發(fā)布時(shí)間：2018-04-26 05:17

  本文選題：激光遙感 + 激光測(cè)高系統(tǒng)　； 參考：《武漢大學(xué)》2013年博士論文

【摘要】：星載激光測(cè)高系統(tǒng)是一種主動(dòng)式測(cè)量系統(tǒng),通過(guò)接收衛(wèi)星平臺(tái)激光器發(fā)出的激光脈沖經(jīng)地表反射的微弱回波,并精確計(jì)算激光脈沖在衛(wèi)星和地面之間的渡越時(shí)間,得到衛(wèi)星和地表的距離；結(jié)合衛(wèi)星精密軌道和姿態(tài)數(shù)據(jù),生成激光腳點(diǎn)精確地理位置和高程結(jié)果。通過(guò)衛(wèi)星連續(xù)運(yùn)行,最終得到覆蓋地球表面DEM模型。 激光測(cè)高系統(tǒng)發(fā)射的激光脈沖能穿透植被獲取三維地形,具有傳統(tǒng)攝影測(cè)量方式無(wú)法取代的優(yōu)點(diǎn)；其激光發(fā)散角在亞毫弧量級(jí),水平定位精度和分辨率遠(yuǎn)遠(yuǎn)高于微波雷達(dá)方式；位于大氣透過(guò)窗口的1064nm波長(zhǎng)激光可以直接被冰蓋和海洋表面反射,幾乎沒(méi)有穿透效應(yīng),高程精度可達(dá)15cm。這些優(yōu)點(diǎn)使其廣泛用于南北極冰蓋變化監(jiān)測(cè)、極區(qū)附近海冰變化監(jiān)測(cè)、植被年際變化監(jiān)測(cè),少量用于海洋環(huán)境監(jiān)測(cè)等領(lǐng)域；如果作為遙感影像的地面高程控制點(diǎn),可以生成1：10000的大比例尺地形圖。 ICESat衛(wèi)星搭載的GLAS系統(tǒng)于2003年發(fā)射升空,在軌間斷運(yùn)行7年,是目前為止唯一一顆用于全球地表觀測(cè)的星載激光測(cè)高系統(tǒng)。對(duì)地球觀測(cè)的GLAS系統(tǒng)的觀測(cè)成果不僅包含器件本身所帶來(lái)的誤差,也包含如光束穿越大氣產(chǎn)生的散射和折射,由章動(dòng)和歲差等產(chǎn)生的固體潮汐等環(huán)境誤差,以及由地表斜率或粗糙度等引起的目標(biāo)誤差。因此,建立測(cè)高系統(tǒng)回波和誤差模型,以及完整的數(shù)據(jù)處理方法對(duì)激光測(cè)高系統(tǒng)參數(shù)設(shè)計(jì)、誤差評(píng)估和數(shù)據(jù)產(chǎn)品的有效性和準(zhǔn)確性至關(guān)重要。 論文針對(duì)具有全波形記錄功能、對(duì)地球觀測(cè)的星載激光測(cè)高系統(tǒng)進(jìn)行完整的回波理論和誤差分析研究,完成了由測(cè)高系統(tǒng)原始回波數(shù)據(jù)直至高程數(shù)據(jù)產(chǎn)品的完整數(shù)據(jù)處理流程,并編寫(xiě)了批量數(shù)據(jù)處理軟件。在回波理論方面,完善了星載激光測(cè)高系統(tǒng)固體地表的回波理論模型,建立了海洋表面回波理論模型,并完善了固體地表和海洋表面參數(shù)的反演理論；在誤差分析方面,完善了固體地表的激光測(cè)距誤差模型,建立了海洋表面距離和回波脈寬誤差模型,并建立了完整的星載激光測(cè)高系統(tǒng)腳點(diǎn)高程誤差分析模型；在數(shù)據(jù)處理方面,以GLAS系統(tǒng)為例,使用底層原始回波數(shù)據(jù)與ICESat衛(wèi)星輔助工程數(shù)據(jù)進(jìn)行粗略距離、精確距離、粗略高程和精確高程解算,生成最終高程數(shù)據(jù)產(chǎn)品,將中間過(guò)程和最終結(jié)果與NASA處理結(jié)果一一作對(duì)比驗(yàn)證,并改進(jìn)了若干數(shù)據(jù)處理方法；在數(shù)據(jù)應(yīng)用方面,結(jié)合美國(guó)宇航局GLAS測(cè)高數(shù)據(jù)、美國(guó)國(guó)家環(huán)境預(yù)報(bào)中心NCEP氣象數(shù)據(jù)和丹麥科技大學(xué)ALS機(jī)載激光雷達(dá)數(shù)據(jù),利用海洋回波模型和GLAS實(shí)測(cè)數(shù)據(jù)反演了海洋表面風(fēng)速、波高結(jié)果,利用ICESa衛(wèi)星交叉和重復(fù)腳點(diǎn)對(duì)估計(jì)了2003-2009年3月格陵蘭島2000m以上地區(qū)冰蓋高程變化,并改進(jìn)了交叉點(diǎn)的計(jì)算方法,利用ALS激光雷達(dá)數(shù)據(jù)生成GLAS激光腳點(diǎn)DEM圖用于評(píng)估GLAS高程測(cè)量精度。 