Time-differenced Methods For Estimating GPS/BDS/DORIS/SLR Observation Noise

Modern space observation technology is always influenced by the atmospheric and other aspects, such as internal thermal noise interference, mingled with the random noise in the measurement signal. In this case, this paper proposes a time-differenced method to estimate the measurement noise and researches the tendency between observation precision and satellite azimuth based on the observations of GPS/BDS/DORIS/SLR. The main contents and results of the dissertation are shown below:(1) Basic theory: this paper analyzes the composition and characteristic of GPS/BDS/ DORIS/SLR, introduces the observation equation as well as the main error source and adjustment methods, and prints the correction according to actual observation of SLR; Then introduces classification and covariance matrix of measurement noise, brings in tokens of satellite azimuth, signal-to-noise ratio and signal strength, meanwhile, and lists random models, features of satellite azimuth, signal-to-noise ratio and signal strength.(2) This paper proposes time-differenced method of measurement noise, including correlation differential operator, semi-partial correlation differential operator and independent differential operator. Then, analyze the requirement of three differential operators on original sampling rate, sensitivity to systemic error, the estimation to measurement noise. Analyze in detail the influence of correlation in original data in the process using differential operator to estimate measurement noise.(3) Using carrier phase observations of GPS/BDS/DORIS(ionosphere equability /anomaly) as experiment data, and eventually chose three-order differential operator after pretreatment to estimate phase measurement noise, then according the estimation results analyze the relationship between satellite azimuth and phase observation in BDS B1, GPS L1 and DORIS L1, and count the RMSE by the methods of probable error and standard deviation when the measurement noise tends to be stable. The result presents that there is obvious correlation between observation accuracy and satellite azimuth. Then according to the comparison with the estimate results in equability ionosphere and in anomaly ionosphere, it is show that the RMSE using probable error method is more credible when the ionosphere is anomaly. Meanwhile, the ionosphere has great influence on the observation in GPS/BDS/DORIS, which is a necessary topic that deserve considering.(4) Using observations of SLR system(ionosphere equability/anomaly) as experimental data, the theoretical and observed value of the distance between the satellites and stations are used for residual statistics. Meanwhile, this dissertation uses time-differenced method to estimate measurement noise of distance, with three order differential operator. Besides, match the result and elevating angle with epoch, and count the RMSE by the methods of probable error and standard deviation. The results show that the observation precision of SLR is obvious correlation with elevating angle, and there is no obvious differential in observation accuracy with ionosphere smooth and anomaly. Experimental analysis indicates that the process of SLR observation is not affected by the ionosphere, and it's in accordance with the principle.