gradient direction

It is proposed and discussed that the sun-pointing effect of daytime horizontal gradient vectors in the ionospheric TEC is such that: On the Northern Hemisphere, in winter, daytime course of gradient direction is the southeast-south-southwest;

文中提出并论述中纬度TEC水平梯度矢量的指日效应：在北半球，冬季时梯度矢量指向的昼间进程是东南南西南，方位角变化小，幅值与幅值变化亦小；

Thermal effects of laser medium have a serious effect on laser beam quality, slab laser medium can reduce the thermal focusing and stress birefringence effect by the light going through temperature gradient direction with a Zig-Zag optical path periodically.

激光介质的热效应对激光的光束质量有着严重的影响，板条激光介质可以利用Zig-Zag光路周期性穿越温度梯度方向以减小热聚焦及应力双折射效应。

We fit the iris to a circle and regard the upper-eyelid as a section of circular arc. Then we use the method of sub-pixel detection to detect sub-pixel edge and the method of Hough transform based on gradient orientation and gradient direction to detect circle.

本文将虹膜用圆来拟合，将上眼睑视为一段圆弧，研究并采用亚像素边缘检测方法检测亚像素级的虹膜边缘和基于梯度朝向和梯度方向信息的Hough变换的方法检测虹膜和眼睑。

We analyse the design of photoelectric digital level based on PSD, and design the laser gradient direction and measurement device based on PSD.

本文在分析浙江大学设计的基于PSD的光电式数字水准仪的基础上，提出设计基于PSD的激光坡度与指向装置。

To find the reconstruction curve, we can first choose an appropriate initial curve on the plane and move every point on this curve along the gradient direction of the field function.

为求得重建曲线，可先在平面上选取一条适当初始曲线，由初始曲线沿着场函数的梯度方向运动，其极限位置便为重建曲线。