使用海洋回波模型模擬的海洋回波與GLAS真實(shí)海面回波有很好的相似性,參數(shù)誤差小于6%；利用GLAS數(shù)據(jù)反演的海平面上方風(fēng)速與NCEP氣象數(shù)據(jù)風(fēng)速有較好的一致性；GLAS與TOPEX雷達(dá)測(cè)高數(shù)據(jù)計(jì)算的平均海平面也顯示出較好一致性。GLAS數(shù)據(jù)處理過(guò)程距離粗值偏差小于2.5cm,距離修正偏差小于3cm,固體潮汐修正小于3mm,由GLA01原始回波數(shù)據(jù)解算的最終高程結(jié)果與GLAS結(jié)果對(duì)比,在斜率和粗糙度較小冰蓋表面偏差可以控制在10cm以內(nèi)。利用腳點(diǎn)高程精度和空間分辨率更高的ALS機(jī)載激光雷達(dá)數(shù)據(jù)與GLAS高程數(shù)據(jù)對(duì)比,結(jié)果符合所建立的高程誤差模型,并驗(yàn)證在較平坦的冰蓋表面,GLAS系統(tǒng)高程精度可以達(dá)到設(shè)計(jì)值-10cm。利用GLAS交叉和重復(fù)腳點(diǎn)對(duì)格陵蘭島2000m以上地區(qū)冰蓋監(jiān)測(cè)結(jié)果表明,2003-2009年3月份其冰蓋表面高程年均增長(zhǎng)3.80cm,標(biāo)準(zhǔn)差為0.91cm,交叉點(diǎn)和重復(fù)點(diǎn)結(jié)果趨勢(shì)一致,重復(fù)點(diǎn)數(shù)量多但分布不均勻,使用ICESat數(shù)據(jù)分析格陵蘭地區(qū)冰蓋時(shí),較大區(qū)域適合使用交叉點(diǎn)方法,較小區(qū)域適合使用重復(fù)點(diǎn)方法。 論文最后加入了GLAS標(biāo)準(zhǔn)數(shù)據(jù)存儲(chǔ)格式、數(shù)據(jù)分類等級(jí)以及不同數(shù)據(jù)等級(jí)間的轉(zhuǎn)換關(guān)系,對(duì)于理解論文中數(shù)據(jù)處理和應(yīng)用有一定幫助；基于VS2008平臺(tái)用于激光測(cè)高系統(tǒng)數(shù)據(jù)處理的整套軟件也進(jìn)行了簡(jiǎn)單展示,包括使用C++語(yǔ)言編寫(xiě)的功能算子部分和VB語(yǔ)言編寫(xiě)的窗體操作部分,軟件集數(shù)據(jù)讀取、數(shù)據(jù)處理、數(shù)據(jù)分析和結(jié)果評(píng)價(jià)功能于一體。 論文中數(shù)據(jù)處理流程和關(guān)鍵技術(shù)在對(duì)地觀測(cè)的激光測(cè)高系統(tǒng)中具有較強(qiáng)通用性,對(duì)我國(guó)未來(lái)發(fā)射對(duì)地觀測(cè)星載激光測(cè)高系統(tǒng)的數(shù)據(jù)處理具有借鑒意義；回波理論和誤差模型對(duì)于星載激光測(cè)高系統(tǒng)的系統(tǒng)參數(shù)的優(yōu)化設(shè)計(jì)和測(cè)量誤差的評(píng)判具有重要意義。
[Abstract]:The satellite borne laser altimetry system is an active measurement system. By receiving the weak echo of the laser pulse from the satellite platform laser, and calculating the distance between the satellite and the ground accurately, the distance between the satellite and the ground is calculated accurately. Accurate location and elevation results. Finally, the DEM model covering the earth's surface is finally obtained through continuous operation of satellites.
