Real-time GPS/Galileo precise point positioning

精密单点定位（PPP）是一种不断发展的技术，它采用单个全球导航卫星系统（GNSS）接收机。经证明，PPP能够分别在静态和动态模式下提供分米级和分米级精度的定位解决方案。然而，不幸的是，目前PPP解决方案需要大约20分钟才能收敛到分米级的精度。这反过来又减缓了许多用户对该技术的采用。 Tulloch工程公司是一家设在安大略省的地理信息咨询公司，目前正在从事许多定位活动。该公司基本上依赖于通过虚拟参考站（VRS）技术提供的实时定位服务。然而，不幸的是，安大略的VRS系统的覆盖范围仅限于该省的一个小区域。当VRS系统不可用时，Tulloch使用PPP技术，尽管目前其解收敛缓慢。为了提高公司的生产力，Tulloch Engineering有意采用一种技术，在不影响定位精度的情况下减少PPP收敛时间。拟议的研究的主要目标是开发实时GPS/伽利略PPP的算法和估计方法。这又要求模糊度参数在运行中被固定到其正确的整数值。然而，实现这一点的主要问题是接收器和卫星的存在 未校准的硬件延迟。为了克服这个问题，改进的精确的卫星产品和校准的硬件延迟应生产和应用到PPP模式。由于加拿大大部分高纬度地区没有GNSS VRS网络，实时GPS/Galileo PPP可以成为精确定位应用的解决方案。因此，项目的结果将提高Tulloch工程公司（和其他加拿大公司）的生产力、效率和运营成本。其他行业，如采矿和近海，也将受益于开发的技术。该项目还将促进加拿大作为创新技术的技术中心的科学卓越性。

Precise point positioning (PPP) is an evolving technique, which employs a single global navigation satellite system (GNSS) receiver. PPP proved to be capable of providing positioning solution at the sub-decimeter and decimeter-level accuracy in static and kinematic modes, respectively. Unfortunately, however, at present the PPP solution takes approximately 20 minutes to converge to a decimeter-level accuracy. This in turn slows down the adoption of the technique by many users. Tulloch Engineering, an Ontario-based geomatics consultancy firm, is currently engaged in many positioning activities. The company relies essentially on the real-time positioning service through the virtual reference station (VRS) technique. Unfortunately, however, the coverage of Ontario's VRS systems is limited to a small region of the province. When VRS system is unavailable, Tulloch uses the PPP technique, despite its slow solution convergence at present. To increase the company's productivity, Tulloch Engineering is interested in adopting a technique that reduces the PPP convergence time without affecting the positioning accuracy. The major objective of the proposed research is to develop algorithms and estimation methodologies for real-time GPS/Galileo PPP. This in turn requires that the ambiguity parameters be fixed to their correct integer values on the fly. A major problem to realize this, however, is the presence of the receiver and the satellite un-calibrated hardware delays. To overcome this problem, improved precise satellite products and calibrated hardware delays should be produced and applied to the PPP model. As most of Canada's high latitude regions have no GNSS VRS networks, real-time GPS/Galileo PPP can be the solution for precise positioning application. As such, the outcome of project will increase the productivity, efficiency and operation cost for Tulloch Engineering (and other Canadian companies). Other industries, such as mining and offshore, will also benefit from the developed technique. The project will also contribute to the scientific excellence of Canada as a technological hub for innovative techniques.