Realization and application testing of real-time kinematic on smartphone
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摘要: 随着芯片技术的发展,智能手机已成为使用最普遍的一类全球卫星导航系统(GNSS)设备,其提供位置服务的能力逐步彰显. 为探究将手机作为专业GNSS设备的可行性,利用谷歌开放Android智能终端GNSS原始观测数据这一契机,设计并实现一款手机实时动态 (RTK)定位手机应用程序(APP),并基于该APP开展高精度定位应用试验. 结果表明:在静态条件下,手机RTK定位精度约达1 dm;在行人和车载动态条件下,可达平面亚米级、高程1~2 m的精度水平,RTK定位精度远高于内置芯片解,但稳定性略差于芯片解. 使用手机模拟RTK点测量,其平面精度约达1 m,基本满足地理信息采集和调查等亚米级到米级低精度专业应用的需求.
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关键词:
- 全球卫星导航系统(GNSS) /
- 智能手机 /
- 实时动态(RTK) /
- 定位软件 /
- 应用试验
Abstract: With the development of chip technology, the smartphone has become the most widely used Global Navigation Satellite System (GNSS) device, and its ability to provide location services is gradually being demonstrated. To investigate the feasibility of using a smartphone as a professional GNSS device and to take advantage of the opportunity of opening GNSS raw measurements on an Android smart terminal, an real-time kinematic (RTK) positioning APP was designed and implemented, and a high-precision positioning application test was performed based on it. The results show that the APP's real-time positioning accuracy can achieve about 1 dm under static conditions, and can reach sub-meter levels in plane and 1 to 2 m in vertical under dynamic situations of pedestrians and automobiles. The RTK positioning accuracy is significantly higher than that of the built-in chip solution, but the stability is slightly worse. The results also show that when using a smartphone to imitate RTK point measurement, the plane accuracy can reach about 1 m, which is sufficient for sub-meter to meter-level low-precision professional applications such as geographic information collecting and survey. -
表 1 Android API中GNSS原始测量值主要字段
字段(缩写) 描述 TimeNanos(TN) 接收机内部硬件钟 BiasNanos(BN) 钟亚纳秒偏差 FullBiasNanos(FBN) 接收机钟与GPS时总偏差 ReceivedSvTimeNanos(RSTN) 卫星发射信号时间 AccumulatedDeltaRangeMeters(ADRM) 伪距增量 Cn0DbHz 载噪比(C/N0) TimeOffsetNanos(TON) 钟偏差 PseudorangeRatemetersperSecond(PRS) 伪距率 表 2 载波相位记录状态
AccumulatedDeltaRangeState 描述 0 无效或未知 1 状态有效 2 钟重启 4 发生周跳 表 3 手机RTK解算参数设置
参数 设置值 卫星系统 BDS B1/GPS L1/Galileo E1,卫星较少时
使用双频和其他系统卫星截止高度角 10° C/N0截止阈值 20 dB-Hz 随机模型 高度角+ C/N0,
伪距与载波精度比300∶1周跳探测 LLI/多普勒/伪距载波组合 模糊度 不固定 表 4 静态条件下手机RTK定位测试统计结果
m 测试设备 统计类型 RTK定位结果 内置芯片解结果 E N U E N U MI8 #1 全时段RMS 0.237 0.097 0.465 1.677 8.297 15.452 收敛后RMS 0.112 0.053 0.116 1.581 8.368 16.118 MI8 #2 全时段RMS 0.347 0.162 0.686 2.842 8.196 13.310 收敛后RMS 0.107 0.056 0.105 2.281 8.292 13.720 表 5 行人和车辆导航RMS统计
m 测试类型 手机RTK 手机芯片解 E N U E N U 行人1 0.500 0.830 1.088 0.662 3.955 1.901 行人2 0.674 0.353 1.553 0.900 0.602 2.364 车载1 0.281 0.662 1.487 1.662 1.508 3.160 车载2 0.753 0.449 0.790 0.759 0.957 2.013 表 6 手机RTK测量坐标结果
m 点号 与测量型RTK结果较差 Δx Δy Δh DA01 0.139 2.139 1.549 DA02 −0.637 −0.053 1.823 DA03 0.352 0.656 −1.519 DA04 0.033 −1.459 0.919 DA05 −1.198 −0.687 −0.217 JG01 0.721 1.378 −0.503 JG02 −1.998 2.338 2.498 JG03 −0.595 0.680 −3.011 JG04 −1.300 0.230 −4.757 JG05 1.071 0.212 −4.000 JG06 −0.089 −0.070 −4.299 JG07 −0.191 0.675 −3.608 JG08 −0.763 0.600 −2.878 JG09 0.898 −1.019 −4.019 JG10 −0.311 0.008 2.329 JG11 −0.206 −2.169 0.179 中误差 0.656 0.898 2.382 -
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