【摘要】：在采集、獲取信號的過程中，由于外界多種因素的影響，造成信號中含有一些噪聲。噪聲成了影響信號質(zhì)量的一個最主要的因素，對我們提取信號中的有用信息造成一種影響。因此，消除噪聲帶來的不利影響成為學者和專家最關注的話題之一。 小波分析理論具有的分時分頻精細表達和多尺度多分辨率分析等獨特優(yōu)勢，，已經(jīng)逐漸發(fā)展成為動態(tài)測量信號處理領域中的重要技術手段，在實際工程應用中越來越廣泛，尤其在信號處理方面，比如：信號去噪、信號壓縮等。本文將小波分析應用到GPS信號處理中，剔除信號中的噪聲。 GPS在實際生產(chǎn)測量過程中，外界環(huán)境的影響，造成GPS接收到的信號發(fā)生變化，即在信號中含有一些噪聲，影響測量的精度。為了消除GPS信號中的噪聲，文中采用小波分析去噪方法中的閾值去噪法對信號進行去噪，小波閾值去噪法在最小均方誤差意義下可達近似最優(yōu)。通過對國內(nèi)外研究現(xiàn)狀、小波函數(shù)的特點、選取的原則等進行一定的研究，設計文章研究的思路與方法，利用實驗結果證明研究方法的可行性。 本文利用matlab編程將實際應用中采集的一組數(shù)據(jù)進行提取，提取GPS信號中的兩顆衛(wèi)星載波相位L1上的C/A碼，分別通過不同歷元間求出單差以及雙差，再分別選取一定的小波基函數(shù)和選取特定的閾值對其進行小波分析去噪，通過信噪比、均方根誤差作為小波函數(shù)和閾值選取的標準及去噪效果的評價標準，將獲取的不同小波去噪結果進行對比，根據(jù)對比的結果確定選擇哪種小波，選取何種閾值，確定小波函數(shù)和閾值以后，最后通過最新的一種評價指標——平滑度來確定最終去噪的效果。 實驗結果表明：選用demy小波函數(shù)和Penalize low確定的閾值達到了GPS單差和雙差數(shù)據(jù)去噪的理想效果。為完善小波分析去噪理論，減少GPS數(shù)據(jù)處理的中產(chǎn)生的一些誤差奠定了一定的理論及實踐基礎。
[Abstract]:In the process of signal acquisition and acquisition, there are some noises in the signal due to the influence of many external factors. Noise is one of the most important factors affecting the quality of signal, which has an effect on the extraction of useful information from the signal. Therefore, eliminating the adverse effects of noise has become one of the topics most concerned by scholars and experts. Wavelet analysis theory has the unique advantages of time-sharing and frequency-sharing fine expression and multi-scale multi-resolution analysis, which has gradually developed into an important technical means in the field of dynamic measurement signal processing, and has been more and more widely used in practical engineering. Especially in signal processing, such as: signal denoising, signal compression and so on. In this paper, wavelet analysis is applied to GPS signal processing to eliminate the noise in the signal. In the process of actual production and measurement of GPS, the influence of external environment causes the signal received by GPS to change, that is, there is some noise in the signal, which affects the accuracy of measurement. In order to eliminate the noise in GPS signal, the threshold de-noising method of wavelet analysis is used to Denoise the signal. The wavelet threshold de-noising method is approximately optimal in the sense of minimum mean square error. The present situation of the research at home and abroad, the characteristics of wavelet function and the principle of selection are studied to design the ideas and methods of this paper, and the feasibility of the research method is proved by the experimental results. In this paper, a set of data collected in practical application is extracted by matlab programming, and the C / A codes on the carrier phase L1 of two satellites in GPS signal are extracted, and the single difference and double difference are obtained from different epoch, respectively. Then select a certain wavelet basis function and select a specific threshold to Denoise by wavelet analysis. The signal-to-noise ratio (SNR) and root mean square error (RMS) are used as the criteria of wavelet function and threshold selection and the evaluation standard of denoising effect. The different wavelet denoising results obtained are compared. According to the comparison results, which wavelet is selected, what kind of threshold is selected, after determining the wavelet function and threshold, Finally, the final denoising effect is determined by the latest evaluation index-smoothness. The experimental results show that the demy wavelet function and the threshold determined by Penalize low can achieve the ideal effect of GPS single difference and double difference data denoising. It lays a theoretical and practical foundation for perfecting the denoising theory of wavelet analysis and reducing some errors in GPS data processing.
【學位授予單位】：東華理工大學
【學位級別】：碩士
【學位授予年份】：2013
【分類號】：P228.4

【參考文獻】

相關期刊論文 前10條

1 陳向陽;;基于小波分析的GPS雙差觀測數(shù)據(jù)消噪方法研究[J];測繪工程;2011年06期

2 曲國慶;黨亞民;章傳銀;;變形監(jiān)測信號消噪的不確定度[J];測繪科學;2007年05期

3 張風霜;楊國華;;GPS連續(xù)觀測資料小波變換質(zhì)量評價探討[J];測繪科學;2011年06期

4 黃丁發(fā),卓健成;GPS相位觀測值周跳檢測的小波分析法[J];測繪學報;1997年04期

5 郭秋英;張邦花;;小波變換在GPS快速定位數(shù)據(jù)處理中的應用[J];測繪信息與工程;2007年04期

6 曾遠星;張書畢;卞和方;侯東陽;;基于haar小波基周跳探測與修復方法[J];測繪信息與工程;2011年01期

7 夏開旺;田林亞;楊永平;;基于小波分析的壩區(qū)GPS信號噪聲研究[J];水電自動化與大壩監(jiān)測;2006年04期

8 何永紅;文鴻雁;靳鵬偉;;第二代小波在GPS雙差觀測值消噪中的應用[J];大地測量與地球動力學;2010年03期

9 李春庚,王波,王百鎖;基于小波理論的GPS信號分析[J];大連海事大學學報;2002年03期

10 石為人,羅雪松,胡寧;基于小波多分辨率分析的信號消噪[J];重慶大學學報(自然科學版);2002年06期

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