时间频率学报
時間頻率學報
시간빈솔학보
JOURNAL OF TIME AND FREQUENCY
2012年
2期
105-111
,共7页
刘利%唐桂芬%郭睿%白英广%刘晓萍%朱陵凤
劉利%唐桂芬%郭睿%白英廣%劉曉萍%硃陵鳳
류리%당계분%곽예%백영엄%류효평%주릉봉
卫星导航系统%测量%伪距%钟差%时标偏差
衛星導航繫統%測量%偽距%鐘差%時標偏差
위성도항계통%측량%위거%종차%시표편차
satellite navigation system%measurement%pseudorange%clock offset%timescale deviation
伪距是卫星导航系统的基本观测量,是实现导航定位、精密定轨和精确授时的基础。基于伪距、钟差和时标偏差的概念与定义,讨论了时标偏差对卫星伪距测量的影响特性;在此基础上,给出了利用伪距O-C(观测值与计算值之差)进行时标偏差解算的计算模型;理论分析表明:时标偏差影响主要体现在伪距变率项;对于MEO卫星,时标偏差影响不仅会使真实的O-C曲线斜率变大、曲线变长,而且会使多个弧段O-C曲线呈现锯齿状,表现为每个弧段解算的参数不能用于跨弧段预报。最后,利用北斗试验系统MEO卫星实测数据进行了验证分析,试验结果表明:采用实测数据计算的时标偏差精度约在0.02s左右,不同弧段解算结果比较稳定,并且扣除时标偏差后的O-C计算结果也与理论结果具有较好的一致性,从而验证了本文时标偏差理论分析和计算模型的正确性。
偽距是衛星導航繫統的基本觀測量,是實現導航定位、精密定軌和精確授時的基礎。基于偽距、鐘差和時標偏差的概唸與定義,討論瞭時標偏差對衛星偽距測量的影響特性;在此基礎上,給齣瞭利用偽距O-C(觀測值與計算值之差)進行時標偏差解算的計算模型;理論分析錶明:時標偏差影響主要體現在偽距變率項;對于MEO衛星,時標偏差影響不僅會使真實的O-C麯線斜率變大、麯線變長,而且會使多箇弧段O-C麯線呈現鋸齒狀,錶現為每箇弧段解算的參數不能用于跨弧段預報。最後,利用北鬥試驗繫統MEO衛星實測數據進行瞭驗證分析,試驗結果錶明:採用實測數據計算的時標偏差精度約在0.02s左右,不同弧段解算結果比較穩定,併且釦除時標偏差後的O-C計算結果也與理論結果具有較好的一緻性,從而驗證瞭本文時標偏差理論分析和計算模型的正確性。
위거시위성도항계통적기본관측량,시실현도항정위、정밀정궤화정학수시적기출。기우위거、종차화시표편차적개념여정의,토론료시표편차대위성위거측량적영향특성;재차기출상,급출료이용위거O-C(관측치여계산치지차)진행시표편차해산적계산모형;이론분석표명:시표편차영향주요체현재위거변솔항;대우MEO위성,시표편차영향불부회사진실적O-C곡선사솔변대、곡선변장,이차회사다개호단O-C곡선정현거치상,표현위매개호단해산적삼수불능용우과호단예보。최후,이용북두시험계통MEO위성실측수거진행료험증분석,시험결과표명:채용실측수거계산적시표편차정도약재0.02s좌우,불동호단해산결과비교은정,병차구제시표편차후적O-C계산결과야여이론결과구유교호적일치성,종이험증료본문시표편차이론분석화계산모형적정학성。
The pseudorange is a basic observation in a satellite navigation system,and is the foundation of navigation and positioning,precise orbit determination and precise time transfer.According to the concepts and definitions of pseudorange,clock offset and timescale deviation,the influence of timescale deviation on the pseudorange measurement is discussed.By using the O-C(the difference between measured value and computed value) results of pseudorange measurements,a model for calculating timescale deviation is given.The academic analysis indicates that the influence of timescale deviation is mainly laid on the pseudorange changing rate.If the timescale deviation exists in the MEO satellite pseudorange measurements,the O-C curve will become longer,the slope of O-C curve will become larger,and the O-C curves of different observing arcs will become indention.As a result,the prediction parameters which are calculated with one observing arc will be wrong and can′t be used to other observing arcs.Finally,an experimental analysis is performed with the MEO satellite actual observing data of the compass navigation system.The results show that: 1) the accuracy of calculated timescale deviation is about 0.02 s;2) the timescale deviations for different observing arcs are stable;3) the O-C results with the timescale deviation removed are accordant with the theory results;4) the correctness of the academic analysis and computational model is validated.