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全站仪三角高程测量精度分析 总被引:1,自引:0,他引:1
本文通过对全站仪三角高程测量原理和影响全站仪三角高程测量精度的因素的分析,提出进行三角高程测量的适用性和提高全站仪三角高程精度的措施。 相似文献
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交会法测定水平位移的精度分析 总被引:5,自引:0,他引:5
对目前常用的几种典型交会测量方法进行了理论上的精度分析 ,并利用某大坝水平位移监测点的实测数据进行分析、验证 ,得出了一些有益的结论。 相似文献
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本文通过在衢州地区利用简化的BURSA-WOLF空间模型公式进行GPS坐标转换,比较各个模型对转换精度的影响,得出一些有利于工程应用的结论和建议. 相似文献
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In order to achieve the in-orbit absolute radiometric calibration of the operational meteorological satellites’ thermal infrared channels, China Radiometric Calibration Sites (CRCS) were established and the accuracy of the CRCS in-orbit field absolute radiometric calibration methods (FCM) for thermal infrared channels (TIR) was evaluated and analyzed based on TERRA/AQUA MODIS observations. Comparisons between the MODIS at pupil brightness temperatures (BTs) and the simulated BTs at the top of atmosphere using radiative transfer model (RTM) based on field measurements showed that the accuracy of the current in-orbit field absolute radiometric calibration methods was better than 1.0K (@ 300K) in thermal infrared channels. Therefore, the current CRCS field calibration method for TIR channels applied to Chinese meteorological satellites was with favorable calibration accuracy: for 10.5~11.5 μm channel was better than 0.747 K and for 11.5~12.5 μm channel was better than 0.851 K. 相似文献
239.
Geographic object-based image analysis (GEOBIA) produces results that have both thematic and geometric properties. Classified objects not only belong to particular classes but also have spatial properties such as location and shape. Therefore, any accuracy assessment where quantification of area is required must (but often does not) take into account both thematic and geometric properties of the classified objects. By using location-based and area-based measures to compare classified objects to corresponding reference objects, accuracy information for both thematic and geometric assessment is available. Our methods provide location-based and area-based measures with application to both a single-class feature detection and a multi-class object-based land cover analysis. In each case the classification was compared to a GIS layer of associated reference data using randomly selected sample areas. Error is able to be pin-pointed spatially on per-object, per class and per-sample area bases although there is no indication whether the errors exist in the classification product or the reference data. This work showcases the utility of the methods for assessing the accuracy of GEOBIA derived classifications provided the reference data is accurate and of comparable scale. 相似文献
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The increasing availability of high resolution imagery has triggered the need for automated image analysis techniques, with reduced human intervention and reproducible analysis procedures. The knowledge gained in the past might be of use to achieving this goal, if systematically organized into libraries which would guide the image analysis procedure. In this study we aimed at evaluating the variability of digital classifications carried out by three experts who were all assigned the same interpretation task. Besides the three classifications performed by independent operators, we developed an additional rule-based classification that relied on the image classifications best practices found in the literature, and used it as a surrogate for libraries of object characteristics. The results showed statistically significant differences among all operators who classified the same reference imagery. The classifications carried out by the experts achieved satisfactory results when transferred to another area for extracting the same classes of interest, without modification of the developed rules. 相似文献