基于JSCORS的无验潮水下地形测量研究          下载免费PDF全文

李昱  阎成赟 《海洋测绘》2014,(3):48-51

提出了一种无验潮水下地形测量方法,利用长江江苏段沿岸的控制点资料,基于分段二次曲面与BP神经网络拟合算法建立似大地水准面精化模型;利用该模型换算测深点高程数据文件,并输出数据成图。经多方面精度测试比对,此方法能够获得高精度的水底点高程。  相似文献   

北斗伪距单点定位与差分定位结果精度分析          下载免费PDF全文

陆亚峰  蒋海林  彭遥 《海洋测绘》2014,(4):28-30

首先介绍了北斗伪距单点定位、伪距差分定位的基本原理和数学模型,然后根据自编程序,利用同济大学TJA站8天的数据进行计算及分析。结果显示:北斗伪距单点定位的精度平面方向上达到3.5m以内,高程方向优于8m,满足普通导航定位的需求。北斗差分定位的精度较伪距单点定位精度有了较大提高,其精度平面上达到1m以内,高程方向优于1.5m,能满足较高精度的需求。  相似文献   

���ھ��ܵ��㶨λ��½���ɻ����ܽ�����½�����о�     

֣��  ����  ������  ����Ϫ 《大地测量与地球动力学》2014,34(6):157-161

??????????λ???????????μ????????????????????????÷?????????????0.5 m????????????0.2 m??????????????????????????????????????????????????÷???????????????????????2 h????????λ??  相似文献   

����VRS�����ĸ߲�������ȵ��о�     

张红娟  侯海倩  张超 《大地测量与地球动力学》2014,34(1):165-168

???VRS???????????????????????????????????????????????????????????????????????????????????????????????????·??Ч???????????????????ò??????????????????????????????????????????????????????鶼????????????????????????????????VRS??????????????????????  相似文献   

���÷Dz�۲���ȷ���������Ǿ��ܹ�����Ӳ�ķ����о�     

刘伟平  郝金明  于合理  田英国 《大地测量与地球动力学》2014,34(1):169-172

?о????÷?????????????????????????????????????????????GPS???????????侫????????????????????????????????????????????????????30????????????????????????????????????R??T??N?????????0.032 m??0.084 m??0.078 m?????????????????0.18 ns???????????????????????????????????踴???????????????в???????????????????????????????????????????????????????????????о??н???????????  相似文献   

GEO���ǵ�����ӳ�ʱ�����п����׷���     

任夏  杨元喜 《大地测量与地球动力学》2014,34(2):115-119

?????GEO??????????????????????????????????????????????????????????????????????????????????????????е????????????в???????????????????????????????????????????????????????в??????????????????????????AR????в??????????????????????????????????????????????????????????????????????????????ζ??????????????????????????????????????????????????????????????????GEO?????????????Ч???  相似文献   

地热井井筒热效应研究          下载免费PDF全文

刘志涛  张志胜  胡松涛  吕明荟  谭现锋 《山东国土资源》2014,30(8)

在进行地热研究中需要对水位进行校正以消除井筒热效应,否则可能会形成错误的结论。在简要分析井筒热效应机理的基础上,对现有2种水位校正方法进行了论述,另外还基于积分原理提出了一种新的计算方法,并通过实例对各种方法的校正结果进行了对比分析。  相似文献   

高分辨率遥感卫星影像正射纠正模型的改进     

范玉茹  张巧茹  刘晓莉  邵彬 《测绘与空间地理信息》2014,(8):8-10

首先分析了地形起伏引起的像点位移原理,在此基础上,针对一般多项式只适用于平坦地区卫星影像正射纠正的不足,根据地形起伏引起的像点位移的数学推导公式,在多项式纠正方法中引入投影差改正,实验表明,该模型较一般多项式模型在x方向上精度有所提高,适用于高山地影像的正射纠正。  相似文献   

北斗三频数据实时周跳探测与修复方法对比分析     

肖国锐  隋立芬  甘雨  戚国宾 《测绘科学技术学报》2014,(5)

首先介绍了基于无几何相位组合、伪距相位组合以及LAMBDA算法进行三频周跳探测与修复的原理。然后对比了不同采样间隔下无几何相位组合和伪距相位组合周跳检验量的精度。无几何相位组合不受伪距噪声及多路径的影响,其周跳检验量的精度明显高于伪距相位组合的精度,周跳探测效果较好。最后从耗时和成功率两个方面对比分析了3种周跳修复方法的效果,结果表明无几何相位组合修复周跳时采用了搜索算法且搜索步长为经验值,其耗时和成功率都是最差的;伪距相位组合修复周跳时无需搜索,耗时最短,但其易受伪距噪声及多路径的影响,导致部分周跳修复失败;使用LAMBDA算法能有效减小搜索空间,并能在一定程度上控制历元间差分残留误差的影响,速度快且成功率高。综合考虑,建议使用筛选的两个无几何相位组合进行周跳探测,确认发生周跳后再使用LAMBDA算法进行修复。  相似文献   

A sun–crown–sensor model and adapted C-correction logic for topographic correction of high resolution forest imagery     

《ISPRS Journal of Photogrammetry and Remote Sensing》2014

Canopy shadowing mediated by topography is an important source of radiometric distortion on remote sensing images of rugged terrain. Topographic correction based on the sun–canopy–sensor (SCS) model significantly improved over those based on the sun–terrain–sensor (STS) model for surfaces with high forest canopy cover, because the SCS model considers and preserves the geotropic nature of trees. The SCS model accounts for sub-pixel canopy shadowing effects and normalizes the sunlit canopy area within a pixel. However, it does not account for mutual shadowing between neighboring pixels. Pixel-to-pixel shadowing is especially apparent for fine resolution satellite images in which individual tree crowns are resolved. This paper proposes a new topographic correction model: the sun–crown–sensor (SCnS) model based on high-resolution satellite imagery (IKONOS) and high-precision LiDAR digital elevation model. An improvement on the C-correction logic with a radiance partitioning method to address the effects of diffuse irradiance is also introduced (SCnS + C). In addition, we incorporate a weighting variable, based on pixel shadow fraction, on the direct and diffuse radiance portions to enhance the retrieval of at-sensor radiance and reflectance of highly shadowed tree pixels and form another variety of SCnS model (SCnS + W). Model evaluation with IKONOS test data showed that the new SCnS model outperformed the STS and SCS models in quantifying the correlation between terrain-regulated illumination factor and at-sensor radiance. Our adapted C-correction logic based on the sun–crown–sensor geometry and radiance partitioning better represented the general additive effects of diffuse radiation than C parameters derived from the STS or SCS models. The weighting factor W_t also significantly enhanced correction results by reducing within-class standard deviation and balancing the mean pixel radiance between sunlit and shaded slopes. We analyzed these improvements with model comparison on the red and near infrared bands. The advantages of SCnS + C and SCnS + W on both bands are expected to facilitate forest classification and change detection applications.  相似文献