# A Police and Insurance Joint Management System Based on High Precision BDS/GPS Positioning
## 2 Related Work  
This article focuses on designing a rapid traffic accident disposal scheme based on high precision positioning, which is further developed from our previous work [6]. As the pseudo-range and Doppler measurements are usually used in the GNSS vehicle navigation system, the high-end and expensive systems can achieve real-time positioning accuracy of less than 3 m. However, the cost is too high for ordinary vehicles which only need a primary navigation module [2; 3]. With the evolution of GNSSs, there are increasingly systems and enhancement algorithms for positioning technology available, and the positioning accuracy of low-cost, single-frequency GNSS receivers has been improved to a certain extent [7]. We can obtain a 4-6 cm accuracy level in real-time stand-alone positioning if a CORSs network is used [4; 5; 8]. This equipment uses wide area real-time PPP positioning technology. Meanwhile, it obtains enhancement data broadcast by the Chinese Beidou- based augmentation system, including precise orbit data and precision clock difference data. On this basis, the positioning accuracy has been improved to sub-meter level. Our scheme is realized through a low-cost intelligent terminal, which mainly relies on single-frequency PPP technology and supplements by RTK. The external navigation patch antenna of the terminal is installed in the front of the vehicle. Additionally, as a consumer electronic product, it applies dual-mode single-frequency BDS/GPS positioning chip and an ordinary inertial navigation sensor thus the total cost of the positioning component is less than $20. From the obtained data of vehicle behaviors, the Usage-Based Insurance (UBI) vehicle insurance market in the United States and Europe has developed relatively maturely. They have a scheme to obtain data mainly realized by On-Board Diagnostics (OBD) models. As far as we know, Progressive Insurance is the first to obtain vehicle behaviors' data based on OBD. It can record real time traffic data by inserting an OBD box in a car. For example, Insure The Box, an insurance company in UK that was founded in 2010, focuses on selling insurance products based on vehicle behaviors. It owns a number of OBD-based vehicle insurance patents. At present, most products in the domestic and foreign market generally use OBD interfaces to obtain vehicle data [9; 10]. However, obtaining traffic data through OBD has several deficiencies as follows: (1) as the ordinary fault codes account for a small part of the total fault codes, identifying the vehicle information using the standard OBD-II interface it is very limited; (2) the installation of OBD products is very troublesome; (3) currently, OBD products obtain trouble codes mainly by Can-bus so technologies to crack the Can-bus private protocol of the original car are needed, which will result in information security risks and legal issues. Therefore, many researchers have put forward non-OBD models to obtain vehicle behaviors, namely, to use external sensors (such as smart phones) to collect driving behavior data [9]. For example: some researchers propose to use mobile phone sensors to detect the car's driving state, and design a way to measure driving performance indicators [11]. Others propose a framework to detect hazardous vehicle turning by using a silent Kalman filter based on the application of the GNSS measurement, and they apply it into the application of remote insurance information processing [12]. They also design a framework to deploy measurement systems based on smart phones for the application of road vehicle traffic detection and UBI vehicle insurance [13]. Moreover, some researchers analyze output data of video sensors and GPS sensors to evaluate possible risky behavior of car drivers and quality of the public transport service [14; 15]. It is easy to get driving information such as location and speed from external sensors. What's more, this can also avoid the difficulty of installing data acquisition equipment and other issues.