期刊文献+
共找到2篇文章
< 1 >
每页显示 20 50 100
顾及多积分时间特性的GF-4卫星PMS传感器交叉辐射定标 被引量:1
1
作者 韩杰 陶醉 +2 位作者 谢勇 刘其悦 石宏斌 《测绘学报》 EI CSCD 北大核心 2020年第10期1311-1320,共10页
针对GF-4卫星PMS传感器具备5个积分时间的成像特性,提出一种基于辐射区域网平差的交叉辐射定标方法。首先,利用敦煌辐射校正场地区时间序列有效MODIS影像集,构建该区域高精度BRDF模型。其次,考虑BRDF和SBAF校正,从该地区Landsat-8卫星OL... 针对GF-4卫星PMS传感器具备5个积分时间的成像特性,提出一种基于辐射区域网平差的交叉辐射定标方法。首先,利用敦煌辐射校正场地区时间序列有效MODIS影像集,构建该区域高精度BRDF模型。其次,考虑BRDF和SBAF校正,从该地区Landsat-8卫星OLI影像和PMS影像中提取辐射控制点。然后,设置DN值和CV限制条件,在凝视成像状态下从不同积分时间PMS影像中提取辐射连接点。最后,利用新建定标模型计算各积分时间状态下的定标系数。验证结果表明,不同积分时间的各波段平均绝对定标精度均优于5.18%,且不同积分时间影像间各波段辐射差异最高降低36.64%。同时,探讨了辐射控制点分布、BRDF、SBAF和辐射连接点筛选条件对定标结果的影响,为进一步优化PMS传感器交叉辐射定标流程提供重要参考。 展开更多
关键词 GF-4 多积分时间 辐射区域网平差 BRDF SBAF
下载PDF
Milling stability analysis using the spectral method 被引量:11
2
作者 DING Ye ZHU LiMin +1 位作者 ZHANG XiaoJian DING Han 《Science China(Technological Sciences)》 SCIE EI CAS 2011年第12期3130-3136,共7页
This paper focuses on the development of an efficient semi-analytical solution of chatter stability in milling based on the spectral method for integral equations. The time-periodic dynamics of the milling process tak... This paper focuses on the development of an efficient semi-analytical solution of chatter stability in milling based on the spectral method for integral equations. The time-periodic dynamics of the milling process taking the regenerative effect into account is formulated as a delayed differential equation with time-periodic coefficients, and then reformulated as a form of integral equation. On the basis of one tooth period being divided into a series of subintervals, the barycentric Lagrange interpolation polynomials are employed to approximate the state term and the delay term in the integral equation, respectively, while the Gaussian quadrature method is utilized to approximate the integral tenn. Thereafter, the Floquet transition matrix within the tooth period is constructed to predict the chatter stability according to Floquet theory. Experimental-validated one-degree-of-freedom and two-degree-of-freedom milling examples are used to verify the proposed algorithm, and compared with existing algorithms, it has the advantages of high rate of convergence and high computational efficiency. 展开更多
关键词 milling stability delayed differential equation integral equation spectral method Floquet theory
原文传递
上一页 1 下一页 到第
使用帮助 返回顶部