Chinese English

A method of accurate positioning; transmissions of an electromagnetic position fixing system are received at known positions ashore and the offsets between absolute known positions and system positions are transmitted to the ship in the vicinity. The offsets are applied to the measurements of the ship's receiver.

一种精确定位的方法；岸上的已知点接收到电磁定位系统发射的信号后，将已知绝对位置和系统之间的差值传送到附近的船舶，该差值被应用到船上接收机的测量中。

In mapping, the difference in unit contraction along the grain structure of the material as compared to the unit contraction across the grain structure; frequently refers to photographic film and papers and to map materials in general.

在制图中，沿制图材料晶体结构方向的单位收缩同垂直材料晶体结构方向的单位收缩之间是不同的；通常往往指摄影胶片和纸以及制图材料。

The bending of the RAYS of RADIANT ENERGY around the edges of an obstacle, or when passing near the edges of an opening, or through a small hole or slit, resulting in the formation of a SPECTRUM, or arrangement by WAVE LENGTH of component WAVES, producing, for visible WAVE LENGTHS, the chromatic SPECTRUM. The bending of a WAVE as it passes an obstruction.

辐射能的射线在通过障碍物边缘、小孔的边缘、小洞或者狭缝时弯曲，导致形成光谱或者各种波长的单色光，对于可见光波段，产生彩色光谱。 波在通过障碍物时产生弯曲的现象。

A model representing the terrain surface by a collection of digital data, mainly coordinates in three dimensions, x, y, and z, and a digitally defined method to interpolate arbitrary terrain heights in between the stored values. Not to be confused with digital cartographic model which may also contain digital data representing terrain, but in a form suitable for the drawing of a particular kind of map.

（DTM）。通过大量的数字数据和数字插值方法表示地形表面的一种模型，数字数据坐标主要采用x、y、z三维形式，数字插值方法用于根据已知存储值插值得到任意位置地形高度。不要同也可能包含数字数据来表示地形的数字制图模型相混淆，但是它是采用适于绘制特定类型地图的形式。

A computer aided device equipped with a digitizing table and a CURSOR for digitally capturing graphical data (pictures, charts), usually based on vector-techniques (as opposed to a SCANNER). The digitizing table consists of a gridded electrical network under the table's surface which allows an automatic computation of the planar x/y coordinates of a cursor's position. Lines are sequentially scanned by moving the cursor along the position and identifying the appropriate symbol on a menu.

一种计算机辅助设备，装备有数字化板和数字化鼠标，通常基于矢量技术（与扫描仪正相反）。数字化鼠标用于获取图形的数字数据。数字化板由位于数字化板表面下的电子格网组成，它允许自动计算数字化鼠标的平面x/y坐标。通过移动数字化鼠标顺序扫描每一条线，并在菜单上确定合适的符号。

An artifi­cial ditch to hold, or control the FLOW of water. An artificial EMBANKMENT to contain or hold back water. In GEOLOGY, a tabular body of IGNEOUS ROCK molded from molten ROCK within a fissure.

一种用来阻挡或者控制水流的人造沟渠。 一种人造的筑堤,用来容纳或者阻挡水。 在地质学中，指由狭长裂缝中的熔融岩形成的扁平的火成岩。

A parameter relating the precision of the position (and/or an unknown auxiliary) provided by a positioning system to that of the "observed quantities" directly measured by the system. DOP is a measure of the influence of the geometry of loci on the precision of position fixing. DOP is frequently used with a qualifying term such as geometric (GDOP), horizontal (HDOP), vertical (VDOP) etc. to indicate that DOP is related to all or some unknown quantities.

（DOP）。一个表示定位系统定位精度的参数。DOP度量接收机和卫星形成的几何形状对定位精度影响程度。DOP经常同术语例如几何误差放大因子（GDOP），平面位置误差放大因子（HDOP）和高程误差放大因子（VDOP）等一同使用，表明DOP同所有的或者某些未知的量相关联。

The vertical angle, at the eye of an observer between the horizontal and the LINE OF SIGHT to the APPARENT HORIZON. Also called dip of the horizon or depression of the horizon. The angle between the horizontal and the LINES OF FORCES of the EARTH's MAGNETIC FIELD at any point. Also called magnetic dip or magnetic inclination.

在观察者眼睛处，水平线与观察者视线形成的夹角。也称为水平倾角或者地平俯角。在地球磁力场任一点磁力线同水水平面之间的夹角，也称为magnetic dip 或者 magnetic inclination（磁倾角）。

An instrument for measuring MAGNETIC DIP. It consists essentially of a DIP NEEDLE or MAGNETIC NEEDLE, suspended in such manner as to be free to rotate about a horizontal AXIS. Also called IN­CLINOME­TER, or dipping compass. See also EARTH INDUCTOR.

测量磁倾角用的设备。本质上磁倾仪是由一个悬挂的磁倾针或者磁力针组成，磁力针采用悬挂的方式目的是能够围绕水平轴自由旋转。也称为倾角计，或者磁度仪。亦可参见earth inductor（地磁感应器）。