The laser pulse emitted by the laser altimetry system can penetrate the vegetation to obtain the three-dimensional terrain, which has the advantages of the traditional photogrammetry. The laser divergence angle is at the sub milli arc, and the horizontal positioning accuracy and resolution are far higher than the microwave radar mode; the 1064nm wavelength laser located in the atmosphere through the window can be directly covered with ice cover and sea. Ocean surface reflection, almost no penetration effect, high range precision can reach 15cm., which make it widely used for monitoring change of Arctic ice cover, monitoring of sea ice change near polar region, monitoring of interannual variation of vegetation, small amount of application in marine environment monitoring and so on. If as ground elevation control point of remote sensing image, it can generate a big ratio of 1:10000. A topographic map of a ruler.
The GLAS system carried by the ICESat satellite is launched in 2003 and is running intermittently for 7 years. It is the only star borne laser altimetry system for global surface observation so far. The observation results of the earth observation GLAS system include not only the error caused by the device itself, but also the scattering and refraction of the beam through the atmosphere. The environmental errors such as nutation and precession, such as solid tides, as well as the target error caused by the slope or roughness of the surface. Therefore, the establishment of the echo and error model of the altimetry system and the complete data processing method are very important to the design of the parameters of the laser altimetry system, the error evaluation and the validity and accuracy of the data products.
In view of the full waveform recording function, the complete echo theory and error analysis of the earth observation satellite borne laser altimetry system are studied. The complete data processing flow from the original echo data of the altimetry system to the high range data product is completed, and the batch data processing software is written. In the echo theory, the satellite load is perfected. The theoretical model of the echo of the solid surface of the laser altimetry system is established, and the theoretical model of the sea surface echo is established, and the inversion theory of the surface and ocean surface parameters is perfected. In the error analysis, the laser range error model of the solid surface is perfected, the distance of the ocean surface and the error model of the echo pulse width are established, and the integrity of the model is established. In the aspect of data processing, using the GLAS system as an example, using the underlying original echo data and the ICESat satellite aided engineering data for rough distance, accurate distance, rough elevation and accurate elevation, the final elevation data products are generated, and the intermediate process and final result and NASA are used in data processing. The results are compared and verified, and a number of data processing methods are improved. In the field of data application, the sea surface wind speed is retrieved from the ocean echo model and the measured data from the ALS airborne laser radar data of the Technical University of Denmark, the American National Environment Forecast Center NCEP meteorological data and the Technical University of Denmark ALS airborne laser radar data. The results of wave height are estimated by using ICESa satellite crossover and repetition foot point to estimate the change of ice cover elevation in the area above 2000m of Greenland in March, and improve the calculation method of intersection point. Using ALS laser radar data to generate GLAS laser foot point DEM map to evaluate the accuracy of GLAS elevation measurement.
The sea echo simulated by the sea echo model has good similarity with the real sea surface echo of GLAS, and the parameter error is less than 6%. The wind speed above the sea level retrieved from the GLAS data is in good agreement with the wind speed of the NCEP meteorological data; the flat average sea level of the GLAS and the TOPEX radar altimetry data also shows a good consistency.GLAS number. According to the processing process, the distance deviation is less than 2.5cm, the distance correction deviation is less than 3cm, the solid tide correction is less than 3mm, the final elevation result calculated by the original GLA01 echo data is compared with the GLAS result, and the surface deviation of the slope and the roughness of the smaller ice cover can be controlled within 10cm. The higher accuracy of the foot point and the higher spatial resolution of ALS can be obtained. The airborne lidar data are compared with the GLAS elevation data. The results conform to the established elevation error model and verify that the GLAS system elevation accuracy can reach the designed value -10cm. on the flat surface of the ice cover. The results of the ice cover monitoring over the 2000m area above Greenland, using the GLAS cross and repeated feet, show that the ice cover table in March was 2003-2009. The average elevation is up to 3.80cm, the standard deviation is 0.91cm, the intersection point and the repeat point are the same, the number of repeat points is much more, but the distribution is uneven. When using ICESat data to analyze the ice cover in Greenland area, the larger area is suitable for using the intersection point method, and the smaller area is suitable for using the repeat point method.
At the end of the paper, the GLAS standard data storage format, the data classification level and the conversion relationship between different data levels have been helped to understand the data processing and application in the paper, and the software for the data processing of the laser altimetry system based on the VS2008 platform is also simply displayed, including the work written in the C++ language. Energy operator part and form operation part written in VB language, software set data reading, data processing, data analysis and result evaluation function in one.
The data processing flow and key technology in this paper have strong generality in the ground observation laser altimetry system, and have reference significance to the data processing of the satellite borne laser altimetry system in our country in the future, and the optimization design and measurement error of the echo theory and error model for the system parameters of the spaceborne laser altimetry system The judgment is of great significance.

【學(xué)位授予單位】：武漢大學(xué)
【學(xué)位級(jí)別】：博士
【學(xué)位授予年份】：2013
【分類號(hào)】：P225.2;P236

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本文編號(hào)：1804646