局域增强系统(L oca l A rea A ugm en ta tion System,LAA S)是美国联邦航空局(F ed era l A v ia tion A d-m in istra tion,FAA)开发的G PS地基增强系统,支持G PS差分精密进近和着陆.多基准一致性检测是LAA S地面完好性监测的核心算...局域增强系统(L oca l A rea A ugm en ta tion System,LAA S)是美国联邦航空局(F ed era l A v ia tion A d-m in istra tion,FAA)开发的G PS地基增强系统,支持G PS差分精密进近和着陆.多基准一致性检测是LAA S地面完好性监测的核心算法.多基准一致性检测通过对伪距校正误差的测试和评估,保证了LAA S地面系统发布的伪距校正量误差不超出一个给定的范围.本文详细讨论了LAA S完好性监测模型中多基准一致性检测算法的B值的含义,并通过实验分析了B值的范围和阈值的选取.结果表明:在正常无故障情况下,B值的大小稳定在一个较小的范围内变化.一旦发生故障,通过阈值的限制就能检测出B值异常的情况.展开更多
It has been proven that carrier smoothing and differential global positioning system （DGPS） are effective to improve the accuracy of pseudorange by reducing the noise in it and eliminating almost all the common mode...It has been proven that carrier smoothing and differential global positioning system （DGPS） are effective to improve the accuracy of pseudorange by reducing the noise in it and eliminating almost all the common mode errors between the ground station and user. However, another issue coming with local area augmentation system （LAAS） is how to find an adaptive smoothing window width to minimize the error on account of ionosphere delay and multipath. Based on the errors analysis in carrier smoothing process, a novel algorithm is formulated to design adaptive Hatch filter whose smoothing window width flexibly varies with the characteristic of ionosphere delay and multipath in the differential carrier smoothing process. By conducting the simulation in LAAS and after compared with traditional Hatch filers, it reveals that not only the accuracy of differential correction, but also the accuracy and the robustness of positioning results are significantly improved by using the designed adaptive Hatch filter.展开更多
文摘局域增强系统(L oca l A rea A ugm en ta tion System,LAA S)是美国联邦航空局(F ed era l A v ia tion A d-m in istra tion,FAA)开发的G PS地基增强系统,支持G PS差分精密进近和着陆.多基准一致性检测是LAA S地面完好性监测的核心算法.多基准一致性检测通过对伪距校正误差的测试和评估,保证了LAA S地面系统发布的伪距校正量误差不超出一个给定的范围.本文详细讨论了LAA S完好性监测模型中多基准一致性检测算法的B值的含义,并通过实验分析了B值的范围和阈值的选取.结果表明:在正常无故障情况下,B值的大小稳定在一个较小的范围内变化.一旦发生故障,通过阈值的限制就能检测出B值异常的情况.
基金supported by the National Natural Science Foundationof China (60974104)the National Defense Technical Foundation of Shipbuilding Industry (08J3.8.8)
文摘It has been proven that carrier smoothing and differential global positioning system （DGPS） are effective to improve the accuracy of pseudorange by reducing the noise in it and eliminating almost all the common mode errors between the ground station and user. However, another issue coming with local area augmentation system （LAAS） is how to find an adaptive smoothing window width to minimize the error on account of ionosphere delay and multipath. Based on the errors analysis in carrier smoothing process, a novel algorithm is formulated to design adaptive Hatch filter whose smoothing window width flexibly varies with the characteristic of ionosphere delay and multipath in the differential carrier smoothing process. By conducting the simulation in LAAS and after compared with traditional Hatch filers, it reveals that not only the accuracy of differential correction, but also the accuracy and the robustness of positioning results are significantly improved by using the designed adaptive Hatch filter.
