial potential of this Small Business Innovation Research (SBIR) Phase I project is to make critical United States infrastructure less dependent on the Global Positioning System (GPS). The transportation industry, power grid, banking operations, and communication systems are all interconnected and heavily rely on GPS for accurate and reliable positioning or time synchronization. This project addresses this single point of failure by providing accurate positioning and timing, completely independent of GPS. Additionally, the emerging autonomous vehicle market requires a more reliable positioning, navigation, and timing (PNT) system than GPS can provide alone for the market to reach full potential. Addressing the known pain points of GPS signal jamming and spoofing will improve vehicle safety and consumer confidence in autonomous applications ranging from self-driving cars, and package delivery drones, to autonomous search and rescue. This impact will increase sales for autonomous vehicle manufactures and supporting technology companies, such as sensor, battery, and computer chip manufacturers. This Small Business Innovation Research (SBIR) Phase I project studies the feasibility of using a network of ground stations to receive low Earth orbit (LEO) satellite signals that were never designed for PNT and convert them into PNT-usable signals. Thousands of LEO satellites are being launched into space for internet and communication. However, unlike the GPS signal structure designed for extraction of PNT measurements, the signal structure transmitted from communication and internet LEO satellites was never intended for PNT. GPS satellites transmit accurate satellite ephemeris, atmospheric, and clock information to the GPS receiver, whereas this information is typically unavailable for LEO satellites. This project proposes to deploy a ground network to determine this information from LEO satellite signals and make this information available for PNT purposes. To this end, this project involves the following research thrusts: 1) find the optimal geometric distribution of the ground stations to minimize LEO satellite ephemeris, clock, and atmospheric errors, 2) develop special signal processing and estimation theory techniques to extract accurate PNT measurements from existing and future LEO satellite signals for free (without a subscription to their network), and 3) derive theoretical limits on PNT estimation errors when using the ground network’s produced information.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.