【摘要】：高精度GPS動態(tài)定位通常采用載波相位差分定位的方式，需要解決的關(guān)鍵問題是周跳探測和整周模糊度固定。然而，在城市、叢林等障礙物較多的地區(qū)進行動態(tài)測量時，GPS衛(wèi)星信號容易失鎖，多路徑等噪聲因素影響也很嚴重，這會導致周跳的頻繁發(fā)生和整周模糊度不再可靠。因此，GPS失鎖以后整周模糊度的快速恢復以及周跳的可靠探測就成了GPS高精度動態(tài)定位的重要問題，也是研究的熱點和難點。 本文基于GPS精密動態(tài)相對定位技術(shù)，系統(tǒng)研究了INS輔助GPS動態(tài)定位的兩項技術(shù)，即INS輔助整周模糊度的解算和INS輔助周跳探測。文中包含了以下工作內(nèi)容和研究成果： 1.簡要介紹了GPS動態(tài)定位的數(shù)學模型和INS的原理特點，分析了影響動態(tài)定位精度的誤差因素及改正方法。 2.系統(tǒng)研究了GPS動態(tài)定位的兩項關(guān)鍵技術(shù)，即周跳探測與處理和整周模糊度解算，并給出了利用自編的相對定位程序進行GPS動態(tài)定位解算的結(jié)果。自編程序采用雙差觀測模型，廣播星歷計算衛(wèi)星位置，組合方法探測周跳，Kalman濾波方法估計模糊度浮點解，最小二乘模糊度去相關(guān)平差法(Least-square Ambiguity Decorrelation Adjustment，LAMBDA)搜索整周模糊度以及Ratio值檢驗法確認整周模糊度。解算結(jié)果表明，相對定位程序?qū)晤lL1模糊度固定成功率在80%左右，寬巷模糊度固定成功率達到99%，模糊度固定以后單頻L1解算定位誤差的RMS小于兩個厘米，說明程序具備了較高的精度及可靠性。 3.研究了INS輔助GPS整周模糊度解算技術(shù)。文中給出了三種輔助的方法，即直接法、兩步法和全組合法，并對兩步法和全組合法的等價性進行了推導。介紹了理論上評價模糊度搜索空間及解算精度的兩個指標，即模糊度精度衰減因子(Ambiguity Dilution ofPrecision， ADOP)和模糊度解算精度提高的百分率（相對于僅有GPS數(shù)據(jù)的情況下，模糊度解算精度提高的百分率），并以此為基礎(chǔ)，通過算例分析了不同INS位置精度和輔助方法下，模糊度搜索空間及解算精度變化情況。結(jié)果表明，當INS位置精度較高時，如優(yōu)于0.2m時，模糊度搜索空間將明顯縮小，解算精度也會明顯提高，隨著INS位置精度的下降，三種方法的輔助效果都會變差，且直接法輔助效果下降更快。 4.給出了GPS不同失鎖時間及三種輔助方法下，單頻L1模糊度固定所需的時間情況。結(jié)果表明，在GPS短時間失鎖情況下，如失鎖時間小于30s，INS輔助模糊度解算能夠縮短模糊度的固定時間，，從而快速地恢復整周模糊度。 5.研究了INS輔助GPS周跳探測技術(shù)。文中基于Kalman濾波新息檢驗理論構(gòu)造周跳檢測量，運用χ~2檢驗的方法進行周跳檢驗，并利用最小可探測偏差(Minimum Detectable Bias,MDB)進行周跳的識別定位。算例分析了周跳檢測量和MDB值的特性，并運用該方法對仿真的周跳進行了探測。結(jié)果表明，該方法不僅能夠探測單周跳，而且能夠同時探測多個周跳的情況，在GPS失鎖時間為2秒時，對小到1周的周跳也能正確地探測出來。
[Abstract]:High-precision GPS dynamic positioning usually adopts carrier phase difference positioning mode, and the key problem that needs to be solved is that the round-hop detection and the whole-cycle ambiguity are fixed. However, when dynamic measurement is carried out in areas such as cities, jungles and the like, the influence of GPS satellite signals on noise factors such as lock-out and multi-path is also very serious, which can lead to the frequent occurrence of the cycle and the ambiguity of the whole-cycle ambiguity. Therefore, the fast recovery of the whole-cycle ambiguity and the reliable detection of the cycle jump are the important problems of GPS high-precision dynamic positioning after the GPS is lost, and it is also a hot point and a difficult point of the research. In this paper, based on the technology of GPS precise dynamic relative location, the two techniques of INS-assisted GPS dynamic positioning are studied, that is, the solution of the whole-cycle ambiguity of the INS and the auxiliary cycle of the INS. The following work contents and research are included in this paper. 1. The mathematical model of GPS dynamic positioning and the principle of INS are briefly introduced. The error factors and the change of the dynamic positioning accuracy are analyzed. In this paper, two key technologies of GPS dynamic positioning, namely, the weekly-hop detection and processing and the whole-cycle ambiguity resolution, are studied in this paper, and the dynamic positioning of GPS is given by using the self-designed relative positioning program. The results of the solution are as follows: The self-designed program uses the two-difference observation model, the broadcast ephemeris to calculate the satellite position, the combination method detects the cycle-hop, the Kalman filter method estimates the ambiguity-floating-point solution, the least-square-degree-of-least-square-degree-to-correlation level difference method (LAMDA) searches for the whole-cycle ambiguity, and the Ratio value test method confirms The results show that the fixed success rate of single-frequency L1 ambiguity is about 80%, the fixed success rate of the wide-lane ambiguity is 99%, and the RMS of the single-frequency L1 solution positioning error after the ambiguity is fixed is less than two centimeters. 3. The whole time of INS-assisted GPS is studied. In this paper, three kinds of auxiliary methods, namely, direct method, two-step method and all-group method, are given in this paper, and the two-step method and all-group method are also given. In this paper, the value of the fuzzy degree search space and the resolution precision are derived. The fuzzy degree precision attenuation factor (ADOP) and the percentage of the ambiguity resolution accuracy (with respect to the GPS data only) are introduced. Based on this, a numerical example is given to analyze the search space and solution of fuzzy degree with different INS position accuracy and auxiliary method. The results show that when the position accuracy of INS is high, for example, the position accuracy of INS is better than 0.2m, the fuzzy degree search space will be reduced obviously, and the resolution precision can be obviously improved. With the decrease of the INS position accuracy, the auxiliary effect of the three methods will be deteriorated, and the direct method and auxiliary method 4. The single-frequency L1 ambiguity is given under the different time of the GPS and the three kinds of auxiliary methods. The results show that the INS-assisted ambiguity resolution can shorten the fixed time of the fuzzy degree in the case of short-time lock-out of the GPS, such as the time of the lock-out time is less than 30s, so that the time is fast. Fast recovery of full-cycle ambiguity.5. Study of INS In this paper, based on the theory of Kalman filter new-interest test, the detection of the cycle-hop is constructed, and the method of 1-2 test is used to check the cycle-hop, and the minimum detectable bias (MD) is used. B) The identification and location of the peripheral hop are carried out. An example is given to analyze the characteristics of the week-hop detection and the value of the MDB, and the method is applied. The results show that the method not only can detect the single-cycle jump, but also can detect the condition of multiple cycles at the same time. When the time of the GPS lock-out time is 2 seconds, it is as small as 1 week.
【學位授予單位】：解放軍信息工程大學
【學位級別】：碩士
【學位授予年份】：2013
【分類號】：P228.4